I was at the strip on the weekend watching the races. I was wondering what is the technique with a Auto to get the best time. Thinking I might give it a try If I knew how it's done. I guess you launch in 4hi, with some boost built. When do you take it out of 4hi and what gear selector ( 3rd or OD ) does a fella run?

 

I run mine all the way down the track and take it out of 4hi when I let off the gas.

If your auto is stock be careful not to boost it too high or you may take a shaft out. 5psi or less.

CRIS

 

from what I've seen and heard, these are the steps for absolute BEST 1/4 times:

Step:

1. Turn OD off, so turn TOW/HAUL mode light on
2. Put into 4HI
3. Brake torque right at or before redline
4. wait for GREEN and release brake and punch it

 

Like I said before don't go over 5psi wiht a stock tranny, If I was to go up to just under redline I'd have over 40lbs of boost and I wouldn't have a rearend or a tranny left in my truck. So don't go over 5psi.

CRIS

 

what if you have a built tranny? What psi can you launch at?

I was telling my trans guy about these boosted launches and he said that it's fine (billet) but, you are building an incredible amount of heat in that converter, so he recommended to get it to boost and launch as soon as possible.

 

When I race, I run all the way in 4hi and shift out before I start making the turn off the track. I run in nomal drive mode, OD is another gear to gain speed with. I have a TC lockup button that I lock the TC with after it shifts to 2nd and keep it locked until I let off the throttle at the end of the quarter. At the line I shift to 4hi then ease forward until the prestage light is lit. Then power brake and build boost up slowly until I am at 15psi or so. Then bump brake to move forward to light full staged light. Try to keep boost at 15psi and maybe creep a little higher until tree hits last yellow light. Then throttle on the floor until the end of the quarter. I do have a full billet trans built to race with. The only thing I need for drive train is billet flexplate. Then I will have a switch to force OD shift around 70mph. Afraid to do that with stock flexplate.

 

I launch at 20psi, in 4wd, pushing it out in 2nd gear (takes a 1/10 off the ET)

Lock the TC in 1st gear right after it launches, and keep it in the normal drive position.

Then hold on and keep it straight.

 

I'm a little confused on the boost building before launch. When I do a brake stand I have to build about 10 lbs before I brake the tires loose, and when I pull I know that I build around 10 lbs before launching. 5 psi just doesn't seem like a lot of power. Like I say I've done more than a few brake stands and hold the brake until 10 psi or higher. How does 5 psi break an input? I just don't get how it could... could somebody please enlighten me?