Shifting Gear in a Torque Converter Car

We have been racing a torque converter blown pro mod with a Lenco using air gear shift.

Originally we did not have restrictors on the air shift which would unsettle the car on the gear shift.

We added restrictors 0.027" with 200psi bottled air to the air shift a year ago which helped the problem a fair bit, but we still have an issue with the gear shift unsettling the car.

We are now trying to take timing out on the gear shift using the MSD and taking timing out at the shift rpm to try and reduce the power whilst shifting to try and ensure the car does not get unsettled.

Any recommendations as to how much timing to take out?

 

If its a CS1 could it be that the 200 psi is locking the pack too quickly and that is why the restrictors helped?

 

Yes we are running a CS1 and it was locking too quickly which is why the restrictors helped.

 

shift timing

We've tried jets and ended up with a digiset and airswitch wired per Mike C. We dumped 6 degrees for .2 and still had a big spike on the graph shifting a 2 speed screw promod from 1.41 to 1-1 with 4.86 rear.
I tried 8 degrees for .3 and it cut the size of the spike in half.

 

It isn't always the number of degrees taken out of the base, it's the rate of gain that follows. Most guys try to shove it all back in far too quickly, effectively making the motor more pissed off than it ever was before you removed timing.

Brandon Booher
NHRA TAD #323
Torque MGMT. - Owner

 

shift

thats a good point. I'll try it.