4L60E adjustment questions

Can someone please explain the effects of adjusting the values in the following tables?

Shift Pressure vs Temp - I assume that this table has to do with shift firmness, but does a higher number make a firmer shift or a lower number?

Line Pressure vs %TPS 0-64 and over 64 MPH - What effect does increasing the line pressure have. I'm not worried about increasing the max line pressure, but rather just wondering what the effect of increasing the line pressure from say 31 to 41 PSI would be.

Pressure Offsets for normal and performance mode- What effect does increasing or decreasing the offset have on the vehicle?

Target shift time - I noticed that the 1-2 shift time is so much shorter than the 2-3 shift time in the table, why is this? And what would be the effect if you adjust the 2-3 to be closer to or match the 1-2 shift time?

I got one answer via the LT1 Edit mailing list, but I'd like to get more opinions on it.

line pressure i know is shift firmness the higher the pressure the firmer the shift. From what read its best to leave the stock values as it can cause damage and really doesnt improve performance in the 1/4 mile or anything.

the LOWER the number in the shift pressure vs TPS table the HIGHER the shift pressure will be.

Example at 30% tps the stock table is 600, if you LOWER this number to 500 the shift pressure will be HIGHER and you will get a firmer shift.


as far as the REST of the auto tranny settings go DONT TOUCH THEM unless you want to shorten the life of your transmission greatly. Not to mention even if you knew what you were doing tranny fluid cooler would be needed to cope with the extra temp that increasing line pressure and shift speed would cause.