Simspeed UWD LSR Design Project

[Simspeed]

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.

[Simspeed]

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

[kiwi belly tank]

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.

[Simspeed]

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

[kiwi belly tank]

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.

[Rex Schimmer]

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

[Simspeed]

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

[Simspeed]

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

[Simspeed]

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

[thefrenchowl]

Hi Terry,
From a complete novice AND vintage bike rider (  )!!!

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!!!



Patrick

[Simspeed]

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.

[Simspeed]

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.

[manta22]

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

[Simspeed]

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

[Simspeed]

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