Hello my name is Bernard Rivers,
I have a 78' Trans am with a 496bbc with powerglide. I was previously using footbraking and I got a 1.53 60' foot leaving at 2200 rpm. Now I have transbrake and am leaving at 4200rpm and I received a 1.53 60' foot (believe it or not). I change the chip in my MSD box to a 4000 and I received a 1.50 60' foot.
 
When I bought the motor the guy we bought it from said his best 60 foot was 1.38 but it averaged low 1.40 - 143 60' foot leaving at 3500 rpm footbraking. (He didn't use tranbrake)
 
What could be the problem? I thought leaving at a higher rpm means better 60 foot times.
 
My converter is build for the engine and my car is 40lbs lighter than his was with me in it.
 
Do you think I need to leave at a lower rpm?
 
Thanx alot. All info would be appreciated
Bernie

Bernard Rivers

Bernard. Yes, experimenting with your particular car combination is what it takes to learn what it likes. When we set up a transmission and torque converter combination for a customer’s car, first we set the stall point somewhere around the engine’s peak torque. Then, just as a starting point, set the two point about 500 rpm below stall.

That way the engine gets a run at the stall and revs up through the stall. You should experiment by raising and lowering the two step to see what the ET slip looks like. There are many variables: tune-up, tire pressure, front tire size, etc that can help or hurt 60’ times and reaction times.

Mike

Mike’s Transmission
Lancaster CA
(661) 723-0081
www.mikestransmission.com