launch technique

[chad]

Currently I'm running a stock stall converter in my chevelle when I launch it at the track I foot brake it to 1500RPM. This is the highest it will go before spinning the tires. I talked to a Friend of mine with a 3000rpm stall and he said that if you have a stall converter that you no longer need to or should use the foot brake technique when launching the car. Is he right?

[chevellianrob]

I don't know that there is a wrong or right answer to your question.

All torque converters are stall converters, stock converters generally stall around 1500 rpm.

Some cars will launch better with the suspension loaded, others will launch better by hitting the tires a little harder.

Try both techniques to see what works best for your car.

[chevguy65]

As chevellianrob stated try both, load and no load.

I personally run a 3400 rpm stall that flashes at 4000.
I put no load but cannot say my 60' has been spectacular.

One reason is I was running a bad carb that had been damaged and loaded up bad. It would try to die doing my burnout.

I also have drum brakes, not to good shape and if I tried to load the suspension I would roll through the beams.
New disc's are going on this winter.

I think what your friend is trying to say is that with a higher stall the engine will jump up to flash as soon as you mash the pedal, therefore not needing to preload.

I personally would like to preload my car just a bit and see what happens.

I will say a higher stall in your car will make a huge difference.

[bracketchev1221]

Basically what has already been said is true. Most street cars will benefit from leaving just off idle. It's not a matter of loading the converter. It's a matter of loading the suspension. The only thing the car has to absorb the shock of leaving is the suspension. If you powerbrake the car, (most brakes will be overpowered before the converter stall is reached) this will load the suspension and the only thing left to take the hit is the tires. Without slicks this usually ends up with tire spin. A car that may benefit from bringing the rpm up is a car with a real big cam and loose converter (4500 and up.) In these cases the car has no torque at 2000 rpm so to bring it to 2500 will get it through the dead spot quicker. Hope this helps.

[SpiderDan]

Great info Chad, I hope to see you and your car on opening day at Maple Grove. ;D

[chevguy65]

Sorry, I missed that, I meant to say load or preload is on the suspension.

Thanks for the clairification bracketchev1221