I need a faster gear change for the 1-2 shift. Currently its scanning a 0.3s timing pull. I have the WOT shift at 6250RPM and 38MPH and it completes the shift at 6500-6600RPM. If I raise the RPM any higher it bounces the limiter. How can I shift faster so that I can raise the RPM to 6400RPM?

I have a rebuilt shift-kitted tranny. I have 0.16-0.22 shift times in the shift time vs torqur tables. No matter what I changes there I cant get a faster shift.

Is there a tranny mod, TQ reduction table or force pressure table I can mod. top achieve a shift duration fo 0.15 seconds for the 1-2 WOT shift? Or am I being too wishful?

 

Do you have a shift kit in it? A TransGo shift kit, for example, gives you the ability to adjust the firmness of the 1-2 shift by adding or subtracting washers from the 1-2 acummulator housing. The difference between a shiftkit and programming is that the kit will move more fluid into the servo at a lower line pressure than the stock calibration will. It also greatly improves the sloppy stock 2-3 shift.

When you set up the firmness for the 1-2, start small. It's better not to go overboard with the 1-2 shift or you will end up with jolting bangs at low throttle too. The 4L60-E dos not have internal parts strong enough to handle excessively fast firm shifts, so firm it up to what you need and no more.