I ran my car at the track last night and while spraying n20, the 2-3 shift was taking very long. On motor its crisp, so i assume there is a clutch slipping due to the extra power.
Any recommendations other than not spraying through shifts? i can always resort to that.
Increase pressure etc?
I have a transgo stage 2 shiftkit in it.

 

While possible its slipping. I think its unlikly if the normal WOT shifts are solid. Bear in mind that you must allow more "RPM" between commanded and actual shift RPM as power increases. The real time it takes to complete a shift in .sec is a constant, But the rate of RPM increase becomes faster as power increases.

 

Good point, ill try adjust shift points and see if that works.
Thanks!

 

Did you do the TG-2 kit?

 

The TransGo kit takes care of a major weakness in the 4L80E. However in doing so it can slow the shift a bit.
When I build them I don't use the kit, I do the mods internally but there is an additonal mod that needs to be done to help the 2-3 shift.

 

I am starting to see a trend here... my -3 kit with vacuum modulator has had a similar problem since the first test drive. Since then I drilled out the three holes in the separator plate to the max (.140") as described in the transgo instructions, and shimmed up the smaller band actuator as tight as I dare. The 1-2 shift is very firm , the 3-4 shift very very firm and almost instant, but the 2-3 shift is still late, and slower than the others.

What now??? The transmission holds full throttle with the converter locked, so I don't believe it is a clutch pack or band problem.

I am really ready to buy a good converter, but not until I can get the transmission to shift 2-3 better.

 

I modify the TransGo kit to reduce this shift lag. It's the biggest complaint with the kit.
You also need to install stiffer shift valve springs to prevent another issue that occasionally pops up.

 

when i first built my 4l80e, i used the hd-3 man shift kit, same 2-3 slow shift
using the man shift on a street car got old quick, 1 more shift than a 400, lol
i swapped out the v/b and used the auto mod, compushift controller, and the transgo hd-2
much better, and the more i drive it, the better it gets-1-2 shift smokes the tires, 2-3 gets a chirp
when i ran it a couple weeks ago, 12 lbs boost, soon as i shifted it, it hit, my guess max line pressure-if i build another, i'll prob bug Jakeshoe about int. mods for the 2-3, but right now its everything i want in a trans
i think having a lose converter compounds the problem a little, the need for mods to fill the fluid void, although i may be way off