4L80E, Tuning Help

[Buick Motorsports]

Steve, it is the Gen 2 (red case). any additional info you can give us on calibration is so greatly appreciated. BTW, when I was talking to him last night, the Shrifter came up. He may be a client in the future, his eyebrows went high up when I said paddle shifting.

Thanks again.

Shift timing is based on TPS position and VSS reading unless the TPS is at 100% WOT. Then shift time is based on RPM. First rule of any TCU calibration is to make sure that the TPS is fully calibrated. The calibration process varies slightly depending on whether the TCU is Gen 1 or Gen 2 (PCS). Please clarify if the TCU has a silver cast aluminum case (gen 1) or a red case (gen 2).
As for VSS, it uses tailshaft speed, final drive ratio and rear tire diameter to calculate vehicle speed. Again, the proper values must be entered into the setup
Max rpm for WOT should be set at least 500 rpm less than the engine's redline. This allows some time, as a function of rpm, for the shift to complete. A soft transmission or loose converter will exaggerate the shift time delay at WOT.



Jake's feedback is spot on since there really are no shifters available for the 4L80E. Most are intended for 700's and 4L60E's. Typically, the end user has difficulty achieving full Park or full 1st gear. If your buddy never had a problem reaching Park, then he needs to adjust in that direction. The computer doesn't have much influence here other than a wacked out TPS reading that is applying too much line pressure at a low throttle angle.

If all this sounds like rocket science, have your buddy call me and I'll do my best to set him straight on the tuning. We no longer support TCI products except for pre-existing customers, but it sounds like he really needs some support. Tuning is actually very easy.