I have a segment swap done on my turbo 4.8l with a stock 4l80e with a triple disc 258mm circle D 3600 stall converter. After today's outing at the track, I had some questions (Tune, Config, and log attached).

Of note:
**I am commanding the converter to lock in 2nd and 3rd gear.
**I am utilizing the tow haul button and its respective tables for my track passes, so if looking at the tune be sure to look at the "performance" transmission tables.

1) I am commanding the converter to lock after the 1->2 shift (it appears the lockup mph is based off the ISS, and it locked mid 1->2 shift). The converter locked in 2nd, then unlocked at 71mph, then locked again at 84mph. Why?

2) I have shift lock disabled, however the converter is staying locked during at WOT through the 2->3 shift. What should I change to have the converter unlock for the shift?

Despite the transmission issues, the truck ran a new PB of 11.59sec@115.9mph.

Thanks for the help!

 

Nobody?

Could it be a solenoid or internal issue that may be responsible for the converters locking/unlocking at WOT?

 

According to your TCC Slip % there is no lockup in that log when you are rolling at 100% TPS...slip % stays high.(can you log TCC Mode with HPT?..Off, Enabled, Applying, Locked, etc). And how is there 0% slip when you are holding it at 3500RPM/ 0MPH on the brake? Something is not right.

 

Thanks for the response Dr X.

I haven't done too much logging for transmission parameters until I started tuning WOT lockup speeds.

The TCC% slip is definitely wrong. In the log, when PWM is 99-100% the converter is locked.

Any thoughts as to what the issue could be, or even how to diagnose it?

Thanks!

 

Did you double check the ISS wiring?

Was the Seg swap done with 2.25 Beta?

Yes, it should be locked at 99%. I would log more trans parameters....ISS, VSS, TCC Mode, Gear, Slip RPM, Engine RPM, etc.

 

Yes. It was swapped with 2.25 Beta...is that good or bad? HA! I'll do some more reading, log more parameters, and see what I can come up with.

Appreciate the help man!

 

Should be good...have seen some people just copy/paste tables and think they did a seg swap. I built myself a tune with 2.25 Beta but never got a chance to try it out. Had been running on EFILive til now.