Launching Techniques for TDI's (Drag Racing)

[COMP461]

I am not using a throttle plate ,

what you are describing with RPM limiting during the run based on RPMs rates of climb , is something that NHRA outlawed in the Pro Ranks a few years back it was incredible , they would draw a rpm curve , and if the engine spun the tire , or got outside that perimeter it would chop timing on a gas motor.

On a diesel it would be even easer just adjusting the throttle voltage, The device I use is a prototype device made by RPM Performance , the people that make one of the best Data logger available .


The traction control is available from Davis Technology’s thru Nitrous Express, but the price is out of this world at something like $4000 . it’s a must have on a 10.5 tire .
I have talked to Randy at RPM and he can make the system where it has two different rpm limits , one for the starting line , and there after turn off the system , or change the limet on subsequent activations when the clutch is pushed in.

 

[Sooch]

Ok, no throttle plate, got it. I wasn't asking for the level of complexity of the banned system. I tuned a simple two step on my '00 Mustang GT (since sold) with the stock computer using the TwEECer. I set a limit of 4500RPM until I was moving over 2MPH and then it switched to 6500RPM. I ran slicks all the time, but if I was on street tires I could have easily coded the first limit to something that wouldn't blow off the tires, at least until I shifted into second or third.

A simple two-step is all I think I would need at the track with this TDI. I have to think that one of our tuners here could do this in the stock ECU.

 

[COMP461]

what your describing on the Mustang is a very simply version of the banned system
I am not sure a tune could give you the instant adjustability

 

[hatemi]

I have thought about using the ECU built in 1200rpm limiter with bake pressed in but modified with different RPM limit. The thing is that it has a delay and it could possibly be modified to what suits it best. Need to do some testing on it at some time. It might help getting the launches consistent. That system could even be within the rules since it doesn't monitor the wheel speed that the proper systems do.

 

[COMP461]

the secret to drag racing is to keep everything consistent, and repeatable, and to keep extensive records

 

[jimmybling31]

i would be happy with a 2.0 60 ft

i could get 1.7's in my camaro z28, but i'm building it now and im not expecting to have the same times.... im expecting closer to 1.6 with a much higher trap speed..... much higher

 

[Gary Miyakawa]

Last time at the strip, with an open diff, I was 2.33x for all 4 runs. Finished up in the 15.5 range... New Beetle, full interior... Though, I did have nitrous (just to clean up the run).. If you look around here, you'll find a video of the runs.. (TDI Fest 2002 or so.... Grand Rapids Mich.)..

Biggest thing I needed was a Quafe... but wasn't willing to spend the $$ for it..

Have fun !

 

[orion2.0]

From what I have heard... the auto trans tdi's are disadvantaged because they are a weak transmission...and the manual trans tdi's are at a disadvantage because you cant load the engine and build boost before you launch (like the diesel truck guys do by applying both the brake and throttle).

Out of curiosity, has anyone tried using the e-brake and feathering the clutch on a manual tdi to load the engine and build boost.... then releasing the e-brake to launch? Possibly in 2nd gear?

Obviously, that would be hard as hell on the clutch. Possibly too many things to control at one time.

 

[COMP461]

working on the possibility of a auto now , but its astreinght issue.
You would never want to launch in second gear , the reduction in gear ratio, would kill the ability to get off the line and move the mass. And if the tire ever gets lose , it would spin so fast , it would never catch up
Not only did I think first gear is not enough , I went to a 4.25 gear.
And the ebrake thing is a problem , because the sport of Drag racing requires fractions of a second reaction times , or you going to lose to a seguway.
The best bet is use a tune that lets you build boost in free rev and rev the engine up to a point that when you launch the clutch catches the tire together.

 

[Sooch]

The best bet is use a tune that lets you build boost in free rev and rev the engine up to a point that when you launch the clutch catches the tire together.

Yeah, like I said, a two-step. Any tuners out there with a way to limit RPM based on the clutch switch and speed? Jeff, Charlie, VKMikel...one of you likely know how to do this.