Quote Originally Posted by JD1964 View Post
Thanks for that input NomakeWan,

The datalog shows the PCM commanding the shift according to the tables in the bin at 5450rpm. However, the shift is not completed until 6100. There is no slipping whatsoever in the climb through the powerband and when the shift happens, its solid with no apparent slippage or slush. It's obviously being delayed within the transmission but when it does happen, it feels healthy. So, I don't think I have any clutch slippage issues.

The story on this donor car (94 Z28) is the mother let the kid drive it and he put it in a ditch causing moderate damage to the right front corner. Thats what took the car off the road. The car sat for several years after that. When I bought the car they claimed the transmission had been rebuilt a few months before the kid wrecked it. When I pulled the engine / trans from the car I found initials and date written on the bellhousing with sharpie marker. The data coincides with the time the trans was claimed to be rebuilt. She said she knew the mechanic and he was familiar with the weakness of these transmissions and he had done stuff to improve it. She did not know exactly what so neither do I. Not to ramble but this may support my position that the transmission should be healthy internally.

I did some research and found this thread which further helps me understand things. Look at line 5 about shift timing. I think Ill try adjusting the the max MPH lower to see if that gets me where I want.

http://www.gearhead-efi.com/Fuel-Inj...vations-(8051)

Also, further down in that post look at line 3 in the tuning suggestions. I compared those suggestions with my bin and I think I found another potential issue with my bin. I posted the table below. The tuner (who I'm sorry I paid) has errors there too I think. In the 2-3 shift timing its set to 6.38 seconds. Shouldnt that be .638 sec instaed?

shift-time.png
Just because someone claimed to build it doesn't mean it was built right. I'm not saying it was necessarily built wrong, but there are a lot of folks who claim to build 4L60Es that end up being trash. It's not a complicated transmission, but you have to actually care about your work and actually know what you're doing or it's very easy to overlook a component (or cheap out) and end up with a junk transmission not too long afterwards. Garbage in, garbage out.

Your table looks bone stock with zero modifications. I see nothing wrong with it. It doesn't appear the tuner touched it at all.

Quote Originally Posted by LeMarky Dissod View Post
NEVER used a shift time higher than .750.
6.375 is the shift time for T56 .bins.
Nope. I have a stock '94 Corvette with a 4L60E, and this is my table:
4l60estock.jpg

Not saying you can't do better by messing with those values, but claiming they're wrong is incorrect. They're factory GM values.