Finished the motor install and we've been tracking down a vibration. After reinstalling the trans with the stock converter (Ed Wright programming for VIG 2800 still installed), the car won't make the 2-3 shift unless you back off the throttle a bit. Would the programming cause this? It's also got a recently installed Transgo kit, and hasn't been pushed much since we're still breaking in the new motor. I was hoping the stock trans was going to last for at least the breakin and some dyno runs. How much power can a stock 4L60 typically handle? Fluid level was a bit low after the converter swap, but we've topped it off and it seems to be fine now. Any ideas on what to check?

Alternately, who's making the best tranny these days? I want something capable of handling in excess of 600rwhp.

 

Depending on how much horsepower you have, you will need to modify the Trans-Go Performance Shift kit (larger feed holes) & add the vacuum modulator. This will give you more oil volume to the 3-4 clutch pack & the modulator will add about 40-50 lbs. of main line pressure at WOT in the "D" position. I do these modifications on all of my Performance setups. If I can be of help, let me know?

 

did the fluid fix the shift? if not the yes the program mar be off by a couple mph.

not to sound like a jerk so no offence to pro built, but the best guy to build a trans is john gobel. 600 hp shouldnt be much of a problem. he has numerouse 4l60's in the 9 sec 1/4's. you can pm me if you want his number, i have close to 7,000 miles on mine and the trans hasnt falterd once.