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Author Topic: Simspeed UWD LSR Design Project  (Read 19070 times)

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Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #210 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.

Offline superleggera

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Re: Simspeed UWD LSR Design Project
« Reply #211 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).
« Last Edit: September 21, 2019, 01:21:58 AM by superleggera »
- me: Mark - home: Dry Heat, AZ USA - build underway: J-BFS Streamliner

Offline Doc B.

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Re: Simspeed UWD LSR Design Project
« Reply #212 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

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #213 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

Offline Beef Stew

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Re: Simspeed UWD LSR Design Project
« Reply #214 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.


Former record holder at RIR ½ mile drags, El Mirage and Bonneville.

Beef Stew doesn't have his head where the sun-don't-shine. His head is in SoCal where the unusual is an everyday happening.

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #215 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




Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #216 on: September 27, 2019, 01:37:33 AM »
Attachments

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #217 on: September 27, 2019, 01:40:42 AM »
Again these are out of order because of the file size limitations here on the forum.

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #218 on: September 27, 2019, 01:41:55 AM »
More...

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #219 on: September 27, 2019, 01:42:26 AM »
more...

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #220 on: September 27, 2019, 01:42:59 AM »
Again...

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #221 on: September 27, 2019, 01:44:21 AM »
Resizing...

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #222 on: September 27, 2019, 01:45:02 AM »
Almost there...

Offline Simspeed

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Re: Simspeed UWD LSR Design Project
« Reply #223 on: September 27, 2019, 01:48:46 AM »
Last one...

Offline thefrenchowl

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Re: Simspeed UWD LSR Design Project
« Reply #224 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.



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:



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...



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!!!):





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.



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

« Last Edit: September 27, 2019, 04:56:10 AM by thefrenchowl »
Flat Head Forever

...What exactly are we trying to do here?...