Landracing Forum
Tech Information => Technical Discussion => Topic started by: robfrey on October 22, 2009, 01:16:13 PM
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I'm thinking about putting a pushbar on my twin turboed LeMans for next year's Speedweek.
We were only able to get our Lakester up to 60mph before the first set of cones with my wife's Denali which by the way, I'm still cleaning. LOL
If I could give him a 120mph push, I'm sure we could put 40 or 50 mph on our 2-1/4 speed. It was only 247.
I would probably have to add some ballast to the rear to get the traction but everything else should be stout enough to do the job
(http://i436.photobucket.com/albums/qq89/robfreyvogel/63%20Pontiac/P1090170.jpg)
(http://i436.photobucket.com/albums/qq89/robfreyvogel/63%20Pontiac/P1090176.jpg)
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Is there any legal limit on how fast we can push?
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nope.... they don't like you to push more than a mile though
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That lakester should be able to get up to speed faster by itself, what is your low FDR? we run a PG with a 2.14 gear set and have run 269 1/4 speeds and we are of the truck in 4-5 seconds -- we put it in low range 4x4 and are off the truck at about 30 mph
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Most of the drivers I know can't wait to get away from the stinkin push truck - You really want to have someone pushing you 120 MPH??? We gave up on high gear only decades ago. If you are not running good enough to get away from the truck way before the first cone something in your setup needs changing - either the engine tune up or drive train combination - Pat :-D
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RIGHT ON..........Pat.
If the car isn't faster than the push truck, somethings way wrong.
FREUD
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Ask Lee Kennedy why the push truck was waiting for him at the far end. Lee= Putt-Putt. It's a long stroy folks lol
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Aw come on Glen, share the story! :-)
Lynda
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We have a much slower vehicle, but I was always criticized for pulling away after about 15 feet. I figured I could accelerate faster than my 3/4-ton pickup in 2nd gear. We compromised in a 1-2-3 count and hit the brakes, and it's worked for us. I don't have to worry about being run over.
Stan
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Well, we have a certain amount of ice water on board for cooling and intercooling. I was just figuring that any accelerating that we didn't have to do would leave more ice for top end (when we need it most) but this is why I ask you guys as I am very green to this.
We have a 2.48 : 1 first gear. I like to be going at least 60 and that's about 3000rpm with the 1.84 rear gears and 28.4 dia. tires. i know they say 30 tall but that not what they measure. Especially at that speed.
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We weight about 1M# less than you :
but if you had a very weak spring in you bypass or blow off you should be able to acclerate from 1000 to 1200 with a turbo cam pretty good then when you shift you should be able to start "dialing up your boost---I plan to try to increase my boost torque so that my TE is the same as my lowest gear TE was that I could hook up---as your mechanical mulitiplier decrease whith each gear shift one should try to increase the eng torque to off set---One should strive to KEEP the TE the same!!!!!!!--after each gear change!!!!!!!
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OK Sparky, I'll bite what is TE??
Rex
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I'm probable a car that benefits from a fast push off as I have a 2 speed and a 1.76 low. When I asked Lee Kennedy about a supercharged (PSI) push truck :wink:He stated that his rule of thumb is the push truck shouldn't be faster then the car It's pushing! LOL
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Rob... everybodys forgeting about Carl Heap and the Phoenix ''unlimited diesel truck'' 285mph. weighed about 14,000 lbs got pushed by a diesel tractor that would go 118mph at the drags [what a sight that was] and Rick Vesco has a fast jeep thats pushed a fast streamliner.Don Vesco 475mph I believe.
JL222
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Rex
TE =Eng TQ X TR X RA
TQ= eng tourque
TR = trans ratio
RA = Rear axel ratio
another way of stating it is FDR X TQ= TE
FDR = Tr X Ra
every trans gear has a FDR
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222 - Nobody will ever forget Carl Heap or the Vescos - ever. If you really believe your crews skill sets match those two teams then have at it. I can just hear Glen making the play by play call. Pat :-D :-D
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Rob... everybodys forgeting about Carl Heap and the Phoenix ''unlimited diesel truck'' 285mph. weighed about 14,000 lbs got pushed by a diesel tractor that would go 118mph at the drags [what a sight that was] and Rick Vesco has a fast jeep thats pushed a fast streamliner.Don Vesco 475mph I believe.
JL222
Rick and Don used that jeep for a couple meets, but on the record run they pushed off with an ATV.
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We weight about 1M# less than you :
but if you had a very weak spring in you bypass or blow off you should be able to acclerate from 1000 to 1200 with a turbo cam pretty good then when you shift you should be able to start "dialing up your boost---I plan to try to increase my boost torque so that my TE is the same as my lowest gear TE was that I could hook up---as your mechanical mulitiplier decrease whith each gear shift one should try to increase the eng torque to off set---One should strive to KEEP the TE the same!!!!!!!--after each gear change!!!!!!!
We do have a very weak spring in our wastegates which will allow us to accelerate with very little boost but Icewater in the intercooler is not nearly an issue as icewater in the heat exchanger for the radiator. Any power going into accelerating the car heats the coolant water and in retrospect I should have built the car another 6" or 12" longer to fit a bigger tank. But then I would have needed a longer trailer which was not in the budget this year. LOL.
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What is the temp of the water coming out ot the intercooler.I am building a new heat exchanger for my two pass radiator and we will be running the cooling water from the intercooler thought the first pass and saving our cool water for the second pass.
Up untill now we have been running a 2 pass coolant box that encloses a 2 pass radiator this way we can maximise our heat transfer, by coolest colant to coolest radiator.
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Rex
TE i=Eng TQ X TR X RA
TQ= eng tourque
TR = trans ratio
RA = Rear axel ratio
another way of stating it is FDR X TQ= TE
FDR = Tr X Ra
every trans gear has a FDR
Man, no one said I'd have to pay attention in those math classes....................... they were SO long ago
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Sparky,
We have not been monitoring the water temp back to the icewater tank so I can't answer that yet.
The drag racers have been circulating the used water from the intercooler though the engine and back into the tank thus eliminating the radiator.
I don't know if I like that idea for a five mile run.
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Here is an interesting story. If it can be backed up - fine! If not - "Never let the facts get in the way of a good story."
http://flatheadV8.org/RS%20Tales/kennedy.htm
will
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Say we do decide to do this and give a mighty push with the 63 LeMans. How will the drag radials hookup on the LeMans for the pushoff? If you think that I will just spin all the way to the release, it probably will not be worth it.