Built 4L60E 2-3 Shift Issues

[zracer323]

To give you a little background, after installing a built 4L60E, I cannot get the thing to respond to any changes in the tune dealing with the 2-3 shift. I suspect it is a pressure issue at WOT because the cars shifts perfectly at partial throttle. It will bang the rev limiter on the track before shifting, but on the street it will shift around 6000 rpms every time no matter when the shift is being commanded.

I have attached my tune and log file from a run I made on the street tonight. Note I am commanded the 2-3 shift to happen at 5200 rpms and 58 mph. I logged Force Motor (PCS) Line Pressure on this run. Does anybody know what these values should be? Should they match the Max Pressure on the Auto Shift Properties tab in the tune?

Any help is greatly appreciated.

[planethax]

Hmmm Maybe try tweaking the WOT Shift vs Speed

[zracer323]

Hmmm Maybe try tweaking the WOT Shift vs Speed

I have used many different values in those tables with the same results. I had even zeroed it out to force it to shift by rpm but it made no difference.

[flame]

Your 3-2 downshift mph is higher than the upshift in the 100% column. You can also try adding some pressure in the 2-3 shift. By the log you are in the 260-300 ft/lb range. Also what size tire you running?

[zracer323]

Your 3-2 downshift mph is higher than the upshift in the 100% column. You can also try adding some pressure in the 2-3 shift. By the log you are in the 260-300 ft/lb range. Also what size tire you running?

Thanks for the input. I actually noticed that yesterday when I was doing some research. I added some pressure across the board in the shift pressure table. Once we get some dry roads aroumd here I'll give it another try.

[almarconi]

Could you post a stock file for your car?

Don't know what stall are you running but the part throttle shift tables don't look quite right. Can you post the stall?

Do you have a shift kit installed? I would return the max pressure to stock value and let the shift kit take care of it.

I don't understand what you are doing with the TCC apply release speeds. The max value should be 256 not 234. The release should be one less than the apply ie (256/255). There is really no need to lock in 3rd either, you could set these to 256/255. You can adjust the 4th apply/release to suite your driving habits.

I think I would set the WOT shifts at 6400-6300 for all shifts.

Normal Table
1>2 6400
2>3 6300
3>4 6300

[zracer323]

Turns out the shift pressure table needed modified. Everything is working fine now.