4L60E Corvette / EPC hack via hpt - need opinion

[sv_insight]

Hi guys, I need your opinion here, it seems that I might be finally solved my long standing problem here. My tranny has been rebuilt for 5th consecutive time (7000$+). Trust me, it is perfect, with all aftermarket components, but every time the same story - lost of 3rd of 3rd+4th gear.
Obviously, the problem was not mechanical. I tried to observe the behavior of the tranny with GM Tech2 and I was amazed to see that the calculated engine torque was really not corresponding to the real one, I mean, I know the difference between 100 Nm and 300 Nm (I am from Eastern Europe). So any engine tunning was not an option since here no one can make such, and the car drives really well with CAI and COMP Cam.

I decided to check the the Positive Force Motor Current. I know that 0 amps means max line pressure available from the EPC and following the logic decided to start lowering the values from an earlier point of torque as you can see in the attached image - to get more line pressure at lower calculated torque values. My shifts got firmer but also 3rd is not slipping at all.

What do you think is this going to work out for me, or maybe I also have to edit the Negative table? I assume that Positive in this case means that this is table which controls the decreasement of the EPC current to get positive change over the line pressure.

Maybe I am totally wrong, but please tell me your opinion, the honest one. Respect.

ForceMotor.jpg

[abc]

Without playing the guessing game with you, If I assume the vehicle is mostly stock and just adding a cam will not over power a stock rebuild transmission in a C5, you have some other issue going on with the transmission other than a tune issue.

Adding more line psi via the FMC table will help with clutch engagement and the typical practice is to adjust both the pos. and neg. tables the same, but I admit I don't know why as to what the difference is between the two tables.

Stock C5 tunes were not destroying 4l60e transmissions, so I think it would be safe to say you are having a mechanical issue with yours. Yes, you can make the trans. tune better but, it is a compromise between, longevity, drivability, comfort, and performance. Know this, you typically cant have high performance combined with comfort, depending what your definition of high performance and comfort is.

If you post up the .hpt file and a current log of moderate accel and WOT accel through third gear we can take a look assuming your logging TCC slip, rpm, speed, current gear, FMC desired, and actual to start with.