Landracing Forum

Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Simspeed on July 22, 2019, 10:17:56 PM

Title: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:17:56 PM
(The project design is now at V.6.1)

Hi Everyone? We?re transitioning the Aerodynamic Forum post http://www.landracing.com/forum/index.php?topic=17667.0 (http://www.landracing.com/forum/index.php?topic=17667.0) Frontal Area / Cd Numbers to a LSR design project hosted here in the Build Diaries forum.  We?ve received great response from experienced and accomplished forum members for guidance and input to our ongoing attempt to design an unlimited wheel driven (UWD) streamliner.  V.6.1 has abandoned the IC powered electric gen/motor concept, and now proposes the use of a direct drive Liquid Piston 4 rotor IC engine for power.

In following posts we will outline the project build criteria, along with presentation of 3D drawings of the current Simspeed LSR V.6.1 design for member review and comments.  Our goal is to engage with those of you who have been down this road before, and have the records and experience you're willing to share with a rookie designer like myself.  V.6.1 has evolved here on the forum based on shared experience of numerous racers and we are highly in your debt for those contributions. 

We believe 600 mph is an obtainable wheel driven record; and our intention is to parent a consensus design developed here on the forum capable in theory of pushing the UWD envelope toward that record speed.  Hopefully, when a consensus on the project design has been reached by member vote, we can source funding and assemble a build team to make a record breaking effort.

As an LSR novice, albeit one with a drag racing background, I know my limitations are numerous.  There is much to be learned on my part, and I'm grateful for the opportunity to share my project goals with you and receive feedback from those willing to participate in this conceptual project.  Thanks again for those of you who have opened up with great suggestions and critiques, and thanks in advance for future involvement of forum members. God bless? Terry Peterson
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:30:52 PM
Simspeed UWD LSR V.5.5 Specifications

FIA Competition Class - Special Construction
    Unlimited Wheel Driven

Chassis Construction:
    2" Carbon Fiber Square Tubing w/ Bonded 3D Printed Titanium Connectors
    Carbon Fiber Brace Plating w/ Stainless Button Hex Fasteners
    2 Wheel FWD
    2 Solid Mount Trailing Wheels

Front Steering Differential
      Solid mount
      Front Wheel Drive
      2 Powered Wheels

Drive Wheel/Tires
    Machined Aluminum
    SlipNOT (tm) #2 Metal Sputter Coat Traction Surface

Body Construction:
    Molded Composite - Fiberglass
    Canopy
      Vacuum Formed Polycarbonate
      Aluminum Framework
    Vertical Tail Fin
      Molded Composite - Carbon Fiber

Propulsion:
    Internal Combustion Engine

Power Source
    Liquid Piston - 4 Rotors
        5.48 liters
        334.401 cu.in.
    Estimated Power Output - 1000 hp/rotor x 4 = 4000 hp
    Fuel
        Methanol

Power Adder:
    Nitrous Oxide
    160 lbs onboard   

Drive Train:
    Direct Drive Differential
    Quick Drive (tm) Torque Coupling
    4000 rpm Lock Up

Negative Pressure Downforce:
    Engine driven vacuum pump sucking air from skirted cavity beneath body floor pan.

Braking:
    Parachutes
        Vehicle (2)
        Driver Module(2)
    Dual Caliper Engine Brake

Dimensions:
    Driver's compartment:
        Width
            17.4" @ Shoulders
            17.4" @ Hips
        Length
            66.5" @ Seat back to foot well
        Max Driver Height
            6'2"      

Overall Dimensions:
    Vehicle Body:
        30' Length
        136" Wheel Base
        25"    Height @ Canopy to ground
        24"    Max Body Width
        Weight:  Estimated 3000/3500 lb

Frontal Area:
    3.97 sq.ft.

Coefficient of Drag: .09 estimated
Center of Gravity:  TBD
Center of Pressure:  TBD
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:35:00 PM
The V.5.2 body is a sloped nose concept using ground skirts with active aero wing and fixed tail fins.  The parachute tail cone is hydraulically activated.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:38:57 PM
The tail cone mechanism is actuated via a long center shaft screw fitted to a hydraulic ram cylinder forward mounted behind the rear drive wheels.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:40:59 PM
The driver sits midship between the fore and aft IC/Gen powerplants and sights the run down a long window canopy.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:47:50 PM
The chassis view shows the split power plants requiring no mechanical linkage to the electric wheel motors.  Nitrous oxide tanks and oil/fuel tanks are mounted along side each power plant with a forward weight bias for Cg ahead of the center mounted active anhedral wing.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 10:58:32 PM
The anhedral wing articulates about a center pivot point welded a top the driver's cage and backbone of the chassis.  A hydraulic ram rotates the wing through a 15.4 degree range of motion providing aero downforce via angle of attack positioning.  The wing itself is based on a pure ellipse offering zero lift or downforce at zero angle of attack.  The anhedral wing shape and position is based on an Air Bus patent  http://www.flightstory.net/20120101/airbus-files-patent-for-downward-facing-winglet (http://www.flightstory.net/20120101/airbus-files-patent-for-downward-facing-winglet)
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:03:56 PM
Here is the hydraulic ram placement for the tail cone mechanism.  The idea will be to charge a hydraulic accumulator prior to each run for ram operation to open the tail cone and deploy the parachutes.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:13:57 PM
The front drive wheels, suspension and steering components are mounted on dual a-arms with forward mounted shock absorbers.  In the cut away drawing 5.2.19 we see the drive motors mounted to steering spindles hung on a common suspension knuckle with counter pivoting steering links running back to the vertical mounted 90 degree steering box.  The suspension knuckle could be machined from a solid billet or welded fabrication.

The opposing a-arms do change the caster angle a total of 2.2 degrees through the limited range of motion.  The caster angle is set at 13 degrees and I feel that 1.1 degrees either direction is not a deal breaker for the design.  I could be wrong of course so if anyone has a better handle on this please let us know.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:15:26 PM
The front drive, suspension, and steering components shown in isolation.
Title: Re: Simspeed UWD LSR Design Project
Post by: RansomT on July 22, 2019, 11:15:52 PM
Having just a bit of nitrous oxide experience, how would one sustain acceptable flow & pressure using that amount of nitrous over a 7 mile run?
Title: Re: Simspeed UWD LSR Design Project
Post by: Stainless1 on July 22, 2019, 11:24:28 PM
Having just a bit of nitrous oxide experience, how would one sustain acceptable flow & pressure using that amount of nitrous over a 7 mile run?

I could tell ya over a beer at Bonneville...... of course we only used it for 52-58 seconds..... I didn't see how much N20 Terry was planning to carry, I would guess a lot... 80-120 lbs would be required.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:28:44 PM
The IC/Gen power plant is based on Mazda 13b rotors mounted in custom peripheral port housings shared with YASA P400 electric motor components.  Each single rotor/gen engine is mated to a matching rotor/gen engine to form a 2rotor/2gen assembly utilizing a common drive shaft.  Exhaust and intake housings are shared with a second 2rotor/2gen assembly to form a 4 rotor / 4 gen power plant.  Cooling for the power plants is shared internally in the common housings.  Both oil and fuel are cooled by Nitrous Oxide gases flowing through pressurized internal coils mounted inside on board tanks.  NOS used for cooling will be rerouted to IC engines as the dry gas power adder.  Wet systems will be incorporated for direct injection from onboard bottles.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:29:46 PM
Tube chassis design
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:35:23 PM
Having just a bit of nitrous oxide experience, how would one sustain acceptable flow & pressure using that amount of nitrous over a 7 mile run?
Quote
I could tell ya over a beer at Bonneville...... of course we only used it for 52-58 seconds..... I didn't see how much N20 Terry was planning to carry, I would guess a lot... 80-120 lbs would be required.

Having shared a few beers with Stainless I can tell you I'll be relying heavily on his experience with N20 supercharging for the needed power this effort will take.  After our visit in Denver earlier this summer I could tell his success in setting records will N20 was the way to go for this project.  Thanks to you both... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 22, 2019, 11:43:14 PM
I could tell ya over a beer at Bonneville...... of course we only used it for 52-58 seconds..... I didn't see how much N20 Terry was planning to carry, I would guess a lot... 80-120 lbs would be required.

Not knowing for certain Stainless I packaged all the chassis design could carry which is eight 20 lb bottles for 160 lbs total.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 23, 2019, 06:54:58 PM
Added the plating around the driver's cage and took Tom B's advice and removed the tubing below the driver's butt and added plating flush with the bottom of the cage to give another 1 5/8" head room for the driver (shown in yellow).  Thanks Tom... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on July 24, 2019, 06:30:07 PM
You might want to get pre-approval from SCTA on that since the roll cage tubing rule includes below the driver. See rule 3 B 1.
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 24, 2019, 09:44:13 PM
You might want to get pre-approval from SCTA on that since the roll cage tubing rule includes below the driver. See rule 3 B 1.
  Sid.

Thanks for the heads up Sid.  There will be a lot to submit for approval with this car.  Not necessarily looking to compete for SCTA records but like was noted early on its better to conform to SCTA rules just to get seat time at their meets.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on July 25, 2019, 01:56:28 AM
So if your plan is to run FIA records I think you might have a couple of issues with your design. I believe you can't have active aero as it's considered an aircraft on the ground plus a hybrid vehicle is required to be able to propel itself with the primary engine. It's been a while since I read this stuff but I'm pretty sure those two are right. Anybody else know better?
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: Rex Schimmer on July 25, 2019, 07:08:44 PM
Sid, Not sure that Terry's drive concept would classify as hybrid it is really just an electric transmission. Very similar to modern day diesel or gas turbine locomotives. He could also use an hydraulic hydro static transmission, engines turn pumps and pumps drive hydraulic motors that drive wheels, which is the "mechanical" equivalent of what he is proposing to do with the electric drive. Terry, don't even think about using an hydraulic hydrostatic drive, to heavy and not nearly as efficient as your electric concept. I am sure that you have already answered this question some where but why not just "bin" the engines and replace with some of the new high tech batteries? Probably to much weight.

Rex
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 25, 2019, 11:51:36 PM
So if your plan is to run FIA records I think you might have a couple of issues with your design. I believe you can't have active aero as it's considered an aircraft on the ground plus a hybrid vehicle is required to be able to propel itself with the primary engine. It's been a while since I read this stuff but I'm pretty sure those two are right. Anybody else know better?
  Sid.

Sid...I'll have to check up on the active aero rule. The wing in this project offers no lift...just downforce similar to Rob's Carbinite wing.  I believe active aero is essential to maximize traction potential of virtually any liner. 

Not sure what is meant by propelled by the primary engine.  Are the batteries considered the primary engine for an electric car?  A hybrid can be any combination of power units gas, diesel, batteries or no batteries, or fuel cells.  In the case of this project the IC engines are the not only the primary engines (power units) they are the only power generators in the drive train.   The combination of IC and electric gen/motors is described as a hybrid in the lexicon but is it really?  Like Rex describes below its the same concept as a diesel electric drive used in heavy machinery.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 25, 2019, 11:59:33 PM
Sid, Not sure that Terry's drive concept would classify as hybrid it is really just an electric transmission. Very similar to modern day diesel or gas turbine locomotives. He could also use an hydraulic hydro static transmission, engines turn pumps and pumps drive hydraulic motors that drive wheels, which is the "mechanical" equivalent of what he is proposing to do with the electric drive. Terry, don't even think about using an hydraulic hydrostatic drive, to heavy and not nearly as efficient as your electric concept. I am sure that you have already answered this question some where but why not just "bin" the engines and replace with some of the new high tech batteries? Probably to much weight.

Rex

Hi Rex... yes your are correct, weight is almost twice for the BB3 electric liner (8000 lbs) as what the Simspeed liner will likely weigh. Plus, service between runs will be much quicker for this drive system than recharging batteries and battery performance will degrade with each run as claimed by the BB3 team.  Most importantly IMHO the frontal area can be significantly smaller with the rotary/gen power than what's needed to carry 2mW+ of batteries.  I believe the combo we've presented will be power competitive with an overall smaller body geometry.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 26, 2019, 12:14:06 AM
I ran across a 2012 thesis paper by Carrington Bork on the aerodynamic development of the Buckeye Bullet 3 electric liner.  Very informative and useful as a comparison for the Simspeed project.  The approach they took on the drive system is quite a bit different than what we are contemplating but that's just shows how much the technology has advanced in the past 7 years.

Of interest was their Cd and frontal area calculations and how that relates to what we've come up with.  Their discussion on driver in the middle (DIM) vs driver in front (DIF) piqued my interest.  So much so that I'm now looking at a DIF design and how  drag can be significantly reduced by lessening the frontal area with a forward mounted cockpit.  I'll have something to show on that in a few days.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on July 26, 2019, 07:55:45 AM
Hi Terry,
From a complete novice AND vintage bike rider (  :dhorse: )!!!

Was looking at this frontal forest of tubes and your narrow vision slit area, surely less than 5 degree vision cone and a recipe for no side vision at all, important if you want to foresee in good time obstacles, pot holes, barrels, cones, or whatever else delimit the course 1 or 2 seconds in front of you @ 450mph!!!

(http://www.landracing.com/forum/index.php?action=dlattach;topic=17792.0;attach=62343;image)

Obviously, if you go forthwith with your front driver compartment, it will solve this issue at once!!!

Does some one higher up insist on so much tubing? If you slide to a rest it's useless, if you somersault, surely you want a bit of crumble availability to absorb some of the impacts and the G forces before they get to the driver???

More to the point, is carbon fiber still a no-no in LSR circles??? An F1 driver's cage is virtually indestructible, not to mention the light weight aspect!!!

(http://www.formula1-dictionary.net/Images/monocoque_red.gif)

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:02:14 PM
Here are drawings of the V.5.3 which is a DIF chassis layout.  This geometry reduced the frontal area by slightly over 1.5 sq.ft. total.  I also went with a single vertical tail stabilizer to help reduce frontal area.  I'm keeping the active aero wing even though there is a FA penalty because I believe the ability to add aero downforce is necessary to gain the greatest traction advantage without an added ballast penalty.  The exact location of the mid-wing will depend on the Cg which I've moved even further forward by rearranging the engine and other components.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:09:15 PM
Moving the driver compartment forward ahead of the front wheels affords a significant 23% FA reduction.  In the quest for record speeds that's the greatest benefit to be had with this powertrain combination.  I've also configured the cockpit to be detached from the rest of the chassis in the event of a crash by incorporating explosive bolt connections at the contact points.  A cockpit chute is added to deploy automatically via a lanyard cable should the compartment be ejected.

The two chassis sections index together with fixed dowel pins and pockets acting as the alignment for the frangible clamping bolts.  Would probably out a couple of springs in pockets between the two bulkhead posts to push the sections apart when the bolts were exploded.
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on July 28, 2019, 08:20:17 PM
Instead of explosive bolts & associated sensors why not just design in a weak point that will fracture under high unusual stress?

Regards, Neil  Tucson, AZ
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:21:24 PM
The steering mechanism worked out easier than I thought it would by using (2) 90 degree gear boxes hard mounted to the bulkheads with a center shaft connecting the two between the main chassis and the detachable driver compartment.  Hand levers for steering were added rather than a wheel as suggested by Tom B.  Most of the driver controls would be wired into the hand grips and triggers. One grip trigger would be the IC engine throttle and the other would be the reverse current braking on the wheel motors. The 2 chutes would be released by the protected switches on top of the grips.

There's more FA that can be saved in this DIF chassis layout by offsetting the steering wheels and tucking in the frame rails and body.  However, that narrows the track width again which as several have suggested is not a good thing for this vehicle.  Your thoughts?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:28:48 PM
Instead of explosive bolts & associated sensors why not just design in a weak point that will fracture under high unusual stress?

Regards, Neil  Tucson, AZ

Hi Neil,
That's was my intention in an earlier version where Eddie remarked about the weak point between the cage and back half of the chassis.  Here I decided to incorporate the bolts instead and trigger them with a 24v charge based on the driver's reaction.  I like the more positive ejection the EXbolts provide rather than some unknown stress point that may or may not release depending on the severity of a crash.  If it's going over or jumps up at speed I'd want the two halves to separate on command.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:43:40 PM
If anyone has a link to an accurate aerodynamic hp to speed calculator I'd appreciate a share.  I've looked at all I could find through Google and the results vary widely.  Do any of the calculators you've use correlate well to actual speeds of your car or bikes? I'm using the following inputs to base line this design:
Cg = .09
FA = 5.261
Weight = 4000
Speed = 600 mph

Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 28, 2019, 08:53:18 PM
Hi Terry,
From a complete novice AND vintage bike rider (  :dhorse: )!!!

Was looking at this frontal forest of tubes and your narrow vision slit area, surely less than 5 degree vision cone and a recipe for no side vision at all, important if you want to foresee in good time obstacles, pot holes, barrels, cones, or whatever else delimit the course 1 or 2 seconds in front of you @ 450mph!!!

Obviously, if you go forthwith with your front driver compartment, it will solve this issue at once!!!

Does some one higher up insist on so much tubing? If you slide to a rest it's useless, if you somersault, surely you want a bit of crumble availability to absorb some of the impacts and the G forces before they get to the driver???

More to the point, is carbon fiber still a no-no in LSR circles??? An F1 driver's cage is virtually indestructible, not to mention the light weight aspect!!!

(http://www.formula1-dictionary.net/Images/monocoque_red.gif)

Patrick

Hi Patrick,
Yes, V.5.2 has some vision issues due to the driver placement.  I've looked at an exposed driver canopy on a mid mounted cockpit in earlier versions but here I wanted to try a sweeping body geometry.  The DIF V.5.3 above eliminates the vision problem AND reduces the FA significantly so that's what we're going with for now.

The forest of tubes was incorporated in V.5.2 because I had so much weight forward of the steering wheels and needed the stiffness the extra tubes provided.  With V.5.3 I was able to move most of that weight behind the wheels and the driver section is a self contained structure that is well supported at the parting bulkheads. 

Use of a carbon fiber tub is obviously a desirable option in terms of stiffness and weight savings.  Several LSR vehicles have used one with success.  The Ohio State BB3 electric car used an IRL tub as the basis of their chassis design rather than build their own because the crash data was already known and the cost was in their budget.  This project is based on a tube chassis because that's what I know and have experience with.  Cost is also a factor but overall width is too which comes into play for an IRL cockpit which is an unknown to me.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on July 29, 2019, 11:29:58 AM
Thanks Terry...

Four years back, I was planning a partially streamlined bike, me lying down like you but not enclosed:

(http://www.landracing.com/forum/index.php?action=dlattach;topic=17792.0;attach=62389;image)

And my engine, supercharged methanol fed 900 side valve Vee Twin lying where your front wheels are.

Since I'm in Great Britain, I needed the bike able to part in two for ease of transport...

After some back and fro with the SCTA tech boys, we agreed a partition design with back to back full bulkheads, each steel and 1/2" thick. about 10 bolts and 6 pin locators...

When the quotes arrived to cut and machine all that, I decided to stick with std motorcycles until I win the lottery!!!!!!!!!!!!!!

All that to say your 5 holding bolts look a touch lightweight to me with so much cantilever up front

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on July 29, 2019, 12:55:19 PM
Just a comment, and I have no proof of the theory, but I've always felt that when a driver is placed that far forward he/she has less feel for the yaw position of the car and this could prove disastrous. Lights and/or alarms may in theory help with this but under the pressure of making a run it's very possible that the driver wouldn't react to such in time.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: Stainless1 on July 29, 2019, 01:54:07 PM
I agree w/PJ... I think sitting in front of the steerable wheels  is asking for issues.  You will loose the "butt feel" of the car.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 04:45:32 PM
Just a comment, and I have no proof of the theory, but I've always felt that when a driver is placed that far forward he/she has less feel for the yaw position of the car and this could prove disastrous. Lights and/or alarms may in theory help with this but under the pressure of making a run it's very possible that the driver wouldn't react to such in time.

Pete
Quote
I agree w/PJ... I think sitting in front of the steerable wheels  is asking for issues.  You will loose the "butt feel" of the car.

Thanks for your comments guys.  I've received several comments like these concerned about the lack of back feed of a vehicle's yaw attitude from a DIF position.  A little research confirms the condition and how it's been addressed in aeronautics since the Wright brothers with yaw or slip indicators.  Gliders are especially susceptible to the detrimental effects of increased drag when yaw or slip conditions are encountered in flight. The widespread use across all types of airplanes (gliders to fighter jets) of a simple mechanical device called a "Yaw String" (it was invented by Wilbur Wright) allows air pilots to see yaw movement in real time and react quickly to counteract the effect by dialing in more opposite rudder as a control.

Naturally LSR vehicles will experience more disastrous outcomes when late reactions to yaw conditions result in lost of control and crashes.  A Yaw String should in practice work equally well for a DIF streamliner as it does for large percentages of air pilots that rely on them today.

So, what is a Yaw String?  Its nothing more than a piece of string or yarn taped to the exterior of the canopy or fastened forward of the canopy in the pilots line of sight.  As the tail of the craft moves left or right from zero yaw, the string will instantly follow suit indicating the change in direction of air flow over the nose of the craft.  Because the string is in the pilot's line of sight s/he will see it move without taking his/her eyes off the path ahead.  Instinctively, as with DIM or rear cockpit positions, minute steering corrections will be made to counter yaw movements to keep the vehicle tracking as straight and true as humanly possible.
https://www.youtube.com/watch?v=A1dU63d7HHw (https://www.youtube.com/watch?v=A1dU63d7HHw)

If this should be the case, which I have no reason to believe otherwise considering it's long history of use in aeronautics,  I consider the aerodynamic and visual advantages of DIF chassis geometry outweigh the risks where a yaw string is put to use on the vehicle.  Does anyone know of a DIF streamliner that's used a yaw string successfully?  How about unsuccessfully?  I'd be interested to read about their experiences.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 04:58:53 PM
Thanks Terry...

your 5 holding bolts look a touch lightweight to me with so much cantilever up front

Patrick

Hi Patrick,
Thanks for sharing that experience.  You could be right about a need for more connection points to secure the cantilevered front chassis section.  Should we get to the point in the project where a structural review of the chassis design is warranted, we'll rely on an engineer's recommendations to finalize drawings before construction begins.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on July 29, 2019, 05:35:33 PM
It's not clear to me that a breakaway cockpit is safer in the LSR context.  I can see arguments for both sides of the question. 
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on July 29, 2019, 06:30:06 PM
Terry:

I think in this case we're dealing with the real world as opposed to theory. While a yaw string may work with an aircraft, even a high speed one, there is a lot more space and time between the aircraft and the ground than there is between a lsr vehicle and the ground. When something does go sideways and the adrenaline does start to flow even heavier is the driver going to concentrate on a piece of string or where he's going? The Wright brothers were travelling at a little less than 400 mph.  :-D :-D :-D

The driver of a vehicle is very slow to react to instrumentation as compared to what he can see around him and will probably look right through a close up piece of string to the ground he is about to cover at very high speeds, whether in a straight line or tumbling.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on July 29, 2019, 07:21:43 PM
Further to Peter's comments..
Yaw in an aircraft is of little consequence--not so in LSR.
When landing in a cross wind does the pilot pay attention to the ?yaw string? or the world around him?
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on July 29, 2019, 07:53:54 PM
Re: "Yaw String"

Terry, I became familiar with a yaw string when I was taking glider lessons in Babenhausen, Germany back in '62. The Babenhausen Aero Klub flight instructor was a WW II Messerschmidt fighter pilot. The club trainer was a 2-place glider with him sitting in the rear and me sitting ahead of him. The first few flights were fun even though the English/German language was a real problem. On one flight he wanted to demonstrate how to settle the glider for a landing even from a too- high approach to the field, a large open area adjacent to the woods.We flew for a short time and he brought the plane in on a very high approach over the woods when he suddenly kicked it into a very large yaw angle. The yaw string looked almost sideways and we dropped like a rock until the altitude was a normal approach and he straightened out and landed. That unannounced maneuver scared the crap out of me.  I sure never forgot that yaw string!

Regards, Neil  Tucson, AZ
Title: Re: Simspeed UWD LSR Design Project
Post by: jl222 on July 29, 2019, 08:34:41 PM
If anyone has a link to an accurate aerodynamic hp to speed calculator I'd appreciate a share.  I've looked at all I could find through Google and the results vary widely.  Do any of the calculators you've use correlate well to actual speeds of your car or bikes? I'm using the following inputs to base line this design:
Cg = .09
FA = 5.261
Weight = 4000
Speed = 600 mph

Thanks... Terry

  I have a program called Bonneville Pro by Racing Secrets a drag race results program modified for Bville. Pretty accurate except for acceleration rates '' to quick'' chart to put in cd, frontal area, weight,
tire width, gear ratio, tire roll out, and hp.  Gives a result chart with time, rpm distance and mph. Also wheelspin if to much hp for wheel width. Needs a downforce in put. Maybe newer versions have it.
 
 I  put all that data from Summer Brother's streamliner and it came out on the money.
 425 mph with 2400 hp.

  So unless your streamliner is way more aero you're going to need a lot more hp than 2400 to go 600 mph.

                    JL222

             
Title: Re: Simspeed UWD LSR Design Project
Post by: desotoman on July 29, 2019, 09:52:05 PM
Terry,

Please listen to Pete, Stainless and Interested Observer about the Yaw String.

Remember the air is fluid, the ground is not.

If you really would like a nice long type of Yaw String with lots of seat feel,
place the drivers compartment in the rear of the vehicle. Then the length of
the car is your Yaw String. Just a suggestion.

Tom G.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 10:50:08 PM
I've revised the steering assembly from an upper to lower spindle position per recommendations from Tom B.  Got rid of the right angle gear boxes and added double shear mounts to most of the linkage connections.  I also changed the camber back to zero degrees to accommodate flat plane mounting of the steering.  Not sure if that's suitable but I've read where others are using zero camber with zero scrub radius which this design has.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 10:57:05 PM
It's not clear to me that a breakaway cockpit is safer in the LSR context.  I can see arguments for both sides of the question.

Hi Tortoise,
The only reason I'd think the break away cockpit is any safer is deployment of a dedicated chute acting on a lighter total mass once the main chassis and drive components are separated.  Secondly I guess is the reduced risk of fire as fuels and oils are also separated.  Either way its a risky proposition with a crash of any type.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 11:16:24 PM
Terry:

I think in this case we're dealing with the real world as opposed to theory. While a yaw string may work with an aircraft, even a high speed one, there is a lot more space and time between the aircraft and the ground than there is between a lsr vehicle and the ground. When something does go sideways and the adrenaline does start to flow even heavier is the driver going to concentrate on a piece of string or where he's going? The Wright brothers were travelling at a little less than 400 mph.  :-D :-D :-D

The driver of a vehicle is very slow to react to instrumentation as compared to what he can see around him and will probably look right through a close up piece of string to the ground he is about to cover at very high speeds, whether in a straight line or tumbling.

Pete
Hi Pete,
 :-P No doubt about the Wright bros speed...LOL.  I feel whether the driver is DIR seeing the yaw change between his position and the nose of the car or DIF reacting to the change in air flow as indicated by a yaw string he's reacting to what he sees in front of him based on the sensitivity of how the change in position is presented to him.  Altitude or distance to the ground as experienced in flight isn't an issue in my opinion. 

Based on what I now understand about a yaw string, meaning how it works to indicate what's happening at the rear of the car in minute detail, this indicates to me its a highly sensitive instrument a DIF driver can use to react quickly to yaw conditions in an attempt to keep the car under control.  Is that as good as a DIR driver experiences?  I don't know of course because I have no seat time fore or aft...but does anyone here who does know that it's not?  Like you I've heard driving from the rear is safer and affords greater control but do we know of anyone whose driven a DIF car using a yaw string?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 11:28:08 PM
Further to Peter's comments..
Yaw in an aircraft is of little consequence--not so in LSR.
When landing in a cross wind does the pilot pay attention to the ?yaw string? or the world around him?

Hi IO,
I'm not trying to create a direct analogy between the two although that's what my comments sound like.  All I'm saying is that a yaw string in a DIF application would act as a useful indicator of changes in attitude at the rear of the car that the driver could react to in lieu of the seat of the pants feel from a DIR or DIM driving position.  In those positions (I'm supposing) what the driver feels is largely based on what he sees in the change in relationship between his position, the nose of the car, and the horizion out his canopy.  In the DIF car the angle of change is largely unknown due to the driver's position relative to the nose and horizon but a yaw string offers real time info of those conditions he can use just as quickly and effectively as a DIR driver would once he understands the value of what he's seeing through his canopy.  All of that is supposition on my part of course but its based on the reality of how a yaw string works and why.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 11:35:33 PM
Re: "Yaw String"

Terry, I became familiar with a yaw string when I was taking glider lessons in Babenhausen, Germany back in '62. The Babenhausen Aero Klub flight instructor was a WW II Messerschmidt fighter pilot. The club trainer was a 2-place glider with him sitting in the rear and me sitting ahead of him. The first few flights were fun even though the English/German language was a real problem. On one flight he wanted to demonstrate how to settle the glider for a landing even from a too- high approach to the field, a large open area adjacent to the woods.We flew for a short time and he brought the plane in on a very high approach over the woods when he suddenly kicked it into a very large yaw angle. The yaw string looked almost sideways and we dropped like a rock until the altitude was a normal approach and he straightened out and landed. That unannounced maneuver scared the crap out of me.  I sure never forgot that yaw string!

Regards, Neil  Tucson, AZ

HI Niel...good story.  Any indicator is only as good as the pilot/driver who understand them and knows how to apply the info to the performance of the vehicle he's flying/driving.  A yaw string in this application gives instantaneous information to the driver of the nose/tail relationship relative to the intended path as indicated by the change in airflow around the nose.  Whether or not that's as useful as what a DIR driver sees and experiences from those positions is unknown to me at this time but the logic of how a yaw string functions is not lost on me.  I'm interested in learning more of real world experiences from someone whose use a yaw string from a DIF ride.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 11:43:58 PM
If anyone has a link to an accurate aerodynamic hp to speed calculator I'd appreciate a share.  I've looked at all I could find through Google and the results vary widely.  Do any of the calculators you've use correlate well to actual speeds of your car or bikes? I'm using the following inputs to base line this design:
Cg = .09
FA = 5.261
Weight = 4000
Speed = 600 mph

Thanks... Terry

Hi
  I have a program called Bonneville Pro by Racing Secrets a drag race results program modified for Bville. Pretty accurate except for acceleration rates '' to quick'' chart to put in cd, frontal area, weight,
tire width, gear ratio, tire roll out, and hp.  Gives a result chart with time, rpm distance and mph. Also wheelspin if to much hp for wheel width. Needs a downforce in put. Maybe newer versions have it.
 
 I  put all that data from Summer Brother's streamliner and it came out on the money.
 425 mph with 2400 hp.

  So unless your streamliner is way more aero you're going to need a lot more hp than 2400 to go 600 mph.

                    JL222

           
Hi JL222,

Good to know!  Here's additional data of this design based on your comments above:

Tire width: 6"
Gear Ratio: 1:1
Wheel roll out: 73.7" or 23.5" diameter
HP is the unknown I'm looking to identify based on these other parameter.  Can you calculate HP from that all that info?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 29, 2019, 11:50:37 PM
Terry,

Please listen to Pete, Stainless and Interested Observer about the Yaw String.

Remember the air is fluid, the ground is not.

If you really would like a nice long type of Yaw String with lots of seat feel,
place the drivers compartment in the rear of the vehicle. Then the length of
the car is your Yaw String. Just a suggestion.

Tom G.

Hi Tom G.,
Thanks for the tip... Your comparison is notable in relation to my argument.  The reason I'm leaning to the DIF geometry is the 22% reduction in frontal area for the current design when compared to previous designs I've worked on with DIM and DIR positions.  If in fact use of a yaw string gives useful car attitude info to the DIF driver then applying that to reduce the FA is a no brainer to me.  It has to be proven of course so I'm remaining open to the proposition until I learn definitively from someone that's tried it that its not.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on July 30, 2019, 01:18:39 AM
I believe that there was a streamliner that had a sort of a pole extending from its nose strait forward so the driver could sight down it and know if things were getting out of shape.

I didn't see it in person but read about it.
Does anyone else remember this?

  Don
Title: Re: Simspeed UWD LSR Design Project
Post by: RidgeRunner on July 30, 2019, 05:45:21 AM
     Yes.  Athol Graham's "City of Salt Lake" when rebuilt after his fatal crash.  There has been much discussion since on exactly what happened but in my opinion the driver's position, while maybe not the total cause, certainly was a major contributing factor.

     First time my new '71 Ford van got loose in the snow on me I was almost sideways before I realized what was happening.  This after 10 winters of driving cars and trucks with more conventional seating locations.  I realized real quick that when sitting almost on top of the pivot point a lot of "natural feel" is lost.

     FWIW, when my buddy took his tank bodied lakester - driver's position at the very front - to Speedweek in '72 the inspector strongly suggested installing some kind of vertical indicator for reference out in front of the driver's line of vision.  He said he had lost a very good friend and something like that might have helped prevent that loss.

      For sure an area worthy of serious consideration during the design phase of any LSR car.

                         Ed

                   

     
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on July 30, 2019, 08:10:43 AM
1) Yaw string - forget it.  It indicates airflow direction, not vehicle/terrain orientation.
2) What keeps the orange front axle housing from itself rotating and allowing uncommanded steering input?
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on July 30, 2019, 11:01:34 AM
Back in the 1930s, the two dominant Grand Prix cars were Mercedes-Benz and Auto-Union. The Mercedes had a conventional layout while the Auto-Union placed the driver much farther forward. The consensus was that the A-U cars were more difficult to drive because that driver's position gave him less feedback about the car's yaw angle. Ultimately, Bernd Rosemeyer was killed on the Darmstadt autobahn during a speed record attempt

Regards, Neil  Tucson, AZ
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on July 30, 2019, 11:41:40 AM
     Yes.  Athol Graham's "City of Salt Lake" when rebuilt after his fatal crash.  There has been much discussion since on exactly what happened but in my opinion the driver's position, while maybe not the total cause, certainly was a major contributing factor.

                         Ed


Thanks Ed, but not the car I was thinking of.

What I think I remember was the race officials not letting this car run until they devised an indicator of sorts.

Then again it could have been a dream.   :-D

  Don
                   

     
Title: Re: Simspeed UWD LSR Design Project
Post by: Sumner on July 30, 2019, 01:15:39 PM
..
     First time my new '71 Ford van got loose in the snow on me I was almost sideways before I realized what was happening.  This after 10 winters of driving cars and trucks with more conventional seating locations.  I realized real quick that when sitting almost on top of the pivot point a lot of "natural feel" is lost. ...

Same with a '68 chevy van in Wyoming.  It could do 360's in a heartbeat on an icy road.  Never had the same problem with any other vehicle in the same conditions.

A good driver, and you are going to need a great one if you are planning on running even over 400, is going to feel what is going on in 'his butt' way before he is going to visually see it.  This is true at even regular highway speeds.  Next winter take your car out and push it in snowy conditions with a yaw string and see if you feel what is going on body wise vs. sight wise first and which allows you to compensate.

I feel a lot of people don't have any idea how much a car has to be driven on the salt.  Straight line on a flat surface, surly can't be hard to drive right?  But, watch in-car videos and see how much people's hands move and the wheel moves on any car that can over power the salt.  You are reacting way faster than you could by watching something visually and then correcting.

Moving the driver in front of the front wheels undoubtedly offers aero advantages but if the car can't be driven safely what is the point.  A driver that is sitting very closely behind the front wheels is in a tougher driving situation vs. one sitting further back.

================================

With the Summer Brother's car if the figures are accurate it would of taken them 3900 HP to run 500 (probably about what the Turbinator used to run 500).  To run 600 they would of needed 6700 HP.  You don't only need the HP but the parts that won't break using that much HP and a track long enough to get it to the desired speed.  Pretty unbelievable that the Turbinator was able to have a 503 exit speed in 5 miles and they have been doing this for a couple family generations now  :-D.

Sumner

Title: Re: Simspeed UWD LSR Design Project
Post by: RidgeRunner on July 30, 2019, 01:31:03 PM
     Might not be a dream Don, I also think I remember a "lawn dart" style with a single indicator on the nose in more recent years, red in color?  Couldn't remember any details so didn't mention it.

     Then again could we both have been on the same barley pop recipe at the same time once?   :cheers:

                   Ed
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 01:54:11 PM
1) Yaw string - forget it.  It indicates airflow direction, not vehicle/terrain orientation.
2) What keeps the orange front axle housing from itself rotating and allowing uncommanded steering input?

IO,
1) Changes in airflow direction along the nose that diverge from the intended straight line path are in fact a primary indicator of changes in vehicle/terrain orientation.
2) The A-frames limited by shock absorber travel which in this case is roughly 2" total.
Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 02:01:18 PM
Back in the 1930s, the two dominant Grand Prix cars were Mercedes-Benz and Auto-Union. The Mercedes had a conventional layout while the Auto-Union placed the driver much farther forward. The consensus was that the A-U cars were more difficult to drive because that driver's position gave him less feedback about the car's yaw angle. Ultimately, Bernd Rosemeyer was killed on the Darmstadt autobahn during a speed record attempt

Regards, Neil  Tucson, AZ
Hi Niel,
I certainly agree with you and others that lack of yaw feedback to the driver in a DIF position makes safely controlling the vehicle at speed much more difficult.  I'm not attempting to say otherwise.  All I'm proposing is that if a yaw indicator of sufficient fidelity is available to the DIF driver, then logically he should be able to react just as quickly to input corrective steering control.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 02:07:44 PM
Next winter take your car out and push it in snowy conditions with a yaw string and see if you feel what is going on body wise vs. sight wise first and which allows you to compensate.

I feel a lot of people don't have any idea how much a car has to be driven on the salt.  Straight line on a flat surface, surly can't be hard to drive right?  But, watch in-car videos and see how much people's hands move and the wheel moves on any car that can over power the salt.  You are reacting way faster than you could by watching something visually and then correcting.

Moving the driver in front of the front wheels undoubtedly offers aero advantages but if the car can't be driven safely what is the point.  A driver that is sitting very closely behind the front wheels is in a tougher driving situation vs. one sitting further back.

Sumner

Hi Sumner,
Good suggestion about testing the effectiveness of a yaw string in icy highway conditions.  Not sure if its applicable along a relatively flat car windshield.  I'd think a yaw string would work best on a narrow and tapered cockpit canopy as found in gliders, fighter jets, and streamliners.  As stated previously, I definitely agree that a forward driver position is harder to drive all things being equal. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 02:13:20 PM
I believe that there was a streamliner that had a sort of a pole extending from its nose strait forward so the driver could sight down it and know if things were getting out of shape.

I didn't see it in person but read about it.
Does anyone else remember this?

  Don

Hi Don,
I can see how a pole extended from the nose would offer a indication of change in the straight forward direction.  To me, a yaw string serves the same purpose much more practically applied.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: TrickyDicky on July 30, 2019, 02:27:56 PM
How about this one for DIF?
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on July 30, 2019, 02:49:45 PM
Quote
1) Changes in airflow direction along the nose that diverge from the intended straight line path are in fact a primary indicator of changes in vehicle/terrain orientation.
  Yeah, until there is a side wind or gust.  You can bet the driver is going to be focused on the far horizon, not some string two feet in front of him.

Quote
2) The A-frames limited by shock absorber travel which in this case is roughly 2" total.
The point was in reference to steering, i.e., rotation about the vertical axis.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 03:20:05 PM
How about this one for DIF?

HA!! I guess roll cages were considered just excess weight back then Tricky.  Notice the 4 wheel drive... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on July 30, 2019, 03:37:36 PM
How about this one for DIF?

That driver is going to be the first to the scene of the accident!

Regards, Neil  Tucson, AZ
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 03:39:31 PM
Quote
1) Changes in airflow direction along the nose that diverge from the intended straight line path are in fact a primary indicator of changes in vehicle/terrain orientation.
  Yeah, until there is a side wind or gust.  You can bet the driver is going to be focused on the far horizon, not some string two feet in front of him.

Quote
2) The A-frames limited by shock absorber travel which in this case is roughly 2" total.
The point was in reference to steering, i.e., rotation about the vertical axis.

I'd agree the string two feet in front of him won't be his point of focus IO; but that doesn't mean its movement to the left or right won't go unnoticed and influence his steering input just as if it were.  What is it about the slow moving far horizon that provides minute influence on a driver's steering decision making do you think?  Would it not seem than a highly sensitive moving instrument directly in the driver's field of vision would more directly influence his judgement even if that wasn't his immediate point of focus?  It would to me so that's my point for why I think it would be effective.

I guess I'm missing your point about the rotational axis IO.  The horizontal pivot point of the tie rod is mounted to the orange steering knuckle.  The two short links running forward from the swivel plates to the crossbar uprights pivot on the vertical axis along the center of the connecting heim joints at the crossbar uprights. To that extent the steering assembly pivots (travels) with the vertical movement of the knuckle.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 30, 2019, 03:41:16 PM
How about this one for DIF?

That driver is going to be the first to the scene of the accident!

Regards, Neil  Tucson, AZ

I'd be interested to know what the outcome of their LSR efforts was.  Did it set a record?  How fast did it go?  Did it crash and burn?  Anyone know?
Title: Re: Simspeed UWD LSR Design Project
Post by: TD on July 30, 2019, 04:22:32 PM
Quote
I'd be interested to know what the outcome of their LSR efforts was.  Did it set a record?  How fast did it go?  Did it crash and burn?  Anyone know?

Good one TrickyDicky!   See also the first(?) Wingfoot Express.

I'll spare everyone else the bother and tell you that's John Cobb sitting in the Railton Special, later the Railton Mobil Special.

Cobb held the unlimited LSR, briefly, in September 1938 at 353 MPH, then again between August 1939 and September 1947 at 369 MPH.  In September 1947 Cobb raised the record to 394, including one run at 403.  Breedlove, Donald Campbell, and the Summers Brothers went faster, using different means of propulsion, in 1963, 1964, and 1965, respectively.

Surprised no one has mentioned a yaw sensor, such as might be used in any modern production car; perhaps the yaw rates might be higher than one might expect in a production vehicle, making such a sensor unsuitable.  What to do with the output would be the next question.

Thanks for the interesting thread!



Title: Re: Simspeed UWD LSR Design Project
Post by: TrickyDicky on July 30, 2019, 04:37:17 PM
Quote
I'd be interested to know what the outcome of their LSR efforts was.  Did it set a record?  How fast did it go?  Did it crash and burn?  Anyone know?

Good one TrickyDicky!   See also the first(?) Wingfoot Express.

....

Cobb held the unlimited LSR, briefly, in September 1938 at 353 MPH, then again between August 1939 and September 1947 at 369 MPH.  In September 1947 Cobb raised the record to 394, including one run at 403. 


Yes, first over 400 mph, 13 years before Mickey Thompson.

As far as I know the Railton Special never crashed.

John Cobb died trying to break the World Water Speed Record. Much more dangerous ...
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on July 30, 2019, 04:42:28 PM
Let's try this one more time. I'm not trying to be obstinate but a driver can't watch a string right outside the windshield and at the same time concentrate on keeping the missile between the flags at great speed. Things are happening too fast! At the same time, don't reject "butt feel" when it comes to car control. By the time you feel yaw in such a forward cockpit you'll already be out of control and way too far gone to correct. The same goes for the string.

Safety has always been a huge thing with any race car I've built or prepared and I'm really proud of the safety record I've maintained. I just can't let this go.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: John Burk on July 30, 2019, 04:55:12 PM
Terry , frontal area may be less important than a person would think . Knowledgeable people have said here that most (80%?) of the drag of streamlined cars is skin friction .
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on July 30, 2019, 05:08:38 PM
I remember years ago seeing a roadster that had a 1-inch pointed pole about 5 feet long sticking out the crankhole of the radiator shell.  The driver could not see it.  I asked what that was all about. "Just to trip people walking in front of us without watching where they were going."  Probably didn't help stability or driving at all.
Title: Re: Simspeed UWD LSR Design Project
Post by: 4-barrel Mike on July 30, 2019, 05:33:41 PM
Was it a white SR?

Mike
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on July 30, 2019, 06:32:50 PM
The minimal separation of the Heim joints at the forward end  of the upper A-arm effectively constitute a pivot point that, in conjunction with the Heim on the aft end of the lower A-arm, would allow the ?steering knuckle? to rotate about the connecting axis, likely producing unwanted steering effects and probably a god-awful speed wobble.
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on July 30, 2019, 08:42:07 PM
Terry:

This continues to be a really interesting thread because there's lots of interesting input being considered in so many different ways. A project such as this needs people who may tend to err on the conservative side and probably always will. There are also the dreamers who come up with the really great ideas which may need at times to be toned down or refined for practical application.

Keep up the good work coordinating this whole thing. We finally have a dreamer who's fun to work with.  :cheers: :cheers: :cheers:

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: SPARKY on July 30, 2019, 10:49:09 PM
 Yeah, until there is a side wind or gust.  You can bet the driver is going to be focused on the far horizon, not some string two feet in front of him.


If you had ever flown a glider much you would not make that statement

I have used yaw strings on the salt flat  it registers while you are looking at floating mountain
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on July 31, 2019, 09:34:53 AM
I'm with Peter Jack as far as where to look out when riding or driving...

On a bike, I look as far forward as possible... And the faster the furthest...

In a car, same!!!

For anything that's near, I just rely, like the birds and my cat, on movement or change of status, that's what peripheral vision, no matter how blurred, is for...

Same for butt feel, that's the only way, added with sense of balance in your ears and spacial geometry.

Lots of guys/gals don't have it, them the ones that will crash if they try too hard without these essential feedback loops...

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Seldom Seen Slim on July 31, 2019, 09:46:29 AM
As I had it put during an on-track bike school:

Look down the road/course at where you're going.  It's too late to do anything about where you are right now - you should have seen it coming while you were looking ahead.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 10:34:32 PM
I'll spare everyone else the bother and tell you that's John Cobb sitting in the Railton Special, later the Railton Mobil Special.

Cobb held the unlimited LSR, briefly, in September 1938 at 353 MPH, then again between August 1939 and September 1947 at 369 MPH.  In September 1947 Cobb raised the record to 394, including one run at 403.  Breedlove, Donald Campbell, and the Summers Brothers went faster, using different means of propulsion, in 1963, 1964, and 1965, respectively.

Thanks for the interesting thread!

Thank you TD for this info.  I've read through the coverage and videos of Cobb and Campbell's LSR efforts and I'm frankly amazed at the speeds they achieved given the technology of their time.  Both their cars use a DIF layout without a stabilizer fin and didn't seem to suffer from a lack of control until Campbell's 350 mph crash due to what he described as soft salt conditions.  Addition of a fin to the Bluebird rebuild helped him to capture a record two years later.  Any ideas why the DIF of these two cars didn't appear to affect driver control?  Thank... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 10:36:49 PM
Yes, first over 400 mph, 13 years before Mickey Thompson.

As far as I know the Railton Special never crashed.

John Cobb died trying to break the World Water Speed Record. Much more dangerous ...
Quite the accomplishment I'd say Tricky. Thanks for sharing... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 10:43:53 PM
By the time you feel yaw in such a forward cockpit you'll already be out of control and way too far gone to correct. The same goes for the string.

Pete
I agree with your statement Pete...if a DIF driver is basing his steering decisions on "feel" alone then he is definitely at a disadvantage to a DIR driver.  I have to disagree about the string being the same...logically, the string is a real time indicator of yaw attitude change and its usefulness depends on the drivers ability to incorporate the info its generating in real time along with all the other visual and sensory clues he's experiencing at the front of the car.  Cobb and Campbell proved the DIF position can be used successfully.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 10:50:28 PM
Terry , frontal area may be less important than a person would think . Knowledgeable people have said here that most (80%?) of the drag of streamlined cars is skin friction .

Hi John,
I have no reason to believe skin friction doesn't generate drag as you say.  Whether or not a short car with larger frontal area generates less total drag than a long car with less frontal area can only be determined through comparative testing.  We'd probably agree a short car with less frontal area would be the best scenario overall but in this project example that's just not an option given the space taken up by the powerplants and supporting systems.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 11:05:04 PM
The minimal separation of the Heim joints at the forward end  of the upper A-arm effectively constitute a pivot point that, in conjunction with the Heim on the aft end of the lower A-arm, would allow the ?steering knuckle? to rotate about the connecting axis, likely producing unwanted steering effects and probably a god-awful speed wobble.

Hi IO,
Sorry but your description of the rigidity of the front suspension geometry isn't accurate in my opinion.  The a-frames are each triangulated in the shown layout.  There will be no side to side movement through the heim joints other than the clearances allowed to exists between the ball centers and the mounting flanges.  As far as rotating about the connecting axis that's just suspension travel through whatever range of motion the shocks and bump stops are preset to allow.  You're supposed "god-awful" speed wobble is based on what exactly? 

Let's open this up to everyone's determination of your claims.  Who agrees with IO's take on the front suspension as shown and why?  If I'm wrong I'd surely like to know who thinks IO's take is correct and why. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 11:10:07 PM
Terry:

This continues to be a really interesting thread because there's lots of interesting input being considered in so many different ways. A project such as this needs people who may tend to err on the conservative side and probably always will. There are also the dreamers who come up with the really great ideas which may need at times to be toned down or refined for practical application.

Keep up the good work coordinating this whole thing. We finally have a dreamer who's fun to work with.  :cheers: :cheers: :cheers:

Pete

Thanks for your encouragement Pete.  I'm counting on getting honest opinions and constructive criticism from folks like you whose experiences and success far exceed my own.  I won't hesitate to argue my own positions but I'm certainly open to being educated about things I don't completely understand and altering my views accordingly.
 Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 11:16:57 PM
Yeah, until there is a side wind or gust.  You can bet the driver is going to be focused on the far horizon, not some string two feet in front of him.


If you had ever flown a glider much you would not make that statement

I have used yaw strings on the salt flat  it registers while you are looking at floating mountain
Thanks Sparky...that's the expectation my arguments are based on.  I'm thinking that subconsciously the string movement will translate into reactive adjustments on the steering controls by the driver.  A side wind or gust will no doubt impact the car but in doing so the string will show a corresponding yaw movement that indicates the proper corrective action by the driver.  Thanks for helping to confirm an experience that I've been hoping to find... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 11:25:03 PM

For anything that's near, I just rely, like the birds and my cat, on movement or change of status, that's what peripheral vision, no matter how blurred, is for...

Same for butt feel, that's the only way, added with sense of balance in your ears and spacial geometry.

Patrick

Hi Patrick,
I quite agree with your assessment as a whole.  I believe it is the combination of all sensory inputs that gives a driver what s/he needs to know to make the best driving decisions.  I also agree that not everyone computes those inputs equally or reacts with speed and acuity for best results.  Some people are always better than others at similar challenges.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on July 31, 2019, 11:39:00 PM
As I had it put during an on-track bike school:

Look down the road/course at where you're going.  It's too late to do anything about where you are right now - you should have seen it coming while you were looking ahead.

My point exactly Slim.  Where we'll be in the next instant ahead depends on how we reacted to whatever sensory input that was available in the last instant past.  How we position ourselves to receive and subsequently interpret inputs as they arrive, and the fidelity of those inputs on a corresponding value scale, forms the entire basis of our coordinated response.  Too little or inaccurate info and we are likely to make bad decisions. Rejecting good info because we're either unwilling to accept or ill informed about it's usefulness can also lead to bad decisions.  Examining our input options equally and fairly offers the best chance that the inputs we need in any give operating scenario will be there when we need them for the best decisions we as individuals are capable of making. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: RidgeRunner on August 01, 2019, 07:04:54 AM
I'll spare everyone else the bother and tell you that's John Cobb sitting in the Railton Special, later the Railton Mobil Special.

Cobb held the unlimited LSR, briefly, in September 1938 at 353 MPH, then again between August 1939 and September 1947 at 369 MPH.  In September 1947 Cobb raised the record to 394, including one run at 403.  Breedlove, Donald Campbell, and the Summers Brothers went faster, using different means of propulsion, in 1963, 1964, and 1965, respectively.

Thanks for the interesting thread!

Thank you TD for this info.  I've read through the coverage and videos of Cobb and Campbell's LSR efforts and I'm frankly amazed at the speeds they achieved given the technology of their time.  Both their cars use a DIF layout without a stabilizer fin and didn't seem to suffer from a lack of control until Campbell's 350 mph crash due to what he described as soft salt conditions.  Addition of a fin to the Bluebird rebuild helped him to capture a record two years later.  Any ideas why the DIF of these two cars didn't appear to affect driver control?  Thank... Terry

     I have followed LSR since the late 50's and finally getting to experience being there in '71 & '72,  then again in '08.  From my actual observations, seeing pictures and reading about conditions before and since, I'll say that the  salt surface conditions have changed DRASTICALLY since the time of Cobb's, Campbell's, Breedloves's, Summer's runs and those of others back then.  Current conditions should be a MAJOR factor in any present attempt equations.

    I've found this a very interesting project to follow, stay with it and all my best for your success!

                    Ed

     
Title: Re: Simspeed UWD LSR Design Project
Post by: TD on August 01, 2019, 07:27:51 AM
Quote

Thank you TD for this info.  I've read through the coverage and videos of Cobb and Campbell's LSR efforts and I'm frankly amazed at the speeds they achieved given the technology of their time.  Both their cars use a DIF layout without a stabilizer fin and didn't seem to suffer from a lack of control until Campbell's 350 mph crash due to what he described as soft salt conditions.  Addition of a fin to the Bluebird rebuild helped him to capture a record two years later.  Any ideas why the DIF of these two cars didn't appear to affect driver control?

No idea really.  Both cars featured relatively wide track and all-wheel drive, which might have made them somewhat easier to drive.
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on August 01, 2019, 07:55:33 AM
The potential problem I am describing has nothing to do with suspension travel or side-to-side movement at the Heims.  It has to do with the limited resistance to rotation about the axis between the upper and lower Heims at the narrow ends of the A-arms.  Given mechanical clearances and elasticity, the narrow spacing of the upper Heim pair cannot be considered a rigid connection in a steering rotation sense, but rather just an upper pivot point.  The front wheel assembly is effectively mounted on a kingpin with dubious steering rotation stiffness.
Title: Re: Simspeed UWD LSR Design Project
Post by: SPARKY on August 01, 2019, 12:29:38 PM
my experience is you are looking past/through the yaw string-- your visual  image input changes on/of the horizon change was definitely easier/sooner to pick --operates much like a range when on the water.But you need fixed objects on ones horizon
Title: Re: Simspeed UWD LSR Design Project
Post by: Rex Schimmer on August 01, 2019, 01:13:57 PM
There is a new streamliner that will probably be able to provide some input on this question. I am expecting this car to be very fast at Speed Week.

Rex
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 01, 2019, 02:23:35 PM

     I have followed LSR since the late 50's and finally getting to experience being there in '71 & '72,  then again in '08.  From my actual observations, seeing pictures and reading about conditions before and since, I'll say that the  salt surface conditions have changed DRASTICALLY since the time of Cobb's, Campbell's, Breedloves's, Summer's runs and those of others back then.  Current conditions should be a MAJOR factor in any present attempt equations.

    I've found this a very interesting project to follow, stay with it and all my best for your success!

                    Ed   
Hi Ed,
Thanks for your encouragement.  I'm sure you're assessment of the salt and its influence on today's racers is correct.  It's a real shame that the salt flats have been allowed to deteriorate as they have.  The state should have stepped in earlier to help preserve what I consider a national treasure.  Where are the eco-activitist when we need them?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 01, 2019, 02:27:11 PM
There is a new streamliner that will probably be able to provide some input on this question. I am expecting this car to be very fast at Speed Week.

Rex
That's certainly an interesting design Rex.  I was quite intrigued the first time I saw it.  Do you know what the drive train consist of?  Are there any links to the builder?  What's the name so I can look to see what I can find out about it?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 01, 2019, 05:08:18 PM
The potential problem I am describing has nothing to do with suspension travel or side-to-side movement at the Heims.  It has to do with the limited resistance to rotation about the axis between the upper and lower Heims at the narrow ends of the A-arms.  Given mechanical clearances and elasticity, the narrow spacing of the upper Heim pair cannot be considered a rigid connection in a steering rotation sense, but rather just an upper pivot point.  The front wheel assembly is effectively mounted on a kingpin with dubious steering rotation stiffness.

IO,
Giving consideration that you are making a valid point that I'm just not understanding in the context of your argument, let me provide some illustrations to better clarify what I am thinking when I read your points.  The number #10 image below shows your description of "rotation about the axis between the upper and lower Heims at the narrow end of the A-arms".  The 3 green directional arrows show the axis I believe you are describing since you said side to side movement is not in question.  The two yellow components are the spindles centered on the top and bottom king pins affixed to what I describe as the ?steering knuckle?. If that term is foreign to you what would you like to call it?  The vertical and horizontal black lines represent the center lines of the spindles through the king pins and center axis. 

When you say "the front wheel assembly is effectively mounted on a kingpin with dubious steering rotational stiffness" are you not describing virtually all common steering/spindle/kingpin configurations whether mounted to a-arms or bosses welded to solid axles?  Even struts act as the spindle where the top and bottom connections swivel about a centerline which serves the kingpin role.  Would the single connection point of the kingpin at an a-frame also be considered dubious based on your description here?  Why would two heim connection points be any more dubious than the one common ball joint connection at an a-frame?

Where is the "dubious steering rotational stiffness" you are describing?  Is it the king pin mounting bosses coming off the steering knuckle?  Are you saying those points have movement because the knuckle itself is held in place by the a-arms at their two heim connecting point?  Exactly where is the center and plane of the dubious rotational axis?  If its the plane represented by the 3 green arrows?  Where does the dubious rotation come into play?

So, lets say we have no front suspension and the steering knuckle is solid mounted to the frame as represented in attachment #11.  Here the knuckle is mounted at the same 4 flanges, two top and two bottom.  Do you still see dubious rotational stiffness when the spindles are steered left and right through the tie rod?

Attachment #12 shows the 6 degree extent of spindle movement to the right and inversely the same to the left.  Because this is a zero scrub radius steering setup I don't see the steering load on the steering knuckle which is a 110mm x 40mm cross section x 420mm diameter solid chunk of metal as a dubious component.  Neither do I see the connection points of the a-frames as questionable.  I might believe the a-frames themselves could be beefier but considering the low impact application of running up and down the salt I don't think so. But as always I could be wrong.   The yellow spindles will likely need to be beefier in real use but I'm not trying to engineer structural integrity in these drawings.  This is currently just a concept exercise.  Please help me to understand if you can what I am missing about your argument.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on August 01, 2019, 06:07:02 PM
Draw a line in 3-space from the upper Heim pair to the lower single Heim.  That is the axis, somewhat inclined from vertical, about which the whole thing is likely to rotate to some degree--the orange piece, yellow pieces, motors, wheels, tires etc.  If you were to grab the tires from the side and tried to steer them, they would wobble about that axis.  Resulting from dubious steering rotational stiffness.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on August 01, 2019, 06:38:41 PM
B/BGS      Eddie's Chop Shop, E. Umland, 8/18   369.162

   2004   Salt Shark
      2018 Custom EX7 Streamliner, 427" Chevy V-8
      Owner:  Ron Flattery ? Fremont, California
      Driver:  Tom Flattery
      Crew Chief:  Beth Zeigler 
      Crew:  Ed Flattery, Sharon Sam, Todd Hamor


Title: Re: Simspeed UWD LSR Design Project
Post by: sockjohn on August 01, 2019, 08:09:09 PM
There is a new streamliner that will probably be able to provide some input on this question. I am expecting this car to be very fast at Speed Week.

Rex

I assume that is front wheel drive?
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 01, 2019, 09:35:35 PM
Draw a line in 3-space from the upper Heim pair to the lower single Heim.  That is the axis, somewhat inclined from vertical, about which the whole thing is likely to rotate to some degree--the orange piece, yellow pieces, motors, wheels, tires etc.  If you were to grab the tires from the side and tried to steer them, they would wobble about that axis.  Resulting from dubious steering rotational stiffness.

IO...Is this the line the axis you claim the knuckle and all other attached components are "likely" to rotate to "some" degree? (see attached)
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 01, 2019, 10:10:49 PM
B/BGS      Eddie's Chop Shop, E. Umland, 8/18   369.162

   2004   Salt Shark
      2018 Custom EX7 Streamliner, 427" Chevy V-8
      Owner:  Ron Flattery ? Fremont, California
      Driver:  Tom Flattery
      Crew Chief:  Beth Zeigler 
      Crew:  Ed Flattery, Sharon Sam, Todd Hamor

Thanks for the info Stan.  Their FB page has all the build pics and good posts and comments from fans.  Interesting that he has a turbo 400 auto transmission in it.  I'm assuming they're not running the torque converter. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on August 02, 2019, 08:09:39 AM
Quote
IO...Is this the line the axis you claim the knuckle and all other attached components are "likely" to rotate to "some" degree? (see attached)
Yes, that is it.  I now note that in that illustration there are two lower Heims, which would improve the situation somewhat, but it is still open to question how stiff the arrangement would be.  Originally, working from LSR 5.3.9.JPG, it appeared there was only one lower pivot point.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 02, 2019, 04:27:04 PM
Yes, that is it.  I now note that in that illustration there are two lower Heims, which would improve the situation somewhat, but it is still open to question how stiff the arrangement would be.  Originally, working from LSR 5.3.9.JPG, it appeared there was only one lower pivot point.

Well I'm glad we were able to boil this down to simply a misinterpretation of what the illustrations were showing IO.  I believe stiffness is a function of geometry and structural integrity of components.  In this example both items were addressed sufficiently for the intended case based on my past experience with similar fabrications of tubular drag suspensions.  If we are able to move to a development stage all of these systems will be formally engineered.  I'm hoping that will come to pass.  Thanks for helping to sort this out... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 03, 2019, 05:14:35 PM
By refining the body geometry and re-configuring the chassis somewhat I was able to lower the frontal area another 10% to 4.774 sq.ft.  Without the active aero wing FA drops just under 4 sq.ft. again.  This body is much cleaner and better reflects what I'm hoping to achieve for this project.  I'm unsure which will be the better combination...more downforce at the expense of FA; or no active downforce and a 10% drop in NA.  I know weight is needed for traction but I'm not happy with adding a lot of ballast to get it.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 03, 2019, 05:26:50 PM
I borrowed from Eddie of Eddie's Chop Shop for the exhaust collectors.  His successful design and application of the heat spreading exhaust port is very impressive and works well for this relatively straight sided design.  By turning the IC/Gens upright like an outboard motor I was able to make better use of the available space to tighten up the width of the car while keeping the same track width as V.5.3.

On the subject of aero downforce would it be better to install a flat plate to the top of the body instead of the wing as shown?  The plate would tilt up like some jet air air brakes via the same hydraulic ram to expose more area to the airstream for downforce to gain traction for greater speed.  As with the current wing design the angle of the plate would be auto adjusted with the traction control to provide downforce as needed for traction.  Your thoughts... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on August 03, 2019, 06:27:36 PM
I've been studying the published FIA regulations as they relate to some of the questions that have come up in the discussion of this evolving concept. A few things I've noticed:

Per section D2.4.2, it looks like it's not a hybrid by their definition.

I can't find anything disallowing movable aero for category A (automobiles) although there is a specific entry allowing same for "Special" automobiles, apparently meaning rockets and jets, so maybe that  implies their prohibition for just plain automobiles. This may be irrelevant, however, because of section D4.2.7, which establishes an Absolute World Wheel Driven Record. 

Does anybody know anything for sure about this?
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 03, 2019, 11:26:45 PM
I've been studying the published FIA regulations as they relate to some of the questions that have come up in the discussion of this evolving concept. A few things I've noticed:

Per section D2.4.2, it looks like it's not a hybrid by their definition.

I can't find anything disallowing movable aero for category A (automobiles) although there is a specific entry allowing same for "Special" automobiles, apparently meaning rockets and jets, so maybe that  implies their prohibition for just plain automobiles. This may be irrelevant, however, because of section D4.2.7, which establishes an Absolute World Wheel Driven Record. 

Does anybody know anything for sure about this?

Hi Tortoise,
Thanks for looking these up.  It appears supercharged rotary engines vehicles are category A grouped under V and XV sections excluding electricity and solar power sources, and electrical engines under groups (XVIII, XV, VIII, VII).  So in our example what is the power plant and what is the source of power relative to these classifications?

Is the IC engine the engine type or generator for the source of power?  The wheels are driven by electric motors so should this be considered an electrical engine with an XVII and/or XIV external power source?  By FIA definition its not a hybrid as you say tortoise because it has no self-rechargeable energy... no batteries.  Because the supercharged rotary engines generate electricity which powers the electric wheel motors it appears this vehicle would most likely be considered and electric powered vehicle under the category A; XIV group.

The classification makes no difference to me as the goal is to claim the unlimited wheel driven record for a 4 wheel vehicle.  It might be more reasonable to classify this as a category C vehicle where the IC/Gen/Motor engine is a combination apart from those shown under category A.  Your thoughts?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 03, 2019, 11:36:07 PM
I'd like to get a comparison of frontal area between this project's latest design and other contending streamliners regardless of class.  Does anyone have FA info for 4 or more wheel streamliners? Let's include the bikes too. How about Cd numbers for any of the same?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: jacksoni on August 04, 2019, 06:29:49 AM
By refining the body geometry and re-configuring the chassis somewhat I was able to lower the frontal area another 10% to 4.774 sq.ft.  Without the active aero wing FA drops just under 4 sq.ft. again.  This body is much cleaner and better reflects what I'm hoping to achieve for this project.  I'm unsure which will be the better combination...more downforce at the expense of FA; or no active downforce and a 10% drop in NA.  I know weight is needed for traction but I'm not happy with adding a lot of ballast to get it.
You have to keep in mind that, more or less, HP required to overcome rolling resistance and mechanical drag goes up with the square of speed while HP to overcome aero drag goes up with cube of speed. Thus, in general, ballast is better than aero downforce.
Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 04, 2019, 08:42:20 AM
Thus, in general, ballast is better than aero downforce.

Unless you can get that downforce with little to no drag penalty (low ride height, flat bottom).

John
Title: Re: Simspeed UWD LSR Design Project
Post by: jacksoni on August 04, 2019, 09:43:01 AM
I am going to opine that best aero drag is with no lift or downforce, regardless of how it is obtained. Any change in that is a drag penalty. IO or others may chime in and say I'm wrong and I will be educated thereby.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on August 04, 2019, 11:07:02 AM
. . . in general, ballast is better than aero downforce.

Given a long enough course, more or less true. Even then, a heavily ballasted car can have a heat soak problem.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on August 04, 2019, 12:17:27 PM
The classification makes no difference to me as the goal is to claim the unlimited wheel driven record for a 4 wheel vehicle.
But can you run active aero? The Carbiliner has it, but they've never claimed an FIA record.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 04, 2019, 07:16:09 PM
The classification makes no difference to me as the goal is to claim the unlimited wheel driven record for a 4 wheel vehicle.
But can you run active aero? The Carbiliner has it, but they've never claimed an FIA record.
Well Tortoise I guess I'll have to ask the FIA about that unless someone already knows post the answer here.

Attach is my idea for a flat plate areo downforce device.  The NASA Foilsim app shows this will add 550 lbs of downforce and 137 lbs of drag at 250 mph which is the max speed for the app.  Much less than the wing but a smaller surface area.  Probably not very effective at slow speed.  It adds 1.47 sq.ft. to frontal area at max up angle but that reduces back to zero if lowered flat at speed.  Actual FA would depend on what angle is used through the end of the run based on traction needs. Also acts as an air brake if fully raised on shut down.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 04, 2019, 07:30:28 PM
You have to keep in mind that, more or less, HP required to overcome rolling resistance and mechanical drag goes up with the square of speed while HP to overcome aero drag goes up with cube of speed. Thus, in general, ballast is better than aero downforce.

Hi Jacksoni...yes, I see your point but there's a trade off in increased time to accelerate the added mass.  Ballast has shown to increase total speed so where the optimum for traction, speed and weight lies is anyone's guess.  Aero downforce gives you nothing at the start so traction will be limited to actual weight factored by applied torque and the traction coefficient of the salt.  One advantage this powertrain has is fine control of wheel motor torque that's not tied to the IC engines.  The electric motor controllers can be programmed for traction control that applies torque as needed tuned to track conditions. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: STICK777 on August 05, 2019, 01:23:02 AM
>Do you know what the drive train consist of?  Are there any links to the builder?  What's the name so I can look to see what I can find out about it?  Thanks... Terry

I think this hasn't been answered yet. The green car goes under the appropriate name of 'Salt Shark' , has indeed front wheel drive and is powered by a blown BB Chevrolet IIRC
running in B/GS.
You can find images and probably a bit more on here: https://www.facebook.com/pg/Bonneville-Salt-Shark-226594851348688/photos/?ref=page_internal
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 02:59:37 AM
>Do you know what the drive train consist of?  Are there any links to the builder?  What's the name so I can look to see what I can find out about it?  Thanks... Terry

I think this hasn't been answered yet. The green car goes under the appropriate name of 'Salt Shark' , has indeed front wheel drive and is powered by a blown BB Chevrolet IIRC
running in B/GS.
You can find images and probably a bit more on here: https://www.facebook.com/pg/Bonneville-Salt-Shark-226594851348688/photos/?ref=page_internal
Hi Stick,
Thanks for posting this.  We did get this link earlier and I spent a good deal of time going over all the build photos.  I really like what the owner has done in executing this novel design.  I hope he has a great event.  Anxious to see what the machine will do.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: jacksoni on August 05, 2019, 07:02:51 AM
You have to keep in mind that, more or less, HP required to overcome rolling resistance and mechanical drag goes up with the square of speed while HP to overcome aero drag goes up with cube of speed. Thus, in general, ballast is better than aero downforce.

Hi Jacksoni...yes, I see your point but there's a trade off in increased time to accelerate the added mass.  Ballast has shown to increase total speed so where the optimum for traction, speed and weight lies is anyone's guess.  Aero downforce gives you nothing at the start so traction will be limited to actual weight factored by applied torque and the traction coefficient of the salt.  One advantage this powertrain has is fine control of wheel motor torque that's not tied to the IC engines.  The electric motor controllers can be programmed for traction control that applies torque as needed tuned to track conditions. Thanks... Terry
I think this topic has come up before in your project. I mention it only because your initial premise for the car was the minimal frontal area and lowest possible Cd. Great goals. Most of the fast cars, not just the 'liners, have power in excess of traction and, within the rules struggle to improve aero in any meaningful way. Therefore ballast. Indeed accelerating the added mass is a problem and as you point out, the balance of power vs traction and at higher speeds the aero becomes the major factor. For cars like yours, there are no paved surfaces available, only salt or dirt and traction on those surfaces is variable foot by foot down the track so any attempt at calculating traction coefficients  really tough. Your traction control will go a long way to make things work but I think there is no way to really see what you need until you have an actual car and see what happens. Sure build it strong and it is going to "weigh  a ton" from the start. Maybe you don't need anything added but you have  the possibility of adding active aero  or ballast as needed and see what gives the best result.
Title: Re: Simspeed UWD LSR Design Project
Post by: Lemming Motors on August 05, 2019, 09:32:03 AM
I fall in the 'no lift or downforce' aero camp (active aero is another story and too sophisticated for my skills) but I am only mid build so can't prove anything.

The airbrake discussion made me think of the SLR's when the disc brakes of Dunlop were giving the Jags a shorter stopping distance on the Mulsanne ....
Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 05, 2019, 12:50:39 PM
I tried something like that once with my first road car but it was my hood that accidentally popped up. It did slow me down but caused a serious vision problem.

BTW, Sim, your car appears to be flat bottom with low ground clearance. That should provide a measurable amount of suction (downforce) with little if any drag.

John
Title: Re: Simspeed UWD LSR Design Project
Post by: Eddieschopshop on August 05, 2019, 08:54:16 PM
I like the exhaust.  I have never been able to really "prove" the results,  it would take a wind tunnel at full speed and the ability to put full load on the motor to really get accurate results.  On paper it makes sense.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 09:56:14 PM
I've worked up a skid stabilizer of sorts to help keep the car upright at slow speed.  The design is based on a double acting hydraulic cylinder where the ski shoes can pivot side to side at extension but sucks up to fit flush against a steel pocket welded to the chassis when retracted.  The height of the shoe bottom can be set wherever the builder chooses but is a fixed height once housing is welded in place.  The welded housing is 4" dia with likely 3.5" dia. extension tube.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 09:56:48 PM
Chassis view...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 10:04:27 PM
I think this topic has come up before in your project. I mention it only because your initial premise for the car was the minimal frontal area and lowest possible Cd. Great goals. Most of the fast cars, not just the 'liners, have power in excess of traction and, within the rules struggle to improve aero in any meaningful way. Therefore ballast. Indeed accelerating the added mass is a problem and as you point out, the balance of power vs traction and at higher speeds the aero becomes the major factor. For cars like yours, there are no paved surfaces available, only salt or dirt and traction on those surfaces is variable foot by foot down the track so any attempt at calculating traction coefficients  really tough. Your traction control will go a long way to make things work but I think there is no way to really see what you need until you have an actual car and see what happens. Sure build it strong and it is going to "weigh  a ton" from the start. Maybe you don't need anything added but you have  the possibility of adding active aero  or ballast as needed and see what gives the best result.
I think you are absolutely correct Jacksoni...see what we've got once the build is complete and test to find where the sweet spot is for all factors.  Programming for power output and traction control with an active aero element won't be one and done.  A lot will go into optimizing this combination.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 10:06:52 PM
I fall in the 'no lift or downforce' aero camp (active aero is another story and too sophisticated for my skills) but I am only mid build so can't prove anything.

The airbrake discussion made me think of the SLR's when the disc brakes of Dunlop were giving the Jags a shorter stopping distance on the Mulsanne ....

Thanks Lemming...I'd never seen that photo.  Makes great sense to use it as they did right?  I'm wondering how structurally sound that cover was and did it last long under load.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 10:09:39 PM
I tried something like that once with my first road car but it was my hood that accidentally popped up. It did slow me down but caused a serious vision problem.

BTW, Sim, your car appears to be flat bottom with low ground clearance. That should provide a measurable amount of suction (downforce) with little if any drag.

John

Hi John,
I drew up a tunnel floor with bottom exhaust for my initial design but abandoned that due to the need for added room on the floor to run the power cables.  Like you say the flat bottom will likely offer a good balance  of room and downforce.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 05, 2019, 10:23:10 PM
I like the exhaust.  I have never been able to really "prove" the results,  it would take a wind tunnel at full speed and the ability to put full load on the motor to really get accurate results.  On paper it makes sense.

Hi Eddie,
Glad you like my use of your design.  I think its a great idea pushing hot air down the side of the body to lessen skin layer friction.  From what I've been able to see in you photos you executed it nicely.  I wish I could apply it to both sides of this car but one side would have the exhaust dumping ahead of the intake and that wouldn't work.  Turning the two powerplants on end allowed use of your design and freed up room to place the motor controllers beside the IC/Gens by offsetting the engines a few centimeters toward the exhaust side of the chassis. 

I'm really happy with this current design as it gets the FA back to less than 4 sq.ft. as I first intended without crushing the driver into the cage which the first design did.  The more we work on this project the better the results with the input I've been getting from everyone.  We may not be there yet but I think it's getting really close.  I'm really interested in learning that FA and Cd other liners have for for comparison.  Any help from you guy would be appreciated.  Thanks... Terry

BTW...Good luck to everyone whose running Speed Week this year!!
Title: Re: Simspeed UWD LSR Design Project
Post by: Eddieschopshop on August 06, 2019, 10:20:53 AM
My frontal area is  6-7' even things as little as this can be debated where and how it gets measured.  I have to guess what my cd is as I have never had any cfd or wind tunnel testing done.  I am probably the lowest budget car to ever hit 400.  My personal opinion is that people sweat the drag stuff a little too much.  Of course do the best job you can, but I can tell you from personal experience,  that when you talk about being the fastest wheel driven car, accelerating the weight is a much bigger penalty.  The people who say that ballast isn't as big of penalty as drag are wrong.  It maybe  true for a car that hits terminal velocity before going through the lights though.   

One thing I do is compile a lot of real world data on acceleration.  A 500 lb weight loss would make a bigger difference than a 30 percent drag reduction.  Think about that.  I dont think I could lose 30 percent in drag no matter how much money I spent.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on August 06, 2019, 12:56:17 PM
A 500 lb weight loss would make a bigger difference than a 30 percent drag reduction.   
What are your speeds in gears and how soon can you use full throttle?
Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on August 06, 2019, 02:04:02 PM
We played the wing & ballast game on the road to 400+ & ended up without the wing & changed the ballast to find the sweet-ish spot. We were 2WD.
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: Eddieschopshop on August 06, 2019, 02:08:07 PM
My gearing is not ideal as my trans is put together from swap meet lencos.  That being said when I buy a new set of gears to get where I really want to be it will change those numbers.  I hold some of that info close.  I have only made three full passes in this car  352 385 403.  I have been creeping up on the power levels.  I will tell you that based on my possible hp I can give the car full throttle in fourth gear,  This should put nearly 50 mph on my best quarter mile speed to date.  I have been being conservative and whatever my top boost was for the run, I have been running 5 psi less in fourth.  This being said if things go well this years goal is to make a full power pass so I can say for sure what this engine package is capable of and then go on to a bigger engine. 

When developing this car a lot of decisions were made based on the engine I currently have and what I would run next.  The weight penalty of the 4 whd barely pays for itself at the power level I have run to date.  However my personal belief is that as I ramp in the power it will be the right choice.  On my car I have decided that any type of active aero doesn't gain me any appreciable speed.  As any additional downforce would only be desirable under 200 mph, above that it is extra drag with no benefit to my accel numbers
Title: Re: Simspeed UWD LSR Design Project
Post by: Eddieschopshop on August 06, 2019, 02:12:00 PM
We played the wing & ballast game on the road to 400+ & ended up without the wing & changed the ballast to find the sweet-ish spot. We were 2WD.
  Sid.

Do you feel the weight helped in traction or just got the center of gravity in a different spot which made the car drive different allowing more throttle?  I know it is a weird distinction but an important one that I don't think most people really try to understand. 
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 06, 2019, 05:57:46 PM
My frontal area is  6-7' even things as little as this can be debated where and how it gets measured.  I have to guess what my cd is as I have never had any cfd or wind tunnel testing done.  I am probably the lowest budget car to ever hit 400.  My personal opinion is that people sweat the drag stuff a little too much.  Of course do the best job you can, but I can tell you from personal experience,  that when you talk about being the fastest wheel driven car, accelerating the weight is a much bigger penalty.  The people who say that ballast isn't as big of penalty as drag are wrong.  It maybe  true for a car that hits terminal velocity before going through the lights though.   

One thing I do is compile a lot of real world data on acceleration.  A 500 lb weight loss would make a bigger difference than a 30 percent drag reduction.  Think about that.  I dont think I could lose 30 percent in drag no matter how much money I spent.

Thanks for sharing that Eddie.  I'm measuring FA as a cross section of the exposed body and appendages from nose to tail.  I haven't included the wheels as I expect the nose skirt will largely cover those.  Its pretty easy to do with the drawings as I can make multiple section cuts and then blend those to show the overall outline of exposed FA.  The program calculates the area within the outline in whatever increments I choose.

Comparing your average 6.5' to this car at a rounded 4' shows a 38.5% reduction in FA and an identical number in body drag force shown by the HP-Lakester weight needed spreadsheet I found here on the forum.  That's using the same 0.09 Cd number and 4000 total weight just for comparison purposed.  I'm using 0.09 Cd for analysis because that's the published number for the Buckeye Bullet III car arrived at through wind tunnel and CFD analysis.  Your body geometry and theirs appears to be very similar with yours probably slightly better because its somewhat shorter.  I think the Simspeed car is probably better still because it just looks slicker...if looks alone is any way of judging such a thing.  I certainly don't think it's worse.

The horsepower calculated for a given speed in this spreadsheet is bogus in my opinion as it shows you'd only need 410 hp to go 400 mph, and 1071 hp for 600 mph.  Where mine are 316 hp (23% less) and 755 (29.5% less) respectively.  I doubt anyone would agree with those numbers.

The hp calculator I found at https://www.rbracing-rsr.com/aerohpcalc.html (https://www.rbracing-rsr.com/aerohpcalc.html) shows 688 hp @ 400 mph for you and 577 hp (16% less) for me; with 2,494 hp @ 600 mph for you and 2117 hp (15% less) for me.  Given that aero drag is said to increase as the cube of speed, the 38.5% difference in FA between your car and my design would indicate a much greater difference in hp needed for these speeds all else being equal. 

JL222 commented he calculated the Summer bros needed 2400 hp to go 425 mph based on available input data using a program that he owned.  Unfortunately, he hasn't responded back what was needed for the Simspeed design based on the input data I posted for him. For $79 I guess I should just buy that program to see for myself.  Thanks for contributing Eddie...great help!
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 06, 2019, 06:03:07 PM
On my car I have decided that any type of active aero doesn't gain me any appreciable speed.  As any additional downforce would only be desirable under 200 mph, above that it is extra drag with no benefit to my accel numbers
That's the reason I decided to go with the flush plate active aero (AA) rather than the wing because the flush plate has no drag penalty once retracted.  The wing FA sticks out there even at zero angle of attack.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on August 06, 2019, 07:06:47 PM
We played the wing & ballast game on the road to 400+ & ended up without the wing & changed the ballast to find the sweet-ish spot. We were 2WD.
  Sid.

Do you feel the weight helped in traction or just got the center of gravity in a different spot which made the car drive different allowing more throttle?  I know it is a weird distinction but an important one that I don't think most people really try to understand.
You are correct Eddie, it is an important point. We added equal amounts of weight to both ends to not change the characteristics of the car. The only thing the wing seemed to change was the top end speed. Adding weight picked up the bottom end speed where you spend more time & that related to a better top end. The wing just took top end away.
  Sid. 
Title: Re: Simspeed UWD LSR Design Project
Post by: jl222 on August 06, 2019, 10:52:18 PM
 Simspeed .. My bville pro is not responding to streamliner data? Says inputs out of parameters?

 I have a Bville book with all the info on Summers Bros. Goldenrod but have been to busy with the 222 Camaro to look for it, From what I remember weight and hp were about the same as yours and I don't
remember the CD or frontal area but I know it was pretty good.

 i need to buy another program too as it's not transferable to my newer laptop.

    JL222
Title: Re: Simspeed UWD LSR Design Project
Post by: Eddieschopshop on August 06, 2019, 11:45:17 PM
That 2400 for the summer brothers really reinforces my point.  The drag to hp calculator is a very small part of the total equation in making a car that works.  Look at target 550 or should I say project 350?  There is more to racing than the numbers will have you believe
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 07, 2019, 12:21:27 AM
Simspeed .. My bville pro is not responding to streamliner data? Says inputs out of parameters?

 I have a Bville book with all the info on Summers Bros. Goldenrod but have been to busy with the 222 Camaro to look for it, From what I remember weight and hp were about the same as yours and I don't
remember the CD or frontal area but I know it was pretty good.

 i need to buy another program too as it's not transferable to my newer laptop.

    JL222
Uh Oh...wished I'd known that before ordering a copy for myself.  Paid for it but not yet delivered.  No refunds he says.  Oh well...we'll see what happens.  Good luck with the 222 JL.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 07, 2019, 12:26:47 AM
That 2400 for the summer brothers really reinforces my point.  The drag to hp calculator is a very small part of the total equation in making a car that works.  Look at target 550 or should I say project 350?  There is more to racing than the numbers will have you believe

No doubt Eddie.  I'm just looking for a baseline as compared to real world times/numbers from competitors like you and others.  More than likely this project will never see the salt but we have to start somewhere and see what develops.  I'd  like to know if the combination as shown could be competitive if everything came together as envisioned.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: desotoman on August 07, 2019, 12:30:09 PM
Look at target 550 or should I say project 350?  There is more to racing than the numbers will have you believe

Eddie,

Target 550 has gone 385 plus at Bonneville (that is what the timing slip says) with soft tuneup, on terrible wet salt, in and out of the throttle, in testing.

I don't think the "project 350" comment was necessary.

Tom G.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 08, 2019, 11:40:37 AM
I finally received the email to download the Bonneville Pro software and as JL222 stated it would not give results based on inputs for the Simspeed vehicle design.  Not only would it not allow the user to input actual horsepower and torque figures (it used some predetermined formula to calculate torque or hp depending in what was input first..?? Dumb), it also used a fixed range of some unknown index value for drive line slippage tied to engine rpm that made no sense to the user.  An "out of range" warning message was shown that stated the value was both too low and two high simultaneously but would not allow adjustments outside of the range...??  Gear ratios and rpm for each gear didn't apply because the project design calls for direct drive through the electric motors with an effective 1:1 final drive.  The program apparently doesn't allow direct drive scenarios.  Overall it was a complete waste of money with virtually no support or refunds.  Oh well...live and learn... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 08, 2019, 12:05:53 PM
At least for me, GearSplit was a much more accurate and reliable software to determine gearing, time/distance/speed and tire size for LSR cars. No limits either. Only downside is it has not been updated to run on a modern OS. Win XP is it so if you have an old computer, you are in luck. Also, the developer, Dave Dahlgren, has not sold a copy in a while. Worth contacting him, however.

John
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 08, 2019, 05:39:09 PM
At least for me, GearSplit was a much more accurate and reliable software to determine gearing, time/distance/speed and tire size for LSR cars. No limits either. Only downside is it has not been updated to run on a modern OS. Win XP is it so if you have an old computer, you are in luck. Also, the developer, Dave Dahlgren, has not sold a copy in a while. Worth contacting him, however.

John
Thanks John...I think I'll just research the formulas and build my own spreadsheet and see what I come up with.  Thanks again... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 08, 2019, 10:53:01 PM
After a few hours of research I found all the formulas required to accurately calculate drag, rolling resistance, and horsepower for a given speed.  Bonneville air density was gathered from today's weather reports and I used constants for converting metric values to U.S. standards.  So the results satisfy what we were hoping to learn.

Unfortunately, the needed horsepower exceeds what we planned for based on other hp spreadsheets we used at the beginning of this project.  Attached are three calculations for 400, 500, and 600 mph target goals.  460 mph is about the best we could hope to obtain with the current gen/motors.  The rotary IC engine output is good for 500 mph, but we'd either need more gen/motors or more powerful gen/motor specs to utilize that power.  We're going to need more than 3000 total hp from our IC/Gen/Motor package to have a chance at 600 mph with the current body geometry. 

We'll see what a third IC/Gen power plant and two more drive wheels look like in the next V.5.5 design.  Thanks... Terry

Title: Re: Simspeed UWD LSR Design Project
Post by: STICK777 on August 09, 2019, 01:58:46 AM
As it stands at the moment even 2500HP would be enough to put you in the history books as the first reaching, err  510+mph.  :wink:
So go for it!   :cheers:

PS. We'll see what Speedweek will bring...
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on August 09, 2019, 10:31:10 AM
As it stands at the moment even 2500HP would be enough to put you in the history books as the first reaching 500+mph.  :wink:
So go for it!   :cheers:

PS. We'll see what Speedweek will bring...

The wheel driven 500 mph mark has already been breeched, Turbonator II (503.332 mph) terminal speed.    :cheers:

Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 09, 2019, 11:02:34 AM
The wheel driven 500 mph mark has already been breeched, Turbonator II (503.332 mph) terminal speed.

But a record at or over 500 mph has not.

John
Title: Re: Simspeed UWD LSR Design Project
Post by: STICK777 on August 09, 2019, 12:19:32 PM
As ggl says... breaching is not enough. Terminal speed is not a record.
Turbinator probably has more than 2500HP in its turbine, so we'll see whether they can go for the record.
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on August 09, 2019, 03:13:29 PM
I am quite aware that the Turbinator II has not set a record of 500+ yet.

I was responding to Stick saying "the first reaching 500+ mph", which they did.

Sorry for any confusion, carry on.

  Don

Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on August 09, 2019, 08:37:27 PM
After a few hours of research I found all the formulas required to accurately calculate drag, rolling resistance, and horsepower for a given speed.
Your charts show the same rolling resistance at all speeds, a force much higher than the air resistance. I had understood that rolling resistance went up more or less linearly with speed, and that at high speeds it was relatively much smaller than aero drag. What's going on here?
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 10, 2019, 07:42:46 AM
After a few hours of research I found all the formulas required to accurately calculate drag, rolling resistance, and horsepower for a given speed.
Your charts show the same rolling resistance at all speeds, a force much higher than the air resistance. I had understood that rolling resistance went up more or less linearly with speed, and that at high speeds it was relatively much smaller than aero drag. What's going on here?
Hi Tortoise,
There's a "LOT" of debate on the effects or no effect of speed on rolling resistance values.  The power formula I'm using here does factor Cr coefficient into account where speed is a calculated input to find power required to overcome aero drag and rolling resistance drag.  The line item values for Rolling resistance and Body Drag are fixed values using what I found to be the stand alone RR formula F = Cr x W; (Force= RR coefficient x Weight) where speed isn't factored.  The numbers don't change because in all three examples the Cr and W don't change.  So effectively the line items don't factor speed into the posted results but the power equation does.

I found numerous definitions of RR formulas that claim speed is irrelevant as velocity increases, but I chose the formulation where speed is factored.  The Cr value of 0.039 I'm using here is said to be representative of the Cf (coefficient of friction) for hard packed sand at high speed which is the closest example to salt that I could find.  I did find agreement with your statement that RR is more or less consistent with the linear increase in speed where aero resistance rises exponentially with the same increase in speed.  Yes...somewhat confusing I admit but its apparently a very complicated subject.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 10, 2019, 08:45:13 AM
In V.5.5 we've increased Gen/Motors to 12 each for a total of 2400 kW (3200 hp) and upped the power output of each of the 8 IC rotors from a conservative 300 hp each to a doable 400 hp with NO2 for a total of 3200 IC hp.  By stacking 3 generators to each 2 rotor power module we match total kW to IC hp capability (804.6 to 800).  We still needed to add 4 additional drive motors (2 wheels) to the drive train for a total of 6 wheels.  These fit nicely within the existing body and increased the overall length by a little over 2 ft.  All 6 wheels are spaced differently within the chassis so none track directly behind any other.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 10, 2019, 08:49:44 AM
We rearranged the powerplants moving the rear engine, fuel, and oil tanks forward and the NO2 bottles rearward for a better Cg.  The aero wing moved forward too and the hydraulic cylinder for the wing was positioned vertically to allow for better spacing and operability.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 10, 2019, 08:54:19 AM
We replaced the outrigger shoe for a half sphere that spins about the centerline of the extendable shaft.  This presents a more stable contact point for the outrigger in the event of a roll condition at slow speed.  Once the car is in stabilized motion the outriggers will be retracted by the driver.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 10, 2019, 09:02:32 AM
This addition is probably controversial but we think it's a good application to help keep the vehicle upright due to the very narrow track width (12.8") at the front tires.  We believe these changes in hp and added traction from 6 driving wheels put us back on track for record setting potential.  To the best of our knowledge this design has the lowest aero drag with sufficient power of any unlimited wheel driven vehicle.  Thanks... Terry   
Title: Re: Simspeed UWD LSR Design Project
Post by: GW on August 10, 2019, 09:55:44 AM
So many updates in so little time doesn't allow me to keep up.

1. I recall a while back the DIF debate; with the DIF as shown, how did that debate resolve itself with the recommendations to not do so?
2. FWIW, and with no facts or data, I recommend the outrigger shoe as to what appears would be a point load from a hemispherical contact point.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 13, 2019, 04:07:07 PM
Hi GW,
Thanks for your comments.  My thinking on the ball shoe is that it will will rotate like a small wheel presenting a uniform contact point that has no sharp edge to dig into the salt.  The skid shoe as drawn could roll under and cause a sharp point contact at the end of the shaft that would dig into the salt and pivot the car destructively.  I don't think the ball shoe would do that but I could be wrong.  I guess it depends largely on how high the shoe is off the salt surface when fully extended.  The closer to the surface the more the ball shoe would act like a wheel limiting vertical angular movement of the body.  As with everything I present with these drawings I'm looking for critiques from members like you to help me think through things to hopefully arrive at practical solutions.

The DIF debate isn't over at this point.  The recommendations to not use a DIF layout are warranted as I agree there will be less mechanical feedback to the driver over a DIM or DIR position.  However, there was confirmation from Sparky that in his experience a yaw string works in providing useful feedback of the car's movement relative to cues the horizon presents at speed. So far no one has commented to the contrary. 

Looking back at Cobb and Campbell's cars of the 30's and 40's they had no reported issues arising from their DIF chassis layouts.  Nothing I could find said they used yaw strings to help with yaw feedback, but they apparently were able to overcome the lack of a seat of the pants feel that rearward driver positions are said to offer.  Here, the smallest frontal area possible is needed to take full advantage of the powertrain design for record speeds.  Based on the many different layouts we've covered so far the DIF position in V.5.5 is the best approach to maximize the hp to drag ratio numbers needed to hit a 600 mph goal.  So, unless we receive factual information to the contrary of the usefulness of a yaw string indicator we will progress forward with the current DIF layout.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Sumner on August 13, 2019, 04:57:12 PM
I'll have to agree with those that feel you can't be looking down the track and at something right in front of your face at the same time.  You mentioned Cobb or Campbell (can't remember which) crashing due to salt conditions.  How do we know they couldn't correct for those conditions due to their seating position?  On almost any run by a fast high powered car they are dealing with salt conditions as the track isn't anywhere near as consistent as say pavement.  It can look fast and hard and smooth but it isn't.  Your car has the potential to go much faster than Cobb and Campbell went so the driver is going to need all the help he or she can get.

My feeling on using something that is controversial from a safety standpoint is if it is my car and I'm driving it I might try something that I wouldn't try with someone else's life on the line.

Sumner
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 14, 2019, 12:50:50 AM
I'll have to agree with those that feel you can't be looking down the track and at something right in front of your face at the same time.  You mentioned Cobb or Campbell (can't remember which) crashing due to salt conditions.  How do we know they couldn't correct for those conditions due to their seating position?  On almost any run by a fast high powered car they are dealing with salt conditions as the track isn't anywhere near as consistent as say pavement.  It can look fast and hard and smooth but it isn't.  Your car has the potential to go much faster than Cobb and Campbell went so the driver is going to need all the help he or she can get.

My feeling on using something that is controversial from a safety standpoint is if it is my car and I'm driving it I might try something that I wouldn't try with someone else's life on the line.

Sumner

Hey Sumner,
My contention is that the driver, like a pilot, doesn't have to look directly at the yaw string to benefit from the information it supplies.  I believe you can look down the track and still register movement of the string without looking at it directly.  Because it gives real time information of yaw movement a driver should be able to make use of that info in real time to make counter steer corrections.  I agree on the safety issue to the extent that I'd rather test something new myself rather than ask someone else to take the risk.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on August 14, 2019, 01:14:23 AM
I'm not trying to be a smart a$$ but I just had an idea. Why don't you try mounting a devise of that sort on your regular street vehicle and then see if you feel it is really practical. I think you may change your ideas.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: TrickyDicky on August 14, 2019, 02:17:43 AM
I'll have to agree with those that feel you can't be looking down the track and at something right in front of your face at the same time.  You mentioned Cobb or Campbell (can't remember which) crashing due to salt conditions.
...
Sumner
I think the reference was to Donald Campbell in 1960.

As far as I know, Malcolm Campbell never crashed (at Bonneville). His Blue Birds were also not DIF.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on August 14, 2019, 03:28:31 PM
Last I checked, an Isky Dream Wheel is $2.  They seem to be accurate to within 1% if you carefully use them.  The app allows you to carry it with you wherever you are and whether or not there is a signal available.  We got 7 SCTA records in the same category using one.  Just a thought.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 15, 2019, 09:12:05 PM
Congratulations to the Salt Shark team for their 288 mph for what I believe is the top speed of the meet.  The owner gave credit to his FWD setup for being able to deal with the poor track conditions.  Conditions must have been pretty bad for a 288 to take top speed.

But that leads to the question of how successful might a FWD setup be if that's all the traction put to use? Given equal HP might the FWD Salt Shark for example outperform the RWD Speed Demon?  How about the Simspeed project if FWD were tagged from start to say 300 mph, and then the RWD kicks in with 4 more wheels to boost max hp to the ground for whatever top speed can be reached?  With electric motor drives at all wheels power can be applied to each wheel independently at any given point in the run to best advantage depending on conditions.  Remember there's no transmission or gearing involved, the motors are direct drive with 3218 hp & 3270 ft/lb torque spinning up to 8600 rpm to reach 600 mph with the 23.5 wheel diameters.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Seldom Seen Slim on August 15, 2019, 09:52:42 PM
Well, mmm, unh, the 715 car made three runs over 300 during the event. :roll:
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on August 15, 2019, 10:58:48 PM
Congratulations to the Salt Shark team for their 288 mph for what I believe is the top speed of the meet.                                                     715 E BFS Speed Demon Racing 332.815
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 16, 2019, 12:29:35 AM
Well, mmm, unh, the 715 car made three runs over 300 during the event. :roll:
Oh...my apologies to the Speed Demon team.  What I read was prior to those runs apparently.  Thanks for the correction guys... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on August 16, 2019, 01:13:39 AM
Congratulations to the Salt Shark team for their 288 mph for what I believe is the top speed of the meet.                                                     715 E BFS Speed Demon Racing 332.815


SCTA website list Speed Demon at 369 MPH for fast time. (8/15)
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on August 16, 2019, 09:29:28 AM
Never the less, For a new, unconventional car. On that course. I think the Salt Shark did very well. Hats off to you guys.
Title: Re: Simspeed UWD LSR Design Project
Post by: Rex Schimmer on August 20, 2019, 05:16:33 PM
Terry,
I am sure that some place in your presentation is the reason that you are not planning to just use an all electric drive, i.e. battery packs and high performance electric motors as you are already proposing for your final drive. Either approach will require some very challenging electronic control engineering but with an all electric drive and the 12,000 ft altitude of the salt lake in South America it would seem the all electric approach would have a huge advantage.

I have to say again that I am very impressed with your engineering and CAD abilities. I think it shows how quickly a very viable design for a landspeed car can be generated and modified quickly to provide the latest design thoughts of the engineer. I at first did not follow you thread because I thought it was a "flash in the pan" but with your continued efforts and constant modifications that are so well shown in your CAD drawings it is one of the first things I look at.

Rex
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 20, 2019, 06:27:11 PM
Terry,
I am sure that some place in your presentation is the reason that you are not planning to just use an all electric drive, i.e. battery packs and high performance electric motors as you are already proposing for your final drive. Either approach will require some very challenging electronic control engineering but with an all electric drive and the 12,000 ft altitude of the salt lake in South America it would seem the all electric approach would have a huge advantage.

I have to say again that I am very impressed with your engineering and CAD abilities. I think it shows how quickly a very viable design for a landspeed car can be generated and modified quickly to provide the latest design thoughts of the engineer. I at first did not follow you thread because I thought it was a "flash in the pan" but with your continued efforts and constant modifications that are so well shown in your CAD drawings it is one of the first things I look at.

Rex
Thanks for your kind and encouraging words Rex, its great to receive such valuable input from yourself and others who have shown an interest in this design project.

My reasoning for the IC engine component for this design has to do with packaging and weight.  My goal from the beginning has been to produce an aerodynamic design that breaks the 4 sq.ft. FA barrier.  The latest version using modified 13B rotor powerplants, wheel motors, and a DIF layout accomplishes that. 

I looked at the successful Buck Eye Bullet effort in detail and found in my opinion that weight, FA, and motor/drive train choice were their biggest drawbacks.  They reported the car weighs over 8000 lbs primarily from 2 mW of battery mass.  The Simspeed IC/Gen powerplants and NoS should weigh 1200 to 1500 lbs total.  We're shooting for 4000 to 4500 max vehicle weight with a 47.6% smaller frontal area than the BB3 vehicle's 7.64 sq.ft.

I haven't looked at V.5.5 hp requirements for the Bolivia salt flats.  My guess is the reduced aero drag at that altitude will compensate for the loss of IC hp added NoS can't provide.  I do agree however that we will likely need to run at that location to reach top speed.  I'm disappointed like others that we didn't see the Ack Attack liner prove record speeds were attainable at that altitude.  Does anyone know of successful record attempts in Bolivia?
Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 20, 2019, 06:48:36 PM
Don?t forget Australia.

John
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 20, 2019, 06:58:00 PM
We continue to tinker with component locations in an attempt to optimize Cg and Cp.  Here in V.5.6 we've moved the IC/Gen powerplants forward together to offset the added weight of the third set of drive wheels required for calculated hp requirements. We've also come to the conclusion that a detachable carbon fiber driver tub is the better option in terms of crash safety and cantilevered weight savings at the nose of the car.

We're giving some thought to adding an active rudder to the stabilizer fin for yaw control.  That's the easiest way to adapt a yaw control mechanism at the rear of the vehicle.  I read where the Honda F1 team added a rudder to their car using a closed loop control program that adjusted rudder position relative to yaw angle.  Their car still spun so not sure attempting to program rudder movement rather than using driver foots controls would be the better option.  Any opinions?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 20, 2019, 07:00:03 PM
Don?t forget Australia.

John
Personally I'd rather run at Australia than Bolivia for logistical and language reasons.  Do you know what the usable length of track surface is there John?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: ggl205 on August 20, 2019, 07:07:42 PM
Not sure what is now available but when we ran there in 1995, we had ten miles of groomed surface. Well, let?s just say it was dragged but still pretty rough. Today, I hear dragging has greatly improved with a correspondingly smoother surface. A quick check with DLRA should provide more useable information. If I had the funds, I would go back.

John
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on August 21, 2019, 08:35:44 AM
I ran across this DIF car on FB...can't find any more about it.  Anyone know something about this one?  Thanks... Terry

Apparently there is/are steering wheel(s) ahead of the driver.  I'd still like to know more about this interesting vehicle if anyone knows.
Title: Re: Simspeed UWD LSR Design Project
Post by: TrickyDicky on August 21, 2019, 10:41:11 AM
Not sure what is now available but when we ran there in 1995, we had ten miles of groomed surface. Well, let?s just say it was dragged but still pretty rough. Today, I hear dragging has greatly improved with a correspondingly smoother surface. A quick check with DLRA should provide more useable information. If I had the funds, I would go back.

John

According to the DLRA web site, they are planning an FIA/FIM event at the end of March 2020.

Track will be 11 miles long with the middle mile timed (giving 5 miles before the clocks in each direction).

Title: Re: Simspeed UWD LSR Design Project
Post by: Malcolm UK on August 21, 2019, 11:20:48 AM
The question was asked at #168 about records in Bolivia on their salt flat at altitude. FIM bike records have been achieved and Ralph Hudson rode a GSXR-1000 bike to 298mph, in partial streamlined form.
Title: Re: Simspeed UWD LSR Design Project
Post by: STICK777 on August 21, 2019, 12:29:59 PM
>I ran across this DIF car on FB...can't find any more about it.

Beautiful car. You probably know all there is already, but it's now named 'Albion Arrow' and runs in J/FS.
To my knowledge did one run at Speed Week and reached 147mph... for now.

Didn't find anything else myself.


Edit: I didn't insert that emojie... :)
Title: Re: Simspeed UWD LSR Design Project
Post by: superleggera on September 06, 2019, 04:04:11 PM
@Terry.  Updates?  Did you make it out to SpeedWeek this year and converse with some of the streamliner guys to further your education?    Inevitably there is a massive amount of knowledge and talent out there on the salt to learn from.  Hopefully you had the chance to take advantage of it.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:50:56 PM
It's been a little while but I've come up with a radical revision that does away with the electric gen/motors and now relies totally on IC rotary power.  I came to the realization that because the custom gen/motor and rotary IC powerplants we designed were the same diameter and width we could simply replace the electric wheel motors with IC rotary engines and do away with all the electric power components and keep the same body geometry. 

So here we see elimination of the separate IC/Gen powerplants and moved the rotatory engines into the wheel envelops.  By spreading out the drive wheels into a "V" pattern with two inline sprung steering wheels with a single rotor engine each, followed by a two rotor engine with wider wheel track, and a three rotor engine package with the widest wheel track we effectively have a traction foot print the full width of the car with not much overlap.  The non-powered trailing wheel at the back carries the disc brakes and supports the back half weight of the car.

By moving all the traction wheels and greatest portion of weight to the front of the car we should see more stable handing resulting in better control for the DIF driver position.  The reported stability of the FWD Salt Shark was the impetus for moving the power wheels forward for this design.  We've dropped the rotor count from 8 to 7 in this design but there's room to increase over all power from 3200 hp to 3500 hp by shooting for 500 hp per rotor which has proven doable by a number of drag teams who are pushing 1300 hp from 13B 2 rotor turbo engines.  It's been shown in a number of different engine combinations that NOs can generate power output comparable to high boost turbos.  Hopefully that will translate to the salt successfully.

Weight reduction is a big factor with the all IC wheel motor design.  Eliminating the electrical drive components saves upwards of 1500 lbs which I think now makes total weight between 3000 and 3500 lbs possible.  The design uses no clutch or transmission as each of the six traction wheels are directly driven by the attached rotor engines.  Push starts are mandatory with ignition switched on to create combustion power to the wheels.

The power between wheel pairs is not mechanically linked.  We've combined the throttle bodies and intake plenum for the two rotor and three rotor engines so they breath common air and share that control signal.  The two steering wheels have separate throttle bodies and air boxes so controlling the spark through a single engine controller for all rotors is the sync method to be used in conjunction with calibrated throttle linkage.

We've shortened the car roughly 5 feet and increased the track width of the widest wheel pair to 16".  I tried first to move the three rotor engine to the front and steer with those wheels but that combination was just too cumbersome to be practical within the existing body geometry.  Going with inline steering wheels with single rotor engines worked out nicely.

All in all, I think this design offers a better chance for record speeds even with the lack of mechanical synchronization between the powered wheels.  Your thoughts... Terry.  Thanks...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:52:06 PM
Follow up drawings...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:53:02 PM
The drawings aren't in order due to the size limitations...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:54:28 PM
Big file sizes...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:55:44 PM
Jumping around so not to exceed the file size restriction...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 01:56:34 PM
Almost there...
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on September 08, 2019, 03:17:03 PM
"The power between wheel pairs is not mechanically linked.  We've combined the throttle bodies and intake plenum for the two rotor and three rotor engines so they breath common air and share that control signal.  The two steering wheels have separate throttle bodies and air boxes so controlling the spark through a single engine controller for all rotors is the sync method to be used in conjunction with calibrated throttle linkage."

I seem to remember that the JCB DieselMAX had a problem of getting their two engines to synchronize properly.

Regards, Neil  Tucson, AZ
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 08, 2019, 05:18:08 PM
@Terry.  Updates?  Did you make it out to SpeedWeek this year and converse with some of the streamliner guys to further your education?    Inevitably there is a massive amount of knowledge and talent out there on the salt to learn from.  Hopefully you had the chance to take advantage of it.

Just in time for the latest update Super.  :-)  No I didn't get to go to SpeedWeek this year but I'm hoping to do so next year.  For now I'll look to you guys (gals) here to help educate me on the fine art of land speed racing.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: DaveL on September 09, 2019, 07:50:04 AM
Hi Terry,
I've been following this build diary with interest and couldn't help notice the similarity with your latest revision and that of fellow Australian Johnny Conway's 'Mach 1' LSR car from the mid seventies. How are these for specs; 32 rotary engines arranged in pairs directly attached to 16 solid aluminium drive wheels, some pairs fixed and some steered. No clutch or transmissions so push start only. Four more rotary engines driving superchargers for the main drive engines. Even looked vaguely similar to your latest design however he lay prone at the rear and used cctv for forward vision. Predictably it was never finished, hope the same doesn't become of your project.
Cheers, Dave.
Title: Re: Simspeed UWD LSR Design Project
Post by: Interested Observer on September 09, 2019, 08:41:11 AM
Comments on latest version:
Is power curve compatible with wheel speed and power needed for both acceleration and top end?  Wankels notorious for gutless low end.  If it won?t accelerate from 50 mph, probably won?t get to 500.
Good luck push-starting 7 independent and rotationally uncoordinated IC engines.
With 5 axles, wheel load distribution is all over the place and variable.  Tail wheel detracts from power wheel traction.
Very wobbly chassis in lateral and torsional motion at two-rotor location.
Steering so close to main power wheels gives little leverage or fine control.  Steering will be fighting the tail wheel as well as trying to side-slip the power wheels.
Assuming there is a CV joint of some sort in the steering upright member.  Otherwise kinematically incompatible with suspension movement.  In any case, suspension movement induces lateral movement of the contact patch.  Probably unsettling for driver.
Rear aero yaw ?control? a bad idea.  Also induces roll.
Braking capability appears to be far in excess of what can be put to the ground through one alloy wheel.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 09, 2019, 11:40:34 AM
Hi Terry,
I've been following this build diary with interest and couldn't help notice the similarity with your latest revision and that of fellow Australian Johnny Conway's 'Mach 1' LSR car from the mid seventies. How are these for specs; 32 rotary engines arranged in pairs directly attached to 16 solid aluminium drive wheels, some pairs fixed and some steered. No clutch or transmissions so push start only. Four more rotary engines driving superchargers for the main drive engines. Even looked vaguely similar to your latest design however he lay prone at the rear and used cctv for forward vision. Predictably it was never finished, hope the same doesn't become of your project.
Cheers, Dave.

Hi Dave,
Thanks for the lead to Conway's 'Mach 1" LSR car.  I'd never heard of it before so cool to see how someone else approached using rotary power for an LSR car.  Both designs are unique even with the direct driven wheel commonality.  I would love to have seen his design hit the salt.  The likelihood of my design ever seeing the light of day is slim at best but one can hope and pray it will and leave the rest up to God's will.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 09, 2019, 06:38:14 PM
Comments on latest version:
Is power curve compatible with wheel speed and power needed for both acceleration and top end?  Wankels notorious for gutless low end.  If it won?t accelerate from 50 mph, probably won?t get to 500.
Good luck push-starting 7 independent and rotationally uncoordinated IC engines.
With 5 axles, wheel load distribution is all over the place and variable.  Tail wheel detracts from power wheel traction.
Very wobbly chassis in lateral and torsional motion at two-rotor location.
Steering so close to main power wheels gives little leverage or fine control.  Steering will be fighting the tail wheel as well as trying to side-slip the power wheels.
Assuming there is a CV joint of some sort in the steering upright member.  Otherwise kinematically incompatible with suspension movement.  In any case, suspension movement induces lateral movement of the contact patch.  Probably unsettling for driver.
Rear aero yaw ?control? a bad idea.  Also induces roll.
Braking capability appears to be far in excess of what can be put to the ground through one alloy wheel.

Hi IO,
Thanks for all the identified issues...exactly what I'm looking for from the forum.  I'll address my thinking on these items as follows:

For clarification, the 7 rotors are combined in the following groupings: (1) three rotor engine; (1) two rotor engine; and (2) one rotor engines for a total of 4 powerplants driving 6 wheels.  The 7th trailing wheel is not powered.

Power curve:  The 23.5 diameter aluminum wheels turn 8582 rpm @ 600 mph (7152 rpm @ 500 mph).  Consequently the direct drive engines turn the same rpm as the wheels for all speeds.  Since salt traction is at a premium, running a low torque powertrain with a lot of contact patch would seem idea if power increases significantly with rpm up to the distance limit. I would imagine the ideal power curve would allow max rpm to hit at the max distance.  The power curve question you posed IO depends on mass, drag, and traction between 0 mph and whatever rpm is achievable by the 5 mile marker. 

I'd say we'd need a push truck with gearing and torque to hit 150 max speed by the 1/2 mile mark. That's 2145 rpm on the engines where I believe the power curve would begin to kick in relative to vehicle mass.  Dropping total weight down between 3000 to 3500 lbs would go a long way toward a desirable acceleration rate.  BTW... what's the push distance limit?

Push starting:  I personally don't see a problem push starting the 4 engines.  With zero slippage, all 6 wheels in contact with the track surface will be turning the same rpm when the ignition is lit. The 3 and 2 rotor engines will each use a common crank/axle so those rotors will be rotational indexed to fire in the proper sequence.  The 2 single rotor engines will run independently but throttle matched to the 2 and 3 rotor engines.  Only when wheel slippage occurs will we see a disparity between engine rpm(s) but common ramp settings across the throttle bodies should compensate to bring that back in line within some acceptable range.  At this time I have no idea what that would be.

Wheel load distribution:  The two steering wheels are sprung so the 3 fixed axles will be most affected by load distribution.  On a perfectly flat surface loads would be balanced relative to Cg for all wheels I believe.  From appearances I think the Cg will be close to the axle centerline of the 3 rotor engine.  Depending on chassis flex effective load on the trailing wheel will be a non-issue traction wise to the forward power wheels.

Wobbly chassis:  I agree with your comment here.  I've included a drawing showing added reinforcements to that section of the chassis.

Steering:  I think there's an advantage here from the two inline steering wheels.  The angular distance between the lead steering wheels and the fixed wheels offers a slight benefit over a single steering wheel or a pair of side spaced wheels.  I've also been told its beneficial to slow the steering way down on these cars over what we might otherwise think it should be, so effectively we're getting that here with this arrangement.

I see your point about the steering wheels fighting the trailing wheel with the fix wheels in between. We could use a center swivel for the trailing wheel much like the tail wheel of a tail dragger airplane.  It would then be easy enough to add sprung suspension for that trailing wheel.

CV Joint:  Yes indeed there are CV joints drawn within the steering spindles.  The upper and lower arms that center the spindle hinge in alignment to one another such that there is no camber change throughout the suspension movement. Because the spindle center is aligned with the center of the wheel there is zero scrub angle as well.

Rear Aero Yaw control:   I remember posing this question a while back, thanks for responding.  I have no such controls draw into this design.

Braking Capability:  Yes, I recognized that too so I'd say this is a redundancy rather than a necessity.

Thanks IO... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Bratfink on September 19, 2019, 02:19:27 PM
Terry,

How are you deriving your Cd, Cp, Yaw rate etc and other aero numbers?
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on September 20, 2019, 03:45:47 AM
Quote
Terry: We could use a center swivel for the trailing wheel much like the tail wheel of a tail dragger airplane.  It would then be easy enough to add sprung suspension for that trailing wheel

Simple test to delete that idea is to look at supermarkets' trolley wheels whizzing about from side to side with no coordination whatsoever while irate pusher is attempting to push in a straight line!!!

Also, push start to 150mph... You'll then need another LSR car with a gear box (and probably more power than your LSR car) to start this LSR car???

Why not simplify this drastically and transfer the engine and gear box from this LSR pusher to that LSR car?

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: JR529 on September 20, 2019, 11:07:04 AM
I'd say we'd need a push truck with gearing and torque to hit 150 max speed by the 1/2 mile mark.

The benefit of pushing to 150 by the 1/2 is the removal of any need for brakes or parachutes on the car since the resulting crash will slide/tumble to a stop around the one.

This also has the added benefit of allowing the safety equipment to be pre-staged there since the final location of the accident debris is pretty much a given.
Title: Re: Simspeed UWD LSR Design Project
Post by: dw230 on September 20, 2019, 11:32:04 AM
Have you ever driven a pushee at 150 mph. A bit on the difficult scale.

DW
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 20, 2019, 01:13:14 PM
So all you need is a push truck that will go 150 while push starting your liner in 1/2 mile? On salt? Sounds like you need to start a new build diary. This is going to be a pretty fast pickup.
Title: Re: Simspeed UWD LSR Design Project
Post by: jl222 on September 20, 2019, 01:38:17 PM
 
 Carl Heaps push truck? :-D

             JL222
Title: Re: Simspeed UWD LSR Design Project
Post by: Seldom Seen Slim on September 20, 2019, 01:51:58 PM
" Carl Heaps push truck? :-D"

HahahaHaha!  Good one, Mr. Langlo, sir!
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 04:11:52 PM
Terry,
How are you deriving your Cd, Cp, Yaw rate etc and other aero numbers?
Hi Bratfink,
At this stage all I can do is compare the current body geometry to Cd, Cp, frontal area, weight, and hp of existing liners where the information is published. The Buckeye Bullet 3 and the JCB DieselMax liners both published that information based on CFD analysis, dyno results, and physical data.

The BB3 has a Cd of .09 and frontal area of 7.5 sq.ft. I think it was, and weight of 9000 lbs with 2 mW power (2682 hp).  The JCB liner has a Cd of .14 and 12.4 sq.ft. frontal area @ 5800 lbs with 1500 hp.  Those numbers may not be exact I'm recalling them from memory.  Both cars went 350 mph. 

What I find interesting is the reported hp numbers for both cars.  The JCB effort @ 1500 hp is way lower than 2413 hp my formulas say is needed for 350 mph.   The BB3 car on the other hand shows a need of 3484 hp using my formula primarily due to the added weight which factors into the Cr.

Assuming same .09 Cd for the SSpeed body geometry (from appearances I believe the SSpeed geometry is better than the BB3 number) the known 4 sq.ft. frontal area, and a revised weight of 3000 lbs (or less) due to new construction using CF tubing, CF plate, and 3D printed titanium tubing connectors (see drawing below) my formula shows a need of 1195 hp for 350 mph.  If we say my formulas overstate the needed hp (given that both the JCB and BB3 cars hit that speed with less hp than my formulas show) then 38% and 23% less hp respectively for the JCB and BB3 cars would equate to and average of 30% less or 836 hp needed for the SSpeed design @ 350 mph; or 1639 hp @ 600 mph.  My formulas now show a need of 2342 hp @600 mph based on the new 3000 lb weight.  At the old 4500 lb weight the hp needed was 3291.  This is all speculation of course but for now that's all I have to go on.

If you or anyone has known Cd, Cp, FA, weight and hp values for other record setting efforts please share them so I can plug them into the formulas in an attempt to make whatever corrections are needed.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 04:28:06 PM
Quote
Terry: We could use a center swivel for the trailing wheel much like the tail wheel of a tail dragger airplane.  It would then be easy enough to add sprung suspension for that trailing wheel

Simple test to delete that idea is to look at supermarkets' trolley wheels whizzing about from side to side with no coordination whatsoever while irate pusher is attempting to push in a straight line!!!

Also, push start to 150mph... You'll then need another LSR car with a gear box (and probably more power than your LSR car) to start this LSR car???

Why not simplify this drastically and transfer the engine and gear box from this LSR pusher to that LSR car?

Patrick

Hi Patrick,
Yes I agree, rear single point pushing anything with a free pivoting real wheel won't work.  But as they say there's more than one way to skin a cat.  The pivoting trailing wheel is just another idea that may or may not be feasible.  I'm looking to you guys to help keep my ideas from drifting too far afield. 

I don't see a problem however with gearing a high hp turbo diesel dually push vehicle to hit 150 mph in 1/2 mile or so pushing a 3000 lb vehicle.  In slop it won't happen but on hard salt it could.  Those are the only conditions an unlimited attempt like this should take place anyway.  The current SSpeed design doesn't use a transmission for space limitations.  But that's not to say we can't configure a different powertrain design w/transmission that still uses the same body geometry.  The whole point of this exercise is to arrive at a feasible design with the lowest Cd, FA, and weight possible to set an unlimited WD record. Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on September 20, 2019, 05:22:24 PM
Using push vehicles is, of course, allowed because of the high gearing of the race vehicles, in addition to not plastering the starting line members with salt and/or dirt.

I'd sure guess the the SCTA would require full race vehicle specifications for such a push truck and its driver in the case you're putting together.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on September 20, 2019, 05:28:11 PM
  In slop it won't happen but on hard salt it could.  Those are the only conditions an unlimited attempt like this should take place anyway.
Or any 300+ attempt, as recently, disastrously, demonstrated.



Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 20, 2019, 05:52:46 PM
fastest diesel pickup I see is 227 mph I guess in the last (5th) mile. 150 in the first half mile means he only picked up 75 mph in the remaining 3 1/2 miles. And he wasn't push starting anything. Especially some long very low and hard to see car. With a driver also having a hard time due to the lack of reference points to help him stay straight. I don't know how much experience you have had pushing off at a high , but much less than 150,  speed. It's not that easy. I would not accept a job pushing a 'liner at 150
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 06:11:26 PM
I'd say we'd need a push truck with gearing and torque to hit 150 max speed by the 1/2 mile mark.

The benefit of pushing to 150 by the 1/2 is the removal of any need for brakes or parachutes on the car since the resulting crash will slide/tumble to a stop around the one.

This also has the added benefit of allowing the safety equipment to be pre-staged there since the final location of the accident debris is pretty much a given.
Quote
Have you ever driven a pushee at 150 mph. A bit on the difficult scale.
DW
Quote
So all you need is a push truck that will go 150 while push starting your liner in 1/2 mile? On salt? Sounds like you need to start a new build diary. This is going to be a pretty fast pickup.

Hi All...
Good points with valid concerns, thanks for the thought provoking comments.  I agree that conventionally pushing a design like this to high speed is troublesome to say the least.  But there's not much about this design effort that's conventional is there?  So let me comment for a bit about why I think this current design is desirable over previous versions and then address the push vehicle.

Let's consider existing conditions that must be overcome for successful results.  Based on what I've read from you traction is the #1 limiting factor for record speeds.  Aerodynamic is #2, stability #3 (due in large part to limited traction), and available hp last. Please tell me if that's wrong, needs reordering or additional items...

#1: Traction is not a problem here because of low torque and 1:1 gearing.  I've eliminated the active aero flap for V.5.8 because of the change in torque characteristics over the previous 100% torque electric motor drive.  When the IC engines light up at 2200 rpm the power curve up to max rpm should be progressively strong depending on port and ignition timing, total weight, and applied power adders.  Based on IO's input I recognized that weight will be an extremely important issue in how the car performs given the new IC direct drive powertrain. 

So, I research to find the best way to affordably apply Carbon Fiber (CF) into the chassis build.  2" x .085 wall high modulus CF square tubing, bonded 3D printed titanium connectors, and bolted/bonded 1/2" multi-directional layered CF plate can be applied to form a super strong/stiff light weight space frame truss chassis.  I'll probably use the same construction technique for the drivers tub instead of the molded design as currently shown.  It's easier to build and cost less overall. 

#2:  Aerodynamically I think the current design at 4 sq.ft FA and low Cd shape is competitive compared to others I've been able to study. 

#3: Stability wise moving away from rear wheel drive to forward drive should greatly help deal with yaw problems that plague more conventional designs, especially since the current plan is to use the DF chassis layout.  The reported stability of the Salt Shark FWD car convinced me forward drive is the way to go if enough traction can be found to eliminate rear drive wheels. We may even reduced the number of drive wheels from 6 back to two using a stacked inline rotor configuration with a forward steering differential and no transmission.  We could then experiment with different diff gearing to help tune the power curve given that rotary IC engine(s) are good to 10,000 rpm max.  That would also eliminate the mechanically disconnected IC powerplants as seen in V.5.8.

#4: Push Vehicle.  Pushing this design from the rear would effectively amount to rear steering from 0 to 150 mph.  I assume everyone agrees that's the wrong approach to take.  However, given a safe alternative I would argue that push starting to somewhere in that speed range to take advantage of the direct drive platform for potential max speed is very desirable.  So here's one alternative that I believe could be safely applied.

If one were to pull this design from the front rather than push from the rear it would be inherently stable up to and beyond LSR applied power.  Knowing that we can't use a tow vehicle to start we need a new design push truck that accomplished the same result from the rear.  A conventional pick up truck isn't the best approach IMO.  We need a custrom built, horse shoe shaped vehicle that surrounds the LSR car from the rear leaving the front open for the LSR to pull away under its own power at the right rpm.

Each leg of the push "shoe" running either side of the LSR would make a "push" connection to the LSR through forward mounted booms that connect with the LSR at nose contact points on each side that effectively "push" the LSR forward up to speed.  Either upon push shoe braking or LSR power, or both, the LSR would pull way and make its run.  The push shoe would then steer off track conventionally and head to the other end.

Effectively, the push shoe truck could also act as a powered exoskeleton trailer that lifts the LSR off the track for maneuvering around the pits and turn around at the end of the track after each run.  Run a sprung dually real axle mated to a turbo diesel or even better a high torque electric motor geared to max out at the 1/2 mile marker.  Use sprung wheels at the nose of each shoe leg for steering with the shoe driver sitting wherever best serves his purpose and control of the vehicle.  Use of a light space frame with roll cage protection for the shoe driver should produce total weight of the two vehicles less than a big dually pick up truck alone.  It should be narrow enough to trailer to the race for use.  Your thoughts please.  Thanks... Terry.



Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on September 20, 2019, 06:22:12 PM
I doubt anybody would let a push go that fast any more. I pushed one of Jim Feuling's cars beyond 100 mph back in the 90's & that was some spooky $hit! Vesco were pushing their liner back in those days with a blown BBC Jeep to get the twin Offy's on boost. That was some interesting crap to watch too!
My new liner is geared for 500+ & will drive away from the line unassisted.
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: Sumner on September 20, 2019, 06:46:42 PM
....or 836 hp needed for the SSpeed design @ 350 mph; or 1639 hp @ 600 mph.

Under the common convention that it takes 8 times the HP to double the speed I think that 836 hp to run 350 would result in it taking 4212 HP to run 600. 

If you look at Tubinator's run...

https://www.youtube.com/watch?v=BdBahNZOg9o

they are running 182 at the 1/2 mile and ran an exit speed of 503.  I'd think to run 600 you'd have to be running faster than 150 at the 1/2 mile even on say a 6 mile course.  Over 300+ it is really a drag race unless you have basically a very long course.

As mentioned by you and others to have a chance to run 400+ you need almost a perfect race course/surface.  Given that I think trying to put suspension in the car is not require.  My personal feeling is that much over 250 a suspension can't begin to react to the course conditions in a matter that will make much of a difference.   The car is just going to fast for the suspension to be able to keep up with the conditions.  By the time it reacts to one condition it probably has already experience a number of others.

I'm still not comfortable with the safety of putting the driver out in front of all the wheels.  The driver will react to the feeling in his butt way faster than visually looking at some string in front of him.  I was on bad washboard gravel recently and even at 50 mph was making adjustments by that feel way before I'd be able to looking out the windshield at a piece of string.  Again go out and try it on a gravel washboard road or a snowy one and see if you are correcting by feel or sight.  With a  driver position out front you are putting the driver in a dangerous situation in my opinion.  It is hard enough when the driver is just behind the front wheels and putting him/her ahead of the front wheels just makes it all that more difficult. 

Looking at the video ....

https://www.youtube.com/watch?v=-uNRHo7XH6c

... you can see how much the Turbinator is moving around on the course and how much Dave Spangler has to drive the car.  He is looking out front but I can take a good guess he is driving by what he is feeling more than anything.  Unbelievable driving skills.  I think few people really appreciate what it takes to drive a car fast on the salt.  To help keep them safe give them all the help they can get.

Sumner
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 07:11:35 PM
I doubt anybody would let a push go that fast any more. I pushed one of Jim Feuling's cars beyond 100 mph back in the 90's & that was some spooky $hit! Vesco were pushing their liner back in those days with a blown BBC Jeep to get the twin Offy's on boost. That was some interesting crap to watch too!
My new liner is geared for 500+ & will drive away from the line unassisted.
  Sid.
Hi Sid,
I'm just speculating about 150 mph being the needed push speed based on wheel rpm @ 1:1 direct drive.  Using a steering diff, final drive gearing could be changed to take advantage of the rotor engine's max top speed of 10,000+ rpm allowing a lesser push speed to hit the take off rpm.  Going to a slightly smaller 23" wheel from 23.5 would help too. Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on September 20, 2019, 07:19:54 PM
This is starting to remind of, long, long ago, a thread where the author spent day after day trying to name the swoosch that he called a car.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 07:26:05 PM
....or 836 hp needed for the SSpeed design @ 350 mph; or 1639 hp @ 600 mph.

Under the common convention that it takes 8 times the HP to double the speed I think that 836 hp to run 350 would result in it taking 4212 HP to run 600. 

If you look at Tubinator's run...

https://www.youtube.com/watch?v=BdBahNZOg9o

they are running 182 at the 1/2 mile and ran an exit speed of 503.  I'd think to run 600 you'd have to be running faster than 150 at the 1/2 mile even on say a 6 mile course.  Over 300+ it is really a drag race unless you have basically a very long course.

As mentioned by you and others to have a chance to run 400+ you need almost a perfect race course/surface.  Given that I think trying to put suspension in the car is not require.  My personal feeling is that much over 250 a suspension can't begin to react to the course conditions in a matter that will make much of a difference.   The car is just going to fast for the suspension to be able to keep up with the conditions.  By the time it reacts to one condition it probably has already experience a number of others.

I'm still not comfortable with the safety of putting the driver out in front of all the wheels.  The driver will react to the feeling in his butt way faster than visually looking at some string in front of him.  I was on bad washboard gravel recently and even at 50 mph was making adjustments by that feel way before I'd be able to looking out the windshield at a piece of string.  Again go out and try it on a gravel washboard road or a snowy one and see if you are correcting by feel or sight.  With a  driver position out front you are putting the driver in a dangerous situation in my opinion.  It is hard enough when the driver is just behind the front wheels and putting him/her ahead of the front wheels just makes it all that more difficult. 

Looking at the video ....

https://www.youtube.com/watch?v=-uNRHo7XH6c

... you can see how much the Turbinator is moving around on the course and how much Dave Spangler has to drive the car.  He is looking out front but I can take a good guess he is driving by what he is feeling more than anything.  Unbelievable driving skills.  I think few people really appreciate what it takes to drive a car fast on the salt.  To help keep them safe give them all the help they can get.

Sumner
Hi Sumner,
I agree the 1639 hp is a bogus number.  As is the 836 in my opinion.  Very hard to estimate needed hp based on available info for aero and rolling drag formulas.  Hardly anything correlates between published info of other cars as well.  I do believe it took more than 1500 hp for the JCB car to hit 350.  2600 for the BB3 car seems more in line with their 350 record with better aero but greater weight.  Going back to 8 rotors, I think 4000 hp is the max limit for the SSpeed design study.

I'm now counting on fwd as seen in the Salt Shark to make the DF position viable for this design.  He sits ahead of the drive/steering wheels in the DF position and said the SS car was rock stable even on the bad track in August.  His and everyone else's slower speeds reflect how difficult it was to gain traction at that event.

Does anyone have info about other fwd cars (any class) and their driveability on the salt?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 07:27:42 PM
This is starting to remind of, long, long ago, a thread where the author spent day after day trying to name the swoosch that he called a car.
Hi Stan,
I did a search for "swoosch" and found nothing... tell me more about it?  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on September 20, 2019, 07:44:03 PM
Under the common convention that it takes 8 times the HP to double the speed I think that 836 hp to run 350 would result in it taking 4212 HP to run 600.
That "common convention" is HP to overcome aero drag, with the assumption that rolling resistance is relatively negligible at high speeds. Simspeed's model, if I recall, shows rolling resistance as a much larger component of overall drag. (Correct me if I'm wrong, Simspeed.)  I think he needs to defend that model, if he's basing his design upon it.

Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 20, 2019, 08:38:54 PM
Under the common convention that it takes 8 times the HP to double the speed I think that 836 hp to run 350 would result in it taking 4212 HP to run 600.
That "common convention" is HP to overcome aero drag, with the assumption that rolling resistance is relatively negligible at high speeds. Simspeed's model, if I recall, shows rolling resistance as a much larger component of overall drag. (Correct me if I'm wrong, Simspeed.)  I think he needs to defend that model, if he's basing his design upon it.
Hi Tortoise,
Yes you have it right as far as my formula goes.  I can only defend what i found and utilized based on internet research about both aero drag and rolling resistance formulas.  They were both commonly used through all the different sites I visited but rolling resistance formulas varied widely depending on associated factors.  The combined formula I used came from a site where the author cited examples from F1 sources.  However, we're finding that weight which is incorporated has a disproportional influence on the total hp needed.  Back to the drawing board I guess.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: superleggera on September 20, 2019, 10:11:35 PM
A 150mph push truck by the 1/2-mile? (and pushing a streamliner to same said speed)  Given the budget and time/construction resources, would it be best to build the push vehicle first?  Would it require SCTA safety equipment given the speed required?!?  And then only after it is validated on the salt then actually build the streamliner so dependent upon its actual functionality?

[I'm going to ignore the streamliner driver / push truck driver dynamic as that is an unknown at those speeds]

addendum:  Nice thing is you could always test the push truck on pavement given the short distances required and numerous courses available around the country to do it upon without resorting to testing at Bonneville. (and having to wait each year)  Just build something for it to push with approximate weight and four wheels for actual testing.  Thus your only variable would be the salt itself (versus pavement or concrete).
Title: Re: Simspeed UWD LSR Design Project
Post by: Doc B. on September 20, 2019, 10:47:38 PM
Quote
A 150mph push truck by the 1/2-mile? (and pushing a streamliner to same said speed)

https://youtu.be/EoTVvTTiT6w
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 21, 2019, 06:34:47 PM
A 150mph push truck by the 1/2-mile? (and pushing a streamliner to same said speed)  Given the budget and time/construction resources, would it be best to build the push vehicle first?  Would it require SCTA safety equipment given the speed required?!?  And then only after it is validated on the salt then actually build the streamliner so dependent upon its actual functionality?

[I'm going to ignore the streamliner driver / push truck driver dynamic as that is an unknown at those speeds]

addendum:  Nice thing is you could always test the push truck on pavement given the short distances required and numerous courses available around the country to do it upon without resorting to testing at Bonneville. (and having to wait each year)  Just build something for it to push with approximate weight and four wheels for actual testing.  Thus your only variable would be the salt itself (versus pavement or concrete).
Hi Super,

Excellent suggestions.  This would of course be the optimal way to develop a custom high speed push truck.  I've done a little research today to discover a much more practical way to get the car rolling using a conventional push truck and no transmission.

Many of you may already know about this but I've just learned about the QuickDrive(tm) lock up torque converter drive.  We use to couple a powerqlide with a clutch and bell housing for what essentially was a PG based clutchflite transmission.  The QuickDrive mechanism couples a torque converter to a manual transmission that locks up at the designed rpm allowing the engine to rev up like an automatic on the line before launch and then the driver shifts manually or pneumatically during the run. 

Using a QuickDrive to bring the rpm of the 8 rotor up to say a 4000 rpm stall on the converter, we should be well into the power curve where the car could be launched from conventional push truck speeds.  This would only be possible with a fwd steering diff where the bell housing/QuickDrive/diff were directly coupled in an inline arrangement.  The QuickDrive folks offer a lockup option for the converter that eliminates slippage beyond the built in stall speed.  That arrangement and swapping the diff gears would allow tuning to use the max rpm potential of the 8 rotor to hit record speed.  I'm moving on to V.5.9 to change the power train to this FWD only, QuickDrive, no trans, steering diff arrangement.  Thanks... Terry.
I
Title: Re: Simspeed UWD LSR Design Project
Post by: Beef Stew on September 21, 2019, 09:27:04 PM
This worked for me, and it may work for you.

The push-car accelerated hard off the line. At 25mph he honked, and I let-out the clutch. When I'd built-up oil pressure, I hit the mag-switch and gave it throttle. I'd pull away from the push-car at about 75 mph. This did several things. Hard initial acceleration from the line, and I was still accelerating as the engine cleaned-out and came on the cam.

Ack Attack does this. The push truck doesn't back-off, the bike-lined pulls-away  https://www.youtube.com/watch?v=DGZ29tiBNz8 Sorta like we did in the 1960s. Your 'line may be able to pull-away at less than 150 mph.


Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 01:36:21 AM
Here's the progression to V.6.0.  This version simplifies the drive train, braking, steering, and chassis into a lightweight 31'4", 4 sq.ft. FA envelop.  I haven't calculated the weight of the CF and titanium connector chassis yet but I'll eventually get the volume of the materials and calculate the weight by density for each part and piece. I'm guessing 3200 lbs total.

The CF tubing and Ti connectors will be epoxy bonded with 1/2" CF plate bolted to the connectors with stainless button hex bolts.  I haven't yet decided how best to configure the connector attachments to allow necessary maintenance access to everything but bonding the exoskeleton plates to the perimeter CF tubing and then bolting those panel assemblies to the structural framing in sections is likely the best option.  Either way this should be a strong, rigid, lightweight chassis.

As I mentioned previously the Quick Drive torque converter coupling connecting the engine(s) to the quick change diff should solve the push start issue for this direct drive powertrain.  Considering the power output capability of 8 rotors on NoS running through a common shaft, I think this combination will have plenty of grunt to pull away to speed flashing the converter to 4000 rpm and then locking up for the big top end charge.  I'm likening how this will work to the video I've seen of the Vesco turbine pulling straight through from the start line to the 5 mile marker. 

This design is a FWD only setup where the drive wheels steer with no suspension front or rear as suggested by Sumner and others.  As far as traction, I believe the front two wheels alone should be enough to put the power to a hard salt surface given the low torque power curve of the engines running through a 1:1  gear ratio for the run up to max speed. 

I've added an intake scoop given the inline arrangement of the intake ports of the stacked rotors.  I'm thinking this should not add significantly to the total FA given that air hitting the scoop opening is being suck into the engine rather than being displaced and forced to move around solid surfaces on the body.  Anyone know otherwise?  Is there a better type of scoop to use here?  Thanks for your input... Terry



Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 01:37:33 AM
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Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on September 27, 2019, 04:47:37 AM
Hi Terry,

Don "race engineer" came to help me this year from Texas and knew Team Vesco, so they left us a space to park our van and bike so we were able to see at close quarters the life of a streamliner and its crew on the flats for nearly a week...

They do have to start the turbine in the pits to do various tests... They have a mobile trolley with a number of batteries and a 40 volts (or so...) 400 amps starter to do that.

(https://i.imgur.com/LrhC7gV.jpg)

It is also used after a run to cool down the turbine by running it with fuel shut off via auxiliary batteries located in the nose, otherwise the turbine would retain too much calories within. I haven't seen how others like Speed Demon cope with these unwanted calories but they must have some independent way to circulate water for that post run cooling:

The Turbinator has front and rear suspension plus 4 hydraulic jacks so that the engine AND 2 speed drive can be tested in the pits:

(https://i.imgur.com/eLAIbAk.jpg)

As a rule, each morning they would pull off all the body panels, all held via dzeus fittings, different sizes/depth at different locations depending on local stress. Reassemble, do a run, have problems, do it again, say 4 times a day at easily 1/2 hour minimum... That's 2 hours minimum gone in a day just for the skin...

You need to simplify yours!!!!

The Turbinator also have ballast they can add or retract and move around depending on driver feedback...

(https://i.imgur.com/NOxiEsI.jpg)

Theirs are made up of lead ingots cast into Chevrolet rocker covers.

A streamliner spends a lot of time on a trailer on the roads so need some serious anchor points. Theirs are steel fittings that screw into threaded sockets welded to the frame at front (one), midriff (two) and rear (two).
The streamliner probably also travels while up on its hydraulic jacks to save expensive rubber (I forgot to ask that question!!!):

(https://i.imgur.com/tb8A0MS.jpg)

(https://i.imgur.com/mWADLve.jpg)

They also use their cockpit after a run to store the parachutes. It takes an awful long time to set them flat on the salt and roll them in the right fashion to be safely inserted in the tubes and this is done in the pits. Make sure your cockpit is big enough for that.

(https://i.imgur.com/6wYqrwv.jpg)

Lastly, you can see Dave Spangler "serpentine" teeshirt... That's water cooling while he's strapped in ready to go in a cramped space under the Salt Flats heat...

Your drgs keep impressing me!!!

Patrick

Title: Re: Simspeed UWD LSR Design Project
Post by: TD on September 27, 2019, 08:34:16 AM

I've added an intake scoop given the inline arrangement of the intake ports of the stacked rotors.  I'm thinking this should not add significantly to the total FA given that air hitting the scoop opening is being suck into the engine rather than being displaced and forced to move around solid surfaces on the body.  Anyone know otherwise?  Is there a better type of scoop to use here? 
There's an interesting discussion of air scoop design in the Goldenrod book: https://goldenrodbook.com/   Disclaimer: I have no dog in this hunt.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 11:59:49 AM

As a rule, each morning they would pull off all the body panels, all held via dzeus fittings, different sizes/depth at different locations depending on local stress. Reassemble, do a run, have problems, do it again, say 4 times a day at easily 1/2 hour minimum... That's 2 hours minimum gone in a day just for the skin...

You need to simplify yours!!!!

They also use their cockpit after a run to store the parachutes. It takes an awful long time to set them flat on the salt and roll them in the right fashion to be safely inserted in the tubes and this is done in the pits. Make sure your cockpit is big enough for that.

Hi Patrick,
Thanks for sharing the Turbinator info and pictures.  I'd enjoy watching their race week routines to see how the fastest UWD record holder goes about its business specific to their vehicle.  Also thanks for the drawings complement.

A couple of thoughts regarding your comments... The Turbinator body panels you are describing aren't structural I don't believe.  CV plating enveloping the CF tubing chassis on Simspeed are.  The method of attachment is designed for that purpose but does allow the panels to be removed for maintenance as needed.  If you watch the Speed Demon crew at the end of each run they remove body panels via screw guns acting on torx screws.  That seems to work well for them so I consider the same method viable for our CF structural plating.  The exterior body shell will likely also be fastened to the chassis using flush mounted screws.  I used Dzus fasteners on drag cars for all sorts of panel fastening needs but here I think screw fasteners are the better alternative.

Design considerations for the Simspeed cockpit are exclusively top speed related.  How and where to carry the chutes after each run is quite secondary as there are a number of alternative options available that don't compromise the primary mission.  A spent chute bag that can be hung over the tail stabilizer for the return trip to the pits or impound is one easy option that comes to mind.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 12:10:06 PM
There's an interesting discussion of air scoop design in the Goldenrod book: https://goldenrodbook.com/   Disclaimer: I have no dog in this hunt.

Hi TD,
Thanks for the link.  I've done some research on scoop design and I'll be revising the current design for something a little more aerodynamic.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: 7800ebs on September 27, 2019, 12:33:54 PM
Interesting design... so you get to be the first one to the seen of the crash, great. And assuming 7' circumference around the car body, and 500 mph,  in a pencil roll crash, you should be able to spin at about 6000 rpm... How do you stop that?  You need... Everyone needs to think about that... How do I survive a crash at speed... The salt is not smooth often.. Way too much time is spent on how to go fast, and Not enough on surviving.... Just Saying... bob


ps: think crush zones, bendable members, anti pencil designs, auto chute deployment, yaw / roll /impact switches..
Title: Re: Simspeed UWD LSR Design Project
Post by: STICK777 on September 27, 2019, 01:45:36 PM
Good thought on mentioning the likelihood of a crash.
Though it's maybe better when the car just slides and eventually pinrolls... there were many
accidents that ended with no or only little harm. Of course there were others that didn't  :-(

Now in case of the Carbiliner crash it 'might' be that the threewheeler configuration was not
favourable... in case of a crash. When a part of the car gets 'caught' by the salt it will result
in terrible distruction... Sadly that obviously happended to the Carbiliner. I sincerly hope that
Rob is on a good way to a full recovery.

@Bob: I watched the footage of your crash last year... you are one brave and lucky guy!!
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 04:35:51 PM
Interesting design... so you get to be the first one to the seen of the crash, great. And assuming 7' circumference around the car body, and 500 mph,  in a pencil roll crash, you should be able to spin at about 6000 rpm... How do you stop that?  You need... Everyone needs to think about that... How do I survive a crash at speed... The salt is not smooth often.. Way too much time is spent on how to go fast, and Not enough on surviving.... Just Saying... bob


ps: think crush zones, bendable members, anti pencil designs, auto chute deployment, yaw / roll /impact switches..

Hi Bob,
Thanks for your input. I think this is the second time you've mentioned the design being first to the scene of a crash... how have other designs such as the Nebulous Theorem series of cars dealt with that problem?  Seems like any long thin design without a tall wing structure of some sort has the potential to roll in the event yaw takes it sideways.  I might note that tire explosion or deflation appears to be high on the list of crash inducing events.  I've incorporated aluminum wheel/tires here as a preventive measure to eliminate rubber tire issues.  Also, the use of FWD only is designed to eliminate RWD induced yaw concerns in control of the car at speed.  Anything can happen of course but what other steps can you think of to help the design remain stable?

What happened to cause your violent crash at speed.  Also...quite glad as I'm sure others are that you were able to walk away from your crash.  I understand why you are a proponent of design survivability.  I appreciate your concerns.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 27, 2019, 07:14:53 PM
Here is the redesigned intake scoop.  I wonder at what mph aero compression will overpower intake vacuum?
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on September 28, 2019, 05:11:34 AM
Hi Terry,

You stated at the start that 7 rotors capacity was 4.5 litres, so I assume 8 rotors is about 5.14 litres?
Since these are Wankel engines, is that their "geometric" capacity or their "burn" capacity which, since 3 burns occur per rev, would be triple that?

Never used nitrous in me life... Since ""more"" is ""better"", where is the max quantity of liquid nitrous you can inject in a manifold before its gas expansion is too much for the rotors to accept and it reverses the flow in the manifold, preventing fresh air coming in? IE you cannot pressurize the inlet track above AP since it communicates freely with AP.

IE, would it be best to partially (if you need more nitrogen than the nitrous can give?) close the inlet manifolds upstream of the nitrous injection point as soon as you press the nitrous switch and regulate engine speed via plus/minus timing of the nitrous injection/methanol solenoid valves to get a supercharger/turbo effect?

IE, do you really need a big air scoop sticking in the wind?

I calculate the air speed through your duct entry (assumed 1 foot x 1/3rd of a foot as shown above) at 50mph at 8000rpm (approx 41m3 of air per mn) for 1 burn per rev and at 150mph for 3 burns per rev (approx 123 m3/mn of air)...

So you will get an aerodynamic disturbance around your duct entry above these speeds, whichever is right...

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 28, 2019, 04:47:38 PM
Hi Terry,

You stated at the start that 7 rotors capacity was 4.5 litres, so I assume 8 rotors is about 5.14 litres?
Since these are Wankel engines, is that their "geometric" capacity or their "burn" capacity which, since 3 burns occur per rev, would be triple that?

Never used nitrous in me life... Since ""more"" is ""better"", where is the max quantity of liquid nitrous you can inject in a manifold before its gas expansion is too much for the rotors to accept and it reverses the flow in the manifold, preventing fresh air coming in? IE you cannot pressurize the inlet track above AP since it communicates freely with AP.

IE, would it be best to partially (if you need more nitrogen than the nitrous can give?) close the inlet manifolds upstream of the nitrous injection point as soon as you press the nitrous switch and regulate engine speed via plus/minus timing of the nitrous injection/methanol solenoid valves to get a supercharger/turbo effect?

IE, do you really need a big air scoop sticking in the wind?

I calculate the air speed through your duct entry (assumed 1 foot x 1/3rd of a foot as shown above) at 50mph at 8000rpm (approx 41m3 of air per mn) for 1 burn per rev and at 150mph for 3 burns per rev (approx 123 m3/mn of air)...

So you will get an aerodynamic disturbance around your duct entry above these speeds, whichever is right...

Patrick
Hi Patrick,

Mazda rates it's two rotor engines at 1.3 liters.  So 1.3/2 = .65 *8 = 5.2 liters.  I may have also misquoted 5.14 previously.    Each rotor does produce 3 power strokes per rotor rev, but, they run on an eccentric output shaft which turns 3 times faster.  That means each rotor produces one complete power stroke per output shaft (crankshaft) rotation. 

A power stroke for a single rotor covers 90 degrees of rotor rotation which covers 270 degrees of crank rotation (90 x 3 = 270), where a single piston power stroke is 90 degrees (180 / 2 crankshaft rotations). So, where a V8 fires 4 times per crank rotation (4 * 90 = 360 total degrees combined power stroke), an 8 rotor engine fires 8 times for each rotor face that completes a full power stroke (8 x 270 = 2160 total degrees), AND, 8 times for each second face that completes 90 degrees of power stroke for each crankshaft rotation (360 - 270 = 90).  Because each of the 3 faces of a single rotor fire sequentially throughout the 360 degree "rotor" rotation cycle, when we convert rotor rotation to crank rotation we see 90 degrees of crank rotation remaining that sees 30 degrees of rotor power stroke from the next sequential face of the rotor (90 / 3 = 30).  So... 8 * 270 = 2160) + ( 8 * 90 = 720) = 2160 + 720 = 2880 total combined degrees; or 2880 / 8 = 360 degrees of crank power stroke per rotor per each crank rotation).

Although displacement per rotor face is 1/3 that of a V8 of equal total displacement (.65 / 3 = .216) vs (5.2 / 8 = .65) those 24 rotor faces (8 x 3 = 24) combined are producing 8 times more total degrees of power stroke per crank rotation than the V8.  I believe I have all that correct but with rotary engines who really knows.  :wink:

Concerning intake calculations:  Each rotor takes in .288 L of displaced air per crank rotation (.216 L @ 90 degrees (single face)) + (.072 L @ 30 degrees ( next sequential face)); totaling 2.304 L (.288 * 8) per crank rotation.  Whereas each piston of the V8 takes in .325 L of displaced air per crank rotation (.65 / 2) or 1/2 of the 4 stroke two crank rotation cycle totaling 2.6 L (.325 * 8) per crank rotation. So, we're looking at 11.5% less displaced air intake per crank rotation than a V8.  Does this make sense on the face of it?  We would have to say volumetric efficiency of a normally aspirated rotary engine is better than a 4 stroke NA piston engine given the numbers above.   

Nitrous as I understand the principle is injected via bottle pressure which instantly expands to AP in an NA environment.  The power benefit comes from the introduction of extra oxygen molecules relative to that available in natural air. Combustion heat releases oxygen from the nitrogen/oxygen compound which in turn combines with the fuel to create additional power by volume.  You may be right that less natural air is needed via the intake scoop using NOs than without, but by total volume of air consumed by any internal combustion engine over the course of a run, I don't think you can carry enough NOs on board to cover the total volume of air needed given current pressurization systems used for this application.  Also, intake scoops offer a degree of aerodynamic compression of air stacking up inside the scoop chamber depending on the speed of air contacting the scoop intake opening, size of the opening, size of the interior chamber, and volumetric efficiency of the engine at a given rpm relative to ground speed. 

I do agree that we will see an aero disturbance around the scoop opening depending on the degree of compression stacking withing the scoop.  Thanks again for your input Patrick.  Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: 7800ebs on September 28, 2019, 11:19:37 PM
 I've incorporated aluminum wheel/tires here as a preventive measure to eliminate rubber tire issues.  Also, the use of FWD only is designed to eliminate RWD induced yaw concerns in control of the car at speed. 

So what is the cf of aluminum on Salt?      cf / traction is what makes us go... and when all wheels are spinning.. what then?  Have you ever driven on salt with an aluminum wheel? Don Vesco did in early 90's as I recall.. you may need to review that idea.. if the hp can't be hooked up, all other design innovation dies... bob
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on September 29, 2019, 03:22:58 AM
And, Bob, I seem to remember most FrontWD can't accelerate as fast as a RWD due to weight transfer rear bias during acceleration and loss of front traction unless there's a few tons of bricks on top of them, never mind how good the front rubber is...!!!

The Turbinator is 4 wheel drive...

NOVIs, MILLERs and others FrontWD at Indy spring to mind...

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: 7800ebs on September 29, 2019, 12:41:03 PM
I don't think there is as much weight transfer as you may think on a long wheelbase car at Bonneville. To have any weight transfer, you must have something to provide an acceration force. It is called traction.. bob
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 29, 2019, 01:13:27 PM
I've incorporated aluminum wheel/tires here as a preventive measure to eliminate rubber tire issues.  Also, the use of FWD only is designed to eliminate RWD induced yaw concerns in control of the car at speed. 

So what is the cf of aluminum on Salt?      cf / traction is what makes us go... and when all wheels are spinning.. what then?  Have you ever driven on salt with an aluminum wheel? Don Vesco did in early 90's as I recall.. you may need to review that idea.. if the hp can't be hooked up, all other design innovation dies... bob
Hi Bob,
I've stated previously that our plan for traction is to apply the SlipNOT (tm) #2 Metal Sputter Coat Traction coating on the contact surface of the aluminum wheels. https://www.slipnot.com/what-is-slipnot/ (https://www.slipnot.com/what-is-slipnot/).  Based on what I understand of the process the sputter coating material (aluminum) is molecularly bonded to the wheel as a stippled texture that produces traction against the track surface (salt).  The coating can be applied in various thickness and texture for best results.  I would use the coating on all wheels fore and aft.  Thanks... Terry.   
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 29, 2019, 01:25:46 PM
I don't think there is as much weight transfer as you may think on a long wheelbase car at Bonneville. To have any weight transfer, you must have something to provide an acceration force. It is called traction.. bob
Traction is elusive on the salt as I understand what others have reported.  I don't see the benefit of running a car of this type on anything but the best track conditions.  Bonneville may no longer be the track of choice for unlimited wheel driven vehicles so there will have to be alternative course considerations for record attempts.

SlipNOT coated wheels would have to be tested on the salt to determine their viability for this design effort.  I would propose to supply an existing team with coated wheels for testing before committing funding for this project.  The results of those tests would help to determine whether or not 2 or 4 drive wheels should be incorporated into the Simspeed design.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: 7800ebs on September 29, 2019, 02:09:29 PM
Soooo..  machine some aluminum with radius desired. Get a fish scale, add 100 lbs to said aluminum.  Pull it across the salt .  Read scale.  If it takes 20 lbs to move it across salt.  Cf is .2..  address issues .. set record's... Become hero.. this stuff is easy... Bob
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 29, 2019, 02:16:45 PM
Soooo..  machine some aluminum with radius desired. Get a fish scale, add 100 lbs to said aluminum.  Pull it across the salt .  Read scale.  If it takes 20 lbs to move it across salt.  Cf is .2..  address issues .. set record's... Become hero.. this stuff is easy... Bob
Why the sarcasm Bob? SlipNOT is a commercial coating process designed to provide traction to slick metal surfaces.  What's not to understand about how it could be applied for this application? BTW...In my estimation a Hero is someone who gives their all for the benefit of others in need...not accomplishment for their own benefit.
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 29, 2019, 02:23:18 PM
For a few years in the 70s I worked in a Plasma spray shop. Which I guess is this process. Or wire spray. And yes it is granular in varying degrees. And we were not trying to make nonslip surfaces. But it still is about the same surface as coarse sandpaper for the really coarse stuff. I would be surprised if it grips salt. Maybe if it is near concrete hard. When do you want to try your test wheels?
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 29, 2019, 02:37:14 PM
For a few years in the 70s I worked in a Plasma spray shop. Which I guess is this process. Or wire spray. And yes it is granular in varying degrees. And we were not trying to make nonslip surfaces. But it still is about the same surface as coarse sandpaper for the really coarse stuff. I would be surprised if it grips salt. Maybe if it is near concrete hard. When do you want to try your test wheels?
Hi Rich,
https://www.slipnot.com/what-is-slipnot/#!metal-surface-options (https://www.slipnot.com/what-is-slipnot/#!metal-surface-options) From appearances the coating looks to be like course sand paper.  The mfg sites Underwriter Laboratory label as slip resistrant.  The minimum friction coefficient is listed as 0.8.  I don't see why it wouldn't grip the salt as well and any other tire given the same contact patch.  Thanks... Terry.

Not anytime soon on the test wheels Rich.  More likely we'd pay for the coating applied to someone else's drive wheels to see how well it worked for them. 
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 29, 2019, 02:47:25 PM
Here's a colored cross section of the 3 piece wheel design I'm using for this study.
Title: Re: Simspeed UWD LSR Design Project
Post by: 7800ebs on September 29, 2019, 03:30:19 PM
Interesting product, it's designed to coat metal so you won't slip on metal. Stairs, road plates, etc..  I'm guessing that tires on road work plates are rubber. And shoes on metal steps are rubber like. So the product is probably a great surface for tires to run on. I'm a bit troubled with it being the tire. A small test section should be created by you, and tested. I personally believe you need contact patch to make any of this work. My partner who is very involved in the big show explained it perfectly. In drag racing tires need shear strength of the rubber to accelerate. That's why the large slicks. At Bonneville we are dealing with MOST often the shear strength of the salt. And that is why solid wheels don't work, contact patch. It's that simple. bob
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on September 29, 2019, 04:15:09 PM
Rubber tires, even at high pressure deflect into a contact patch, metal doesn't. Therefore I would at least design your tires flat across with rounded edges rather than convex in cross section so there is at least some contact patch. I tend to agree with the others that rubber is required on the drive wheels.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 29, 2019, 04:39:05 PM
Here's a colored cross section of the 3 piece wheel design I'm using for this study.
But no one has wheels like yours to apply the coating to so that you can test it. I think that Bob's idea of making a small test piece might be best. I'm not sure if this is a serious discussion about a car that is proposed. Or Blue Sky thoughts on the possibilitys out there in LSR. I am sure the slipnot people can supply you with a test wheel if you send them something to spray. It needn't be a accurate model of your planned wheel. Just some thing you could use to test CF on the salt with. Could save an awful lot of time and money if it's not going to work.   
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on September 29, 2019, 04:46:12 PM
Chet Herbert (my hero, by the way) had a car with aluminum wheels that had a very large contact patch -- the belly pan if I remember correctly.
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 29, 2019, 05:39:03 PM
It seems to me, that even as an intellectual exercise you should prove your foundation before wasting time on things that don't work. To that end I propose that you build a test device for your wheels. I think a scooter or snowmobile would be a good starting point. Something with a centrifugal clutch. If you begin with a snowmobile you will need to modify it to accept a rear tire instead of the track. Either way you get a scooter tire and wheel  and machine a piece of aluminum to fit in the same place as the tire. Send it off to be slipnoted. Then take it to Speedweek with a scale and attach it to a car or truck and see if it will pull as well as the rubber tire. Or at least well enough to give you the acceleration you need. And you would have a scooter to ride around the pits to see what other people are doing.
Title: Re: Simspeed UWD LSR Design Project
Post by: ronnieroadster on September 29, 2019, 06:09:52 PM
It seems to me, that even as an intellectual exercise you should prove your foundation before wasting time on things that don't work. To that end I propose that you build a test device for your wheels. I think a scooter or snowmobile would be a good starting point. Something with a centrifugal clutch. If you begin with a snowmobile you will need to modify it to accept a rear tire instead of the track. Either way you get a scooter tire and wheel  and machine a piece of aluminum to fit in the same place as the tire. Send it off to be slipnoted. Then take it to Speedweek with a scale and attach it to a car or truck and see if it will pull as well as the rubber tire. Or at least well enough to give you the acceleration you need. And you would have a scooter to ride around the pits to see what other people are doing.

   You forgot to mention the scooter will need the proper BLM permit .
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on September 29, 2019, 06:43:01 PM
There's always Lake Gardiner
Title: Re: Simspeed UWD LSR Design Project
Post by: Elmo Rodge on September 29, 2019, 07:19:35 PM
Just put a propeller on it. Problem solved.  :cheers:
Wayno
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on September 29, 2019, 07:38:12 PM
Winner, winner, chicken dinner!!!
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 01:39:26 AM
Interesting product, it's designed to coat metal so you won't slip on metal. Stairs, road plates, etc..  I'm guessing that tires on road work plates are rubber. And shoes on metal steps are rubber like. So the product is probably a great surface for tires to run on. I'm a bit troubled with it being the tire. A small test section should be created by you, and tested. I personally believe you need contact patch to make any of this work. My partner who is very involved in the big show explained it perfectly. In drag racing tires need shear strength of the rubber to accelerate. That's why the large slicks. At Bonneville we are dealing with MOST often the shear strength of the salt. And that is why solid wheels don't work, contact patch. It's that simple. bob
The contact patch of the wheel design I'm showing would be very similar to that of a rubber LSR tire.  The wheel would depress into the salt under weight such that the upward curve of the body and side radii would bear against the salt for added contact.  The side radii would also help to add directional stability that would not be present with a flat surface running side to side.  That was the intention anyway when the design was created.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 01:40:46 AM
Rubber tires, even at high pressure deflect into a contact patch, metal doesn't. Therefore I would at least design your tires flat across with rounded edges rather than convex in cross section so there is at least some contact patch. I tend to agree with the others that rubber is required on the drive wheels.

Pete
Hey Pete... See my comment to Bob above about contact patch.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 01:44:53 AM
Here's a colored cross section of the 3 piece wheel design I'm using for this study.
But no one has wheels like yours to apply the coating to so that you can test it. I think that Bob's idea of making a small test piece might be best. I'm not sure if this is a serious discussion about a car that is proposed. Or Blue Sky thoughts on the possibilitys out there in LSR. I am sure the slipnot people can supply you with a test wheel if you send them something to spray. It needn't be a accurate model of your planned wheel. Just some thing you could use to test CF on the salt with. Could save an awful lot of time and money if it's not going to work.
I agree that testing must be done Rich.  My comment about coating someone else's wheels was aimed at simply testing to see if the SlipNOT product would offer usable traction on any aluminum wheel.  Obviously, wheels specific to the Simspeed design would have to be constructed and tested independently if the product showed promise in a nonspecific wheel test.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 01:47:14 AM
It seems to me, that even as an intellectual exercise you should prove your foundation before wasting time on things that don't work. To that end I propose that you build a test device for your wheels. I think a scooter or snowmobile would be a good starting point. Something with a centrifugal clutch. If you begin with a snowmobile you will need to modify it to accept a rear tire instead of the track. Either way you get a scooter tire and wheel  and machine a piece of aluminum to fit in the same place as the tire. Send it off to be slipnoted. Then take it to Speedweek with a scale and attach it to a car or truck and see if it will pull as well as the rubber tire. Or at least well enough to give you the acceleration you need. And you would have a scooter to ride around the pits to see what other people are doing.

I think that's a good idea Rich.  I'll explore it and see what I can come up with that would fit the bill.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on September 30, 2019, 02:09:13 AM
Interesting product, it's designed to coat metal so you won't slip on metal. Stairs, road plates, etc..  I'm guessing that tires on road work plates are rubber. And shoes on metal steps are rubber like. So the product is probably a great surface for tires to run on. I'm a bit troubled with it being the tire. A small test section should be created by you, and tested. I personally believe you need contact patch to make any of this work. My partner who is very involved in the big show explained it perfectly. In drag racing tires need shear strength of the rubber to accelerate. That's why the large slicks. At Bonneville we are dealing with MOST often the shear strength of the salt. And that is why solid wheels don't work, contact patch. It's that simple. bob
The contact patch of the wheel design I'm showing would be very similar to that of a rubber LSR tire.  The wheel would depress into the salt under weight such that the upward curve of the body and side radii would bear against the salt for added contact.  The side radii would also help to add directional stability that would not be present with a flat surface running side to side.  That was the intention anyway when the design was created.  Thanks... Terry



Terry, look at 1.N "course damage" in the SCTA rule book.

It addresses non-pneumatic wheel/tire combinations and damage to the course.

The "depress into the salt under weight" may be an issue.

Not trying to be negative, just helpful.

Carry on,  Don
Title: Re: Simspeed UWD LSR Design Project
Post by: Peter Jack on September 30, 2019, 06:38:48 AM
Terry, if your design works as you think and I have little reason to think it won't, you will be unwelcome at any meet because you'll kill the track really quickly. You'll be automatically breaking up the surface so will have to move the track over every run to maintain traction.

Pete
Title: Re: Simspeed UWD LSR Design Project
Post by: jacksoni on September 30, 2019, 07:55:39 AM

Couple of thoughts. Considering the state of the track at speedweek this year, everybody would have been d/q'd for track damage.... in my first run it was,, "krikey, look at the ruts" at speed in the 2. :dhorse:

Being Bonneville racers all and running under SCTA rules, there are a lot of concerns with Simspeed's design and does it fit those rules. In many cases, no, and this has been pointed out many times. At this point it is a design study with hopes at some time it may become a real car, at least that is my take. When it becomes reality the locale of an attempt will need to be worked out. May be at Bonneville, maybe someplace else, and if there is a sanctioning body its rules will need to be considered. Meantime there is a lot of designing to be done to get a more or less workable design. He has come up with a lot of neat ideas. Some may work, others not.  Lets leave the rule nitpicking till later. JMO
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on September 30, 2019, 10:25:45 AM
Yes, same here, this discussion might help me better design my next Bonneville bike, so argumentation is good...

(https://i.imgur.com/vDFhUHs.jpg)

(preliminaries, I'm not up to design it proper yet, although engine is done and dusted!!!)

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 07:06:46 PM

Terry, look at 1.N "course damage" in the SCTA rule book.
It addresses non-pneumatic wheel/tire combinations and damage to the course.
The "depress into the salt under weight" may be an issue.
Not trying to be negative, just helpful.

Carry on,  Don
Quote
Terry, if your design works as you think and I have little reason to think it won't, you will be unwelcome at any meet because you'll kill the track really quickly. You'll be automatically breaking up the surface so will have to move the track over every run to maintain traction.

Pete
Quote
Couple of thoughts. Considering the state of the track at speedweek this year, everybody would have been d/q'd for track damage.... in my first run it was,, "krikey, look at the ruts" at speed in the 2. :dhorse:

Being Bonneville racers all and running under SCTA rules, there are a lot of concerns with Simspeed's design and does it fit those rules. In many cases, no, and this has been pointed out many times. At this point it is a design study with hopes at some time it may become a real car, at least that is my take. When it becomes reality the locale of an attempt will need to be worked out. May be at Bonneville, maybe someplace else, and if there is a sanctioning body its rules will need to be considered. Meantime there is a lot of designing to be done to get a more or less workable design. He has come up with a lot of neat ideas. Some may work, others not.  Lets leave the rule nitpicking till later. JMO
Thanks Guys,
We are attempting to arrive at a specific design that will eventually be processed to include design and engineering of every part and component that makes up the whole.  We all agree the wheels are perhaps the most crucial components in the design to reach the intended speeds.  For now we're just have a working concept that may or may not resemble the final design.  The overall dimensions of the wheels however will likely remain the same.   With the size and profile shown I don't believe these wheels will have any more impact on the salt than conventional LSR tires.  As mentioned where the car will run for records is likely to be somewhere other than Bonneville given its current and potentially future condition.  So I'm not concerned about salt damage related rules at this stage.  That may change in the future but frankly I don't see rubber tires advancing the unlimited records much beyond today's marks.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on September 30, 2019, 07:12:33 PM
Yes, same here, this discussion might help me better design my next Bonneville bike, so argumentation is good...

(https://i.imgur.com/vDFhUHs.jpg)

(preliminaries, I'm not up to design it proper yet, although engine is done and dusted!!!)

Patrick

Hi Patrick,
I like your design.  2D drawings a essential to good development in my opinion.  3D helps to visualize the design for me and that's why I use it at this stage.  When it comes time to fit the parts and pieces for the prototype stage 2D will convey the necessary information to the machinist and  fabricators for construction.  Thanks... Terry. 
Title: Re: Simspeed UWD LSR Design Project
Post by: superleggera on September 30, 2019, 11:28:33 PM
One more thing to think about amongst everything else:   For non-USA events, what size of an International spec shipping container will be required for the streamliner and its salt bed transport trailer / service bench and the associated cost to ship it at a given weight with basic gear / tools? 
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on October 01, 2019, 01:35:08 AM
In one word, a big container!!!

Since I come from over the pond, my preliminary design is in 2 halves, with 2 bulkheads bolting together in front of the engine = smaller crate...

Freight cost is a function of weight and dimms...

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 01, 2019, 11:14:41 AM
One more thing to think about amongst everything else:   For non-USA events, what size of an International spec shipping container will be required for the streamliner and its salt bed transport trailer / service bench and the associated cost to ship it at a given weight with basic gear / tools?
Hi Super,

Yes I did that.  Scaled the car, carrier, and accessories for a standard 40' shipping container.  Since we will be concentrating on the one record there not much in the way of additional engines and such like we see with the Speed Demon team.  I think the one container can carry what will be needed.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on October 01, 2019, 12:02:14 PM
frankly I don't see rubber tires advancing the unlimited records much beyond today's marks.  Thanks... Terry.
You wouldn't need to go much beyond today's speeds to have a VERY big impact. First LSR over 500 would get some attention. Rubber tires would remove an unknown.  Your design would still have more than enough unknowns.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 01:16:10 AM
frankly I don't see rubber tires advancing the unlimited records much beyond today's marks.  Thanks... Terry.
You wouldn't need to go much beyond today's speeds to have a VERY big impact. First LSR over 500 would get some attention. Rubber tires would remove an unknown.  Your design would still have more than enough unknowns.
Hi Tortoise,
As true as I believe your statement to be, rubber tires are a big liability in my opinion as we've witnessed for decades and especially in recent months.  From a safety standpoint alone aluminum wheels should become the standard rolling stock for every ultra fast vehicle.  Technology will deliver traction to make metal LSR wheels practical.  I think that will happen sooner than later so that's what my design will incorporate.  If I could race this design today I wouldn't attempt it on rubber tires.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:12:18 AM
As I continue my research of all things related to this project, I revisited the Liquid Piston rotary engine project for an update.  Carefully studying their literature I discovered that they have built diesel engines of a displacement comparable to the Maza 13b engines.  Their diesel design uses a single rotor displacing 1.37 liters whereas Mazda's 2 rotor displaces 1.3 liters.  Although LP's 1.37 liter is a diesel it uses the same technology as their gasoline engine with a replaceable combustion chamber that allows for higher compression ratios for the diesel pressure fired cycle.  What is important to the Simspeed project is the manner in which the LP rotors can be stacked similar to a 13b 4 rotor with the same overall exterior dimensions in terms of height and width.  Allowing that a LP 4 rotor has the same relative displacement of a 13b 8 rotor.  The overall length of the V.6.0 design can be reduced to 29' keeping the same exterior body geometry.

What's really cool about the LP rotary engine is it's much greater efficiency than the Mazda rotary engine.  Compression ratios can be optimized with better sealing and less fuel and oil consumption.  Both engines have a triangle rotor that fires 3 times for each rotor revolution.  But the LP engine's crankshaft is geared 3:2 whereas the Mazda is 3:1.  The LP crankshaft sees 1.5 power stroke per each rotor revolution whereas the Mazda's sees only 1.33.  The LP clearly has the greater power density from that feature alone.  Apex seals in the rotor tips are a issue for the 13b where the LP's perimeter seals are fixed in the housing with direct oiling provided through housing oil channels.  The LP is a constant volume design with over expansion of the combustion cycle where the Mazda bleeds combustion expansion across the exhaust opening event wasting some measure of power.  My knowledge of such things is limited but I know enough to be able to follow the logic of why the LP design has numerous benefits the Mazda 13b does not.

So...based on the information LP provided I was able to duplicate their 1.37 rotor displacement to produce a 4 rotor model that can be fitted to the Simspeed v.6.0 chassis.  Having done so I'm calling this V.6.1 which has the same hp potential with better packaging and shorter overall dimensions.  The intake and exhaust layouts are my own design but rely on LP's own internal geometry that allows for side port gas flows through the rotor rather than peripheral porting as is common with 13b race engines.  This porting can be flipped as shown in the drawings to allow alternating intake/exhaust routing through the divider housings.  So here we have an exhaust header for each of the 12 combustion chambers and 4 shared intake ports for the 4 rotors that all run on a common eccentric/crank shaft.

Yes this is an experimental engine design that LP isn't selling to the public.  But what about the marketing benefit of breaking the ultimate wheel driven land speed record with their new engine design.  What about the diesel LSR?  Same engine essentially, same slick car, running for a 350 mph record.  Go for the diesel record first and then the UWD LSR on methanol.  I think there's potential there to put together a sponsor package that brings the best engineering, equipment, and funding to the project.  I'd love to hear your thoughts.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:14:12 AM
10 drawings total.  Can only post one here for size reasons.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:19:12 AM
More...
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:20:06 AM
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Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:20:29 AM
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Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 02:25:37 AM
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Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on October 05, 2019, 04:25:59 AM
Norton proper Wankel twin rotor engine had its inlets via the rotors... Didn't save them...
 
Apart from winning a few races on the Isle of Man TT in a ""favourable"" category, it went nowhere...

Not enough sales = high costs = bankruptcy down the line...

LP cost of $30,000 for a 70cc, just imagine what it will cost you for one big rotor, never mind the debugging and engineering costs to reliably link 6 together plus all the hardware around!!!

I work in the field of water treatment... Every year, most Utilities Big Boys spent huge amounts on various ""pie in the sky"" projects in the knowledge that forty nine and a half will fail miserably BUT maybe half of one can be made to work at huge cost and will give them an edge in 10 years time over their competitors... It's called R&D...

This LP stuff looks very much R&D to me  :-D... And tax deductible for those that keep LP alive via their investment, otherwise no progress cause there's no way it would get done.

Good luck to you on the tax deductible bit!!!

At one stage in your study, you'll have to stop firing with all barrels in all directions and focus on what's important to you and what will have to come 1st... Aero?, power?, traction?, packaging?... Then admit that the 2nd, 3rd, etc.. will have to be bog std so you can concentrate time, effort and most of the cost on the 1st goal.Then once proved, go to 2nd item on the list, etc...

I don't know when the Summers Brothers started their Bonneville career, but it was in the fifties... Then at least ten years of high/hard graft to get to the point where they astonished the world and this writer then aged 15...

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Sumner on October 05, 2019, 08:22:22 AM
......At one stage in your study, you'll have to stop firing with all barrels in all directions and focus on what's important to you and what will have to come 1st... Aero?, power?, traction?, packaging?... Then admit that the 2nd, 3rd, etc.. will have to be bog std so you can concentrate time, effort and most of the cost on the 1st goal.Then once proved, go to 2nd item on the list, etc...

I don't know when the Summers Brothers started their Bonneville career, but it was in the fifties... Then at least ten years of high/hard graft to get to the point where they astonished the world and this writer then aged 15...

Patrick

Agreed....it has to this point taken years in most cases to get a really fast car sorted out and that has been using methods pretty much already proven to work.  The  opportunities to actually run a car are so limited due to weather, track availability and track surface conditions.  Unfortunately you either have to have the money yourself to do it or the experience and track record with proven equipment to attract sponsorship and landspeed racing just hasn't attracted much in the way of reliable major sponsorship over the past 20-30 years in my memory.  The general public has no real interest.  A car goes 600 and they read a 2 paragraph story and say cool and that is the end of that.  Doesn't sell much product for the sponsor.

I never had the money to build a competitive engine but had a plan to build the car, run it with a less than an optimal engine to obtain a base line for the car.  If the car proved to be fast with less hp than existing cars then maybe someone with more money that didn't have the time to build a car would come aboard and we could go for a record together.  In my case the years went by involved in other fun interests and I find myself at 75 with a partially completed car that is far from proven and probably won't be.

My suggestion is try and go down Patrick's suggested road.  Finalize your chassis and body and start building the car.  Put a conventional engine in it with know HP.  Run the car and see how fast it goes.  Then you will have a good idea of the cars Cd and the HP needed to run a certain speed and can start extrapolating to see what the car might run with an engine/power-train of your dreams.  A number of very successful land speed racers have taken this route.  There are so many aspects to being successful on the salt and the car and engine are just part of the equation.

You could cheaply do some things now.  For instance...

(http://1fatgmc.com/car/misc-pics-1/Simspeed-2.jpg)

.... take your drawing for the driver's compartment and build it out of either wood or PVC components and see if it is practical and the driver can actually get in and out of it with a driver's suit and helmet on.  I started that way and ...

http://purplesagetradingpost.com/sumner/bvillecar/construction%20page-15.html

 .... then made changes to make my design practical.  Then replaced the wood with steel.

There are things you could get started on right now before letting the years slip away like I did  :x.  Get started and have fun with it,

Sumner
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 05, 2019, 12:10:29 PM
Do I understand that this has gone from 7 randomly placed wheels to four? One on each corner? With quick change drives? You need room to get to the QC units or they are not so QC, And I thought you needed all those drive wheels for traction. I like the old car better.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 12:32:56 PM
Norton proper Wankel twin rotor engine had its inlets via the rotors... Didn't save them...
 
Apart from winning a few races on the Isle of Man TT in a ""favourable"" category, it went nowhere...

Not enough sales = high costs = bankruptcy down the line...

LP cost of $30,000 for a 70cc, just imagine what it will cost you for one big rotor, never mind the debugging and engineering costs to reliably link 6 together plus all the hardware around!!!

This LP stuff looks very much R&D to me  :-D... And tax deductible for those that keep LP alive via their investment, otherwise no progress cause there's no way it would get done.

Patrick
Hi Patrick,

LP has contracted with DARPA to develop jet fuel powered drone engines using this technology.  The power to weight ratio is pretty amazing.  So yes this is R&D but with government contracts to support their work along with investor backing.  Everything costs money that I don't have so I'm looking at options that can be targeted for possible backing/sponsorship for the right team of racers.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 12:52:56 PM
Agreed....it has to this point taken years in most cases to get a really fast car sorted out and that has been using methods pretty much already proven to work.  The  opportunities to actually run a car are so limited due to weather, track availability and track surface conditions.  Unfortunately you either have to have the money yourself to do it or the experience and track record with proven equipment to attract sponsorship and landspeed racing just hasn't attracted much in the way of reliable major sponsorship over the past 20-30 years in my memory.  The general public has no real interest.  A car goes 600 and they read a 2 paragraph story and say cool and that is the end of that.  Doesn't sell much product for the sponsor.

Sumner
Hi Sumner,
All valid points and I recognize the validity of your approach...for a younger man.  Frankly, that route isn't feasible for me at my age and finances.  What I'm doing here is exploring concepts looking for one that has the potential to hit record speeds.  If I land on the right technical solution that can be packaged and promoted for funding, backed by a team of experienced and accomplished racers, then we'll see about approaching the right business/money people who can benefit most from the promotional aspects of a record setting venture.  As you said correctly, sponsor funding for LSR teams is rare in this day and age.  That's not to say that money can't be found given the right motivation for the right people.  The Liquid Piston people could be just such an organization given their product line and long term business aspirations.  Having LSR record(s) to promote their marketing efforts when that day arrives could be a huge feather under their corporate belt.  Designing a car with record setting potential around their engine products could be one way to get our team's collective foot in the door for part or full sponsorship in conjunctions with other supporting mfgs and business interests.  For now we're working to arrive at a competitive design...from that point forward we'll be looking for business opportunities for a JV effort.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 01:16:53 PM
Do I understand that this has gone from 7 randomly placed wheels to four? One on each corner? With quick change drives? You need room to get to the QC units or they are not so QC, And I thought you needed all those drive wheels for traction. I like the old car better.
Hi Rich,
The 7 wheel placement wasn't so random even though it might have looked that way.  We scrapped that design for several reasons, mainly because there was no direct mechanical connection between all the drive wheels.  It helped with traction but after reading the feedback I realized traction wasn't the biggest issue given the low torque power curve of the engines using a 1:1 direct drive train which was a necessity for the IC wheel engine concept.

Here we're still using the 1:1 direct drive but all the rotors are running through a common crankshaft using a Quick Drive (tm) torque coupling to a QC steering differential so we can run engine rpm up into the power curve for launch with a standard push truck.  Because we're launching with a 1:1 gear ratio and a slipping torque converter, we're not hitting the wheels with excess power down low where traction is typically most needed.  Also with this configuration the car will be much lighter that previously planned helping the engine to power the car to speed.  If we can apply power through the FWD alone we can negate yaw because the real wheels will strongly track the front with rearward Cp helping to keep the back of the car in line.  Whether two drive wheels will be sufficient for record speed is unknown but there are other cars using two wheel rear drives successfully.  With this design I think it has a chance.  We can always add a second steering differential giving 4 wheel FWD capability to the car.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 05, 2019, 02:38:02 PM
I was joking with the "Random".  If a car like this was to be built I believe the builder would be foolish not to use all the weight for traction. Turbinator uses 4WD. What ever a car like this looks like it needs to accelerate hard. And I doubt the wheels you envision provide as much bite as it will need. At least plan on using all of them.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 05, 2019, 04:13:13 PM
I was joking with the "Random".  If a car like this was to be built I believe the builder would be foolish not to use all the weight for traction. Turbinator uses 4WD. What ever a car like this looks like it needs to accelerate hard. And I doubt the wheels you envision provide as much bite as it will need. At least plan on using all of them.
Without the electric motor drives there's no good way to get mechanically linked IC power back to the real wheels in this small body envelop.  We could split the engine into 2 two rotors, one fore one aft, but that shifts the weight bias toward the rear which I'm not inclined to do given the DIF position this design needs to keep the FA below 4 sq.ft.  I've listened to what everyone has said about DIF driver feel, so I think RWD here is something to avoid.  I'd feel more comfortable with 4 front drive wheels.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 05, 2019, 04:45:54 PM
A hydraulic pump and motor doesn't take up much room. But the oil tank might be to big to go anywhere. Have you considered exhaust augmentation? Worked for Convair. Or look up Curtis-Wright 3350 Turbo compound engines. We had them when I started at United. Not for your car. But there have been aircraft that flew using a piston engine as the gas generator for a turbine that drove the prop. In theory the power loss is almost nil. And pipes are easy and cheap to run. Also you might think about a Jato assist for starting the run. Some rocket that is discarded after burn out at hopefully 150 mph. Might be easier that a really fast push truck.
Title: Re: Simspeed UWD LSR Design Project
Post by: manta22 on October 05, 2019, 05:38:55 PM
Rich: "Some rocket that is discarded after burn out..."

Advice- don't stand down range!   :?
Title: Re: Simspeed UWD LSR Design Project
Post by: Sumner on October 08, 2019, 12:04:20 PM
..  I've listened to what everyone has said about DIF driver feel...

Another thought on DIF here at about the 12 minute 10 second point from someone who has gone over 600 ...

https://www.youtube.com/watch?v=8jDB84M8zXU

Sumner
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 24, 2019, 04:28:59 PM
Here's my concept on an idea for sucker technology for LSR cars posed by Tortoise over on the Pan Skirts thread.  It involves use of a jet boat pump to suck air from under the body bounded by pan skirts for a vacuum seal.  It's designed to work much like the Chaparral sucker car back in the 60's to pull air out from under the skirted area.  The suction created by the pump would help to add downforce on the wheels for better traction.  Your thoughts...  Thanks, Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 24, 2019, 04:29:34 PM
More images...
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on October 24, 2019, 05:32:29 PM
It's driven off the crankshaft, right? Wouldn't you want something controllable? Enough downforce at low speed/rpm could create too much at high speed.
Title: Re: Simspeed UWD LSR Design Project
Post by: Dynoroom on October 24, 2019, 05:48:51 PM
Salt is not pavement...
Title: Re: Simspeed UWD LSR Design Project
Post by: dw230 on October 24, 2019, 06:47:28 PM
Your alum drive wheels currently have 0 traction.

DW
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 25, 2019, 05:04:22 AM
It's driven off the crankshaft, right? Wouldn't you want something controllable? Enough downforce at low speed/rpm could create too much at high speed.
Hi Tortoise,
Yes, like a jet boat the pump is directly driven off the engine crankshaft...or in the case of a rotary engine the eccentric shaft.  If control of the downforce effect proved to be desirable then something as simple as a port or flap could be opened to reduce the vacuum load and lessen or eliminate the surface suction.  When we read about really fast cars where wheel speed at 400 to 500 mph exceeds ground speed by 100 mph or more, then I doubt this system would ever create too much downforce at high speed.  Achieving desirable levels of downforce at low speed would be more difficult given that vacuum efficiency at lower engine rpm would likely be less than optimum.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 25, 2019, 05:06:45 AM
Salt is not pavement...
Hi Dynoroom,
Well that's a given I believe we can all agree on.  But do tell how you believe the differences would impact the effectiveness of a sucker system like this for LSR cars?  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 25, 2019, 05:11:55 AM
Your alum drive wheels currently have 0 traction.

DW
Hi DW,
We have discussed this issue previously.  The solution I believe lies in SlipNot (tm) sputter coating that bonds molten aluminum spray onto the contact surface of the aluminum wheels.  The random pattern of the applied coating provides a .80 traction coefficient as stated by the mfg.  Whether such a coating for aluminum wheel/tires will work on the salt will have to be tested before development of this vehicle design would be pursued.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 25, 2019, 09:27:59 AM
Salt is not pavement...
Hi Dynoroom,
Well that's a given I believe we can all agree on.  But do tell how you believe the differences would impact the effectiveness of a sucker system like this for LSR cars?  Thanks... Terry.
I think testing is warranted to find if this would suck the car down or the salt up. I think the salt is going to be the first to go. I liked it better with all the wheels.
Title: Re: Simspeed UWD LSR Design Project
Post by: Dynoroom on October 25, 2019, 09:39:17 AM
Salt is not pavement...
Hi Dynoroom,
Well that's a given I believe we can all agree on.  But do tell how you believe the differences would impact the effectiveness of a sucker system like this for LSR cars?  Thanks... Terry.

Running by yourself no problem. The process will work in my view.
Running at an event, well, lets just say you better bring some pepper to go with the salt your spraying on everyone & everything.
You might also notice that the wheel wells on streamliners fill up with salt & need to be scraped off before the next run. Might be tricky in you jet pump.
Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on October 25, 2019, 11:40:07 AM
Your alum drive wheels currently have 0 traction.

DW
& the big vacuum cleaner will suck salt, I hear course damage. It's not going to create much negative pressure when it's pulling the surface up.
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: thefrenchowl on October 26, 2019, 05:54:19 AM
Hi Terry,

Looking at your pan without any skirts, the air displacement speed of the sucking device  will have to be higher than the speed of the streamliner to generate any vaccum...

By my quick calculations, a streamliner 10 m long x 1 m wide and sitting 5cm off the ground has 0.5 cubic meter of air underneath.

This streamliner needs to move 10 meters to replace completely that volume of air.
So say it travels at 10 meters per second, 22.37mph, so in 1mn it will displace 18.65 cubic meters of air.
WE can then derive a ratio of air to speed ratio: 0.83.
Speed x ratio tells you how much air you have to displace 1st before generating any vacuum:

600mph * 0.83 = 500 cubic meters per mn

I know just enough about entropy to know air will be also gushing from the sides to replace the air displaced, but don't know if max air speed will be enough to totally replace the air moved and keep ATM under the car.

A vacuum might be created just by the speed of the car and the inability of the surrounding air to refill the space underneath the car above an unknown "balance" speed.

Has anyone fitted pressure or vacuum sensors underneath their streamliner to collect data?

Patrick
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 26, 2019, 08:44:37 AM
Running by yourself no problem. The process will work in my view.
Running at an event, well, lets just say you better bring some pepper to go with the salt your spraying on everyone & everything.
You might also notice that the wheel wells on streamliners fill up with salt & need to be scraped off before the next run. Might be tricky in you jet pump.
Salt build up in the impeller could be a problem for sure.  For a project of this type I don't think running on anything but ideal track conditions is feasible.  This wouldn't be a club car that runs annually regardless of track conditions.  The high salt flats in Bolivia would likely be the only place to run in anger.  Low speed runs at Bonneville for systems tests would be the most likely scenario in the US.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 26, 2019, 08:48:30 AM
Your alum drive wheels currently have 0 traction.

DW
& the big vacuum cleaner will suck salt, I hear course damage. It's not going to create much negative pressure when it's pulling the surface up.
  Sid.
Hi Sid,
Yes if it pulls up the salt in chunks then its no good in this form.  So long as the skirt seal was adequate pulling the salt up wouldn't it of itself negate the creation of negative pressure given that there's always something underneath to pull against if it's solid.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 26, 2019, 09:48:04 AM
Hi Terry,

Looking at your pan without any skirts, the air displacement speed of the sucking device  will have to be higher than the speed of the streamliner to generate any vaccum...

By my quick calculations, a streamliner 10 m long x 1 m wide and sitting 5cm off the ground has 0.5 cubic meter of air underneath.

This streamliner needs to move 10 meters to replace completely that volume of air.
So say it travels at 10 meters per second, 22.37mph, so in 1mn it will displace 18.65 cubic meters of air.
WE can then derive a ratio of air to speed ratio: 0.83.
Speed x ratio tells you how much air you have to displace 1st before generating any vacuum:

600mph * 0.83 = 500 cubic meters per mn

I know just enough about entropy to know air will be also gushing from the sides to replace the air displaced, but don't know if max air speed will be enough to totally replace the air moved and keep ATM under the car.

A vacuum might be created just by the speed of the car and the inability of the surrounding air to refill the space underneath the car above an unknown "balance" speed.

Patrick
Hi Patrick, thanks for the detailed comments.

JimL over at the Pan Skirts thread commented that he added skirts all around but left the rear open.  Above 175 mph the natural vacuum created under the car sucked the belly pan off the car down to the salt surface.  They had to tie it back up and eventually mount it rigidly to stay in place.  So that lends credence to the idea that speed alone does indeed cause a vacuum to form where pan skirts are set in place.

If that's true then mechanical suction to further evacuate the air space bounded by the skirts should increase negative pressure up to the efficiency level of the skirt sealing.  So the total volume of air being displaced by the pump second by second of car movement should equal whatever volume of air is passed through the skirts beyond the balance speed further enhanced by the amount of total negative pressure mechanically and aerodynamically created.

This design is based on a 30' L x 24" W body shell.  I'm also allowing roughly 1" clearance between the belly pan and salt surface.  The skirted area ends approximately 18' from the nose so all tolled we're looking at a static enclosed area of 3 cu.ft. or .085 cu.m.  That's 5.1 cm/mn which at 12.27 mph is a 0.41 ratio.  So I believe the more relevant number would be...600 * .041 = 246 cm/mn.  But that's assuming no negative pressure is aerodynamically occurring which JimL has shown there is above some balance speed dictated by design factors. 

I tend to believe static negative pressure will exist above a certain speed such that vacuum pump efficiency isn't tied to a volumetric speed ratio, but rather is a volumetric constant depending on the level of aerodynamic negative pressure within the suction zone.  All theory of course that will have to be physically tested with appropriate sensors. 

BTW... the big F-3X-140 Procharger draws 4500 cfm through a 6" inlet producing 60 lbs of boost at 72,000 rpm.  So here we have a 6" discharge port drawing through a roughly 9" opening.  Without gearing the impeller is turning between 8 to 10K but there's no appreciable inline back pressure to constrict cfm flow. This system would probably only work as designed if my assumptions about cfm flow as noted above are true.  Interesting stuff... Thanks, Terry.

Title: Re: Simspeed UWD LSR Design Project
Post by: kiwi belly tank on October 26, 2019, 11:36:42 AM
Your alum drive wheels currently have 0 traction.

DW
& the big vacuum cleaner will suck salt, I hear course damage. It's not going to create much negative pressure when it's pulling the surface up.
  Sid.
Hi Sid,
Yes if it pulls up the salt in chunks then its no good in this form.  So long as the skirt seal was adequate pulling the salt up wouldn't it of itself negate the creation of negative pressure given that there's always something underneath to pull against if it's solid.  Thanks... Terry
"if it's solid" should be the light-bulb in this idea, the salt is not solid.
  Sid.
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on October 26, 2019, 12:03:35 PM
A vacuum might be created just by the speed of the car and the inability of the surrounding air to refill the space underneath the car above an unknown "balance" speed.
Given a really long course, a sucker system would be perhaps superfluous. It would likely be useful to shorten the distance to speed.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on October 26, 2019, 01:33:07 PM
How about buying a used fighter plane, taking off from say Wendover, circling around until you're over the speed of sound, flying an inch or two off the salt, maybe touching here or there, making sure you activate the clocks, then looping back on a return run over the same mile and landing for the trophy presentation?

Are there any flaws in this concept?
Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on October 26, 2019, 02:06:55 PM
How about buying a used fighter plane, taking off from say Wendover, circling around until you're over the speed of sound, flying an inch or two off the salt, maybe touching here or there, making sure you activate the clocks, then looping back on a return run over the same mile and landing for the trophy presentation?

Are there any flaws in this concept?
For safety's sake, maybe you should equip the plane with really long-travel landing gear, like 20 feet. A laser-controlled aerodynamic ride height system could be used. I can't find anything in the rules prohibiting this.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on October 26, 2019, 02:29:44 PM
I've found a partner!

Too bad we're both too old to put it together on our computers.

(You got any money?)
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 26, 2019, 03:13:37 PM
How about buying a used fighter plane, taking off from say Wendover, circling around until you're over the speed of sound, flying an inch or two off the salt, maybe touching here or there, making sure you activate the clocks, then looping back on a return run over the same mile and landing for the trophy presentation?

Are there any flaws in this concept?
I'd say your attitude mainly Stan...but no one said you have to take any of this seriously.  Make of it what you will and I'll respond accordingly.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 26, 2019, 03:15:28 PM
A vacuum might be created just by the speed of the car and the inability of the surrounding air to refill the space underneath the car above an unknown "balance" speed.
Given a really long course, a sucker system would be perhaps superfluous. It would likely be useful to shorten the distance to speed.
That's the main idea I think Tortoise... Thanks, Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: Seldom Seen Slim on October 26, 2019, 03:19:24 PM
Terry said:  "...but no one said you have to take any of this seriously."

Terry, Stan is being serious - for him.  You just gotta spend a few years on the salt with him to learn his style, k?
Title: Re: Simspeed UWD LSR Design Project
Post by: TrickyDicky on October 26, 2019, 03:46:39 PM
How many planes are capable of the speed of sound at low level with the landing gear down?
Title: Re: Simspeed UWD LSR Design Project
Post by: Seldom Seen Slim on October 26, 2019, 03:59:11 PM
Well, I suppose all of 'em are if they're pointed straight down at the ground under full power,,, lol8
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 26, 2019, 05:21:17 PM
I believe that this could be taken more seriously if there was some testing taking place rather than assumptions. Having experience both with the metal spraying process and running a race car on salt, I think you really need a real world understanding of your expected results. I would say the same thing about a sucker system. A simple box and fan could be utilized on salt to see if this is even something to consider. Let alone design around. Before Jack Costella builds cutting edge stuff he builds riding models and proves the plan. It seems to work quite well in practice.
Title: Re: Simspeed UWD LSR Design Project
Post by: Stan Back on October 26, 2019, 06:10:33 PM
We must remember that Mr. Costella's vehicles do not go thru the air -- they go under it.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 27, 2019, 12:00:47 AM
Terry said:  "...but no one said you have to take any of this seriously."

Terry, Stan is being serious - for him.  You just gotta spend a few years on the salt with him to learn his style, k?
I understand Slim...thanks for the clarification.  No harm...no foul.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 27, 2019, 12:06:00 AM
I believe that this could be taken more seriously if there was some testing taking place rather than assumptions. Having experience both with the metal spraying process and running a race car on salt, I think you really need a real world understanding of your expected results. I would say the same thing about a sucker system. A simple box and fan could be utilized on salt to see if this is even something to consider. Let alone design around. Before Jack Costella builds cutting edge stuff he builds riding models and proves the plan. It seems to work quite well in practice.
Rich...for now assumptions are all I can afford.  Pre-development testing should be standard for for all new ideas, and we have more than a few included in this design. We'll see what the new year brings.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: 4-barrel Mike on October 27, 2019, 01:23:10 AM
Silly question, as I'm reading this without a lot of enthusiasm, but have you had any conversations with blue www.landracing.com/forum/index.php?action=profile;u=1554 (http://www.landracing.com/forum/index.php?action=profile;u=1554) ?

Mike
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 27, 2019, 07:09:23 AM
Silly question, as I'm reading this without a lot of enthusiasm, but have you had any conversations with blue www.landracing.com/forum/index.php?action=profile;u=1554 (http://www.landracing.com/forum/index.php?action=profile;u=1554) ?

Mike
Hi Mike,
No I haven't.  I don't believe Blue has commented on this design project.  Thanks for asking... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: salt27 on October 27, 2019, 05:46:13 PM
It has been and still is interesting watching the evolution of this design exercise.

The appearance seems to have gradually started to resemble some of the proven streamliners.

Personally I find it difficult to get too excited knowing that the chances of it becoming reality are slim.

What would Jack Dolan say, maybe "theoretical race vehicles set theoretical records".

Carry on, Don
Title: Re: Simspeed UWD LSR Design Project
Post by: Beef Stew on October 27, 2019, 06:31:16 PM
Testing is cheap and easy.

1. How to test sucker-car. Rent a wet or dry shop vacuum from your local rental yard. Attach to inexpensive cooking pot. Take into your back yard, and set over mud-puddle. Flip on shop-vac. after running open vac to see how much mud was sucked up. Cost? Should be very little.

2. Aluminum wheel with sputtered metal. Buy a small aluminum wheel and have it coated. Then put it on a grinder of some sort (rental yard sourced), then spin wheel while touching a semi-hard surface. Does it get traction? Cost? Maybe free, depending on how good a talker you are. Quit often companies can write this off as R&D?you learn something and so do they. I've got free product to test on many occasions.

The biggest problem is this. No. One. Cares. Bloodhound couldn't get money. And they had a proven track record.






Title: Re: Simspeed UWD LSR Design Project
Post by: tortoise on October 27, 2019, 09:28:25 PM
I have been following the progress of the absolute world land speed record for the past 50 years. I am dumbfounded by the insistence of Thrust 2, Thrust SSC, Bloodhound, and Aussie Invader 5R to eschew pneumatic tires and instead run their vehicles on solid metal wheels.
Since the coefficient of friction of the metal wheels on dry salt lakes, or other hard surfaces, is insufficient to provide steering control they must find semi-soft surfaces to run on. Since these metal wheels obtain steering control by, in effect, machining grooves in the race course surface, they literally destroy the course as they run and cannot return on the exact same path. Also, finding the optimal surface composition for the record course seems to be adding unnecessary complication to the search for the land speed record venues.
When we ran The Blue Flame in 1970 on pneumatic tires, the steering control was excellent as the coefficient of friction approached that of rubber on asphalt or concrete. The Goodyear tires and our wheels were tested at Goodyear at speeds up to 850 mi/h without failure. The only failure in testing occurred when the wheel mounting mandrel broke loose at speed and the tire and wheel spun around in the concrete test cell. The wheel, while not being used afterward, only had some gouges on the rim from impacting the cell walls and still looked nice as a display piece.
Three of the four pneumatic tires and wheels were replaced for minor reasons on the salt flats. When one of the two front tires leaked air (probably the O-ring seal between the wheel center and the outer flange), we replaced both at the same time. One of the rear tires was replaced after a towed braking incident (locked up tire and skidded) wore through most of the thin rubber tread. The fourth tire was used for all 24 timed runs.
Since we could design and build 850 mi/h pneumatic tires 50 years ago, it should be a simple task to design and build 1,000 mi/h tires (and wheels) with the materials and design improvements since that period of time. When I think of all the time wasted by the LSR teams trying to use metal wheels for providing the steering function I am amazed. Just my opinion.
An experienced and educated perspective on metal vs pneumatic-tired wheels on salt. If he's right in the case of thrust power vehicles, what he says is more emphatically correct about wheel-driven vehicles, don't ya think?
Title: Re: Simspeed UWD LSR Design Project
Post by: Beef Stew on October 27, 2019, 11:36:20 PM
An experienced and educated perspective on metal vs pneumatic-tired wheels on salt. If he's right in the case of thrust power vehicles, what he says is more emphatically correct about wheel-driven vehicles, don't ya think?

This is all very true. There is NO need to reinvent the wheel. Except Simspeed is locked into the idea of ultra-low frontal area. Putting pneumatic tires on the 'liner would increase frontal area?end of story.

Back in 1970, the publicity value was a win for Goodyear. Today an FIA World Record, and $2.00, won't buy you a cup of coffee, except at Mickey D's. So I sorta doubt that Goodyear would spend the amount of money needed to develop a 1,000 mph tire.
Title: Re: Simspeed UWD LSR Design Project
Post by: TD on October 28, 2019, 08:12:39 AM
Really interesting thread, keep going!

...
What would Jack Dolan say, maybe "theoretical race vehicles set theoretical records".

This reminds me of the Admiral Hyman Rickover version:  "Paper submarines work best."  :-)
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 28, 2019, 10:44:55 AM
I am frustrated by concepts advanced without any proof of concept. In the end it seems meaningless. I would like you to try a mock up of your engine drive wheel package to see just what size package you can do in the real world. This seems to be central to the whole project. I am also very concerned about your assumptions on the metal sprayed alloy wheels. Makes a nice step plate. Interested in how it will do in this application. Just my thoughts, having only recently began looking at this thread. These things may have been addressed already.
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on October 28, 2019, 11:56:38 AM
   Stan, you being frustrated advances the notion that your taking this thread seriously. I only read it for the excellent wry humor. Rich,Eddie, Bob, yourself and others have kept me in stitches. If anyone who has read this pipe dream ever won the lotto for say $200 mil.not one one them would follow this concept and build a LSR with it. In the years to come this will evolve to a car that looks like the new Arlo Langlo 4wd car with actual rubber tires.
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on October 28, 2019, 12:08:50 PM
  I actually have read this thread to see if it advanced ONE idea that could be PRACTICALLY applied to an actual race car.

  John Deere will build a 200 mph promotional tractor before the proposed solid tire design goes 200 on a land speed car at BV. 
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 28, 2019, 02:04:37 PM
An experienced and educated perspective on metal vs pneumatic-tired wheels on salt. If he's right in the case of thrust power vehicles, what he says is more emphatically correct about wheel-driven vehicles, don't ya think?

This is all very true. There is NO need to reinvent the wheel. Except Simspeed is locked into the idea of ultra-low frontal area. Putting pneumatic tires on the 'liner would increase frontal area?end of story.

Back in 1970, the publicity value was a win for Goodyear. Today an FIA World Record, and $2.00, won't buy you a cup of coffee, except at Mickey D's. So I sorta doubt that Goodyear would spend the amount of money needed to develop a 1,000 mph tire.
This is the point of my use of billet wheel/tires for this design.  No one is making pneumatic tires designed to exceed 500 mph.  Anything beyond that speed using gas filled tires is an accident waiting to happen in my opinion.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 28, 2019, 02:27:40 PM
I am frustrated by concepts advanced without any proof of concept. In the end it seems meaningless. I would like you to try a mock up of your engine drive wheel package to see just what size package you can do in the real world. This seems to be central to the whole project. I am also very concerned about your assumptions on the metal sprayed alloy wheels. Makes a nice step plate. Interested in how it will do in this application. Just my thoughts, having only recently began looking at this thread. These things may have been addressed already.
Rich...not sure what you mean about what size the engine, drive wheel package would be in the real world.  Everything you see in the drawings have been scaled to actual size give or take a millimeter or three.  Tire diameter is 26.5" and width is 4".  The differential is dimensionally accurate, as is the Quick Drive (tm) torque coupling. I pulled the dimensions off the mfg. website.  The Liquid Piston (tm) engine is designed around the mfg rotor size of 1.37L for each rotor; whereas the Mazda 13B engine uses two rotors with a combined 1.3L or 0.65L each.  The dimensional geometry for the engine components I got off the LP and Mazda websites.  The spark plugs are even dimensionally accurate. The CF 2" tubing cad drawing cross sections were downloaded from the mfg website. The rest of the car is drawn to the same scale as the components mentioned.  The driver is also dimensionally accurate standing 6'2" with a 12" long foot sole.  The frontal area is derived from a cross section of the body at the widest point and calculated by the cad program in sq. ft.  For the intended design purposes what you see in these drawings is what you'd see in the real world if the car was built to actual component scale.  Thanks... Terry
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 28, 2019, 02:31:19 PM
  I actually have read this thread to see if it advanced ONE idea that could be PRACTICALLY applied to an actual race car.

  John Deere will build a 200 mph promotional tractor before the proposed solid tire design goes 200 on a land speed car at BV.
racergeo...Please identify any idea proposed in these drawings that could not be practically applied to an actual race car given that proof of concept testing would be necessary as is the case for any new idea beyond conventional norms.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on October 28, 2019, 02:41:18 PM
   Malo has the new Goodyears and they are suited for 600. Practicality, reliability, dependability, affordability,repeat ability and especially DRIVABILITY are necessary qualities of a successful LSR effort. You need to build an actual race car and gather first hand info and then apply what you learn to this pipe dream and then someone may take it seriously. :roll:
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on October 28, 2019, 02:50:29 PM
   Terry me boy, for starters the SCTA will NEVER allow your tires to be tested on the salt race course. (maybe the bend in the road) :laugh:  The indigenous people of AU. will not allow their sacred salt to be ground. That leaves you with in South America with Mike Cook's fluid English.
Title: Re: Simspeed UWD LSR Design Project
Post by: Simspeed on October 28, 2019, 04:05:40 PM
   Malo has the new Goodyears and they are suited for 600. Practicality, reliability, dependability, affordability,repeat ability and especially DRIVABILITY are necessary qualities of a successful LSR effort. You need to build an actual race car and gather first hand info and then apply what you learn to this pipe dream and then someone may take it seriously. :roll:
racergeo...this design is conceptual at it's core.  Whether you or anyone else takes it seriously is not my concern.  I posed these ideas in order to get feedback so that I might learn things about the sport, the cars that race successfully, and the experienced people who build and drive them.  I've received quite a lot both pro and con while offering up ideas that by their very nature do not represent the status quo.  I agree the factors that make a successful LSR effort are much as you stated. However, you failed to mention the importance of creativity in both design and execution of ideas that set one great car, team, effort apart from another. 

Where does that extra ounce of speed come from that breaks old records and sets the bar a little bit higher for the next attempt? How do we know what's practical, reliable, dependable, affordable, repeatable, and driveable unless we think beyond the status quo and look for new or different ways to move the needle higher?  Different does not necessarily mean wrong.  It may prove to not work but how will we know unless we conceive new methods, materials and processes to be tried and judged in attempts to find a better path forward? 

There's not one single idea I've proposed that can not be reasonably adapted for testing to learn if it might meet the criteria you defined for a successful LSR effort.  Until and unless an idea proves to be faulty, naysayer misgivings you and others have voiced are no more valid or meaningful than my conceptual notions that they may actually work as intended.  I'm more than willing for any or all of my ideas to be proven wrong.  That's because I know chasing LSR records successfully will require forward thinking beyond what has worked successfully in the past.  I do appreciate everyone's input on whatever level you care to contribute.  Just be certain your bah-humbug attitudes don't define how you want the world see you...because they will if you're not careful.  Thanks... Terry.
Title: Re: Simspeed UWD LSR Design Project
Post by: RichFox on October 28, 2019, 04:19:31 PM
As I said, I am a late comer to this thread. So I may have missed something. However I have seen both the power pack in the wheel electric proposal and the torque converter drive. Drawings are OK. But in my experience real world concerns often cause things to grow. With the new design it's not as much of a issue. But I still think that is why people build models and mock ups. To find out what runs into what that you thought was OK. Maybe computers have made things better for designing a complex device. But I still think Real World testing is the last word. Also. My experience with metal spray is 40 years ago. So I am way out of date. But from what little I can see, it looks like a Metco wire process spraying aluminum on a surface. I've done that. You can get around 50 grit sand paper surface. But it's soft and has poor shear strength.  Have you as much as contacted the company you are counting on, for their thoughts? Maybe a small sample of the product you could test? I know that there is no expectation of any metal ever being cut on this project. But even for what it is, some solid information is necessary or it's just a wast of time.  IMHO
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on October 28, 2019, 05:27:49 PM
  When you have driven on wet salt at 250-300-400??? mph, made a split second  correction to prevent what would have been a crash,guided a car to a safe stop that's parachutes had failed,made tuning decisions resulting in several mph more speed resulting in a record, all while watching a yaw (ha) string then I'll be the first to say "you can do it"". Till then, what Rich just said :-D
Title: Re: Simspeed UWD LSR Design Project
Post by: racergeo on November 03, 2019, 10:16:58 PM
  I'd like to be defined as the guy that helped you decide whether your ideas have any merit. There is a shifter kart with a 450 cc Honda engine for sale on E bay. An actual race shifter kart has 125cc. Buy it. build an aluminum ring 4 " wide (flat for contact patch) that is slightly smaller I.D. then the tire with say 10lbs air. Pump the tire up to 40 lbs and your ready for snow. Wait till your rode gets well compacted and give it a go. If it works as well as studded tires and hopefully even better then you have cause to go to World of Speed. In the past they let go karts run on the mile course. They always spun out numerous times and held things up, so they discontinued allowing them.  If you contact them and tell them you are testing for a 600 mph effort they probably will let you run on the outer edges of the track. If your traction ring is fairly thin then if it does dig into the course the rubber tire that has little traction will act as a limiter of damage.Once it digs down to the tire, it being 11 inch wide will prevent it from digging further.  If this idea (solid tires) that many have poopooed has any merit, then a shifter kart is the ultimate I told ya so vehicle. I have owned two 125cc shifter karts and they were brutal. This 450cc kart properly geared should go well into the 150 mph range. In my mind you are defined by the following remark,"but frankly I don't see rubber tires advancing the unlimited records much beyond todays marks" PROVE IT :evil: :evil: :-D