6l80e Slips in Sport Mode Only

[TeeWX]

I've got a 6l80e with a Circle D 2800-3200 converter in a G8 with an LS3 and I've noticed the car is slipping after it gets into 3rd gear from the 2-3 shift but this seems to ONLY happen in Sport Mode, which uses Pattern A. TUTD and even regular Drive don't seem to have this issue.

My fluid level is overfilled 1 quart past the GM level. This seems to be a common recommendation.

My car has had this trans tune for 7 years (not done by me) and I've only really played around with sport mode shift points to make it hold gears a little more aggressively. Otherwise I haven't touched it. It looks to be tuned using the older methodology before we had virtual torque tables. It worked fine on my old build, but I put a new LS3 crate engine in the car recently and noticed this issue while tuning after break in.

I've attached a log with a WOT 2-3 shift for TUTD, Drive, and Sport mode. Attached also is my tune file.

Is this more likely to be something with my tune or the trans itself? If it's the tune, where should I start?

[hjtrbo]

As a rough check add 20% then 30% to airmass A and see if it goes away. If good then can dial in better later.

[TeeWX]

As a rough check add 20% then 30% to airmass A and see if it goes away. If good then can dial in better later.

I'll give this a shot. Any idea why it would only slip like this in sport mode, and not drive and manual mode?

[hjtrbo]

Pattern A -> Pattern Y has the lowest shift pressure. Probably explains your issue.

Try this tune, it should wake it up a little bit. Adapt reset / preset. Take it for a learn drive. Then hammer the fuck out of it.

[TeeWX]

Pattern A -> Pattern Y has the lowest shift pressure. Probably explains your issue.

Try this tune, it should wake it up a little bit. Adapt reset / preset. Take it for a learn drive. Then hammer the fuck out of it.

Gave this a shot. Here's a log. It still has the weird behavior where it drops RPM after it starts to pull in 3rd gear. This doesn't happen when in manual mode as seen slightly later in this log.

Is this trans slip or something else? What would cause the RPM to rise to 5000, then drop back down to 4700 after getting into 3rd?

[hjtrbo]

Both shifts look nice and crisp. Its your torque converter locking. If you'd stayed in the manual pull for a bit longer it would have done the same thing.

You have the regulator gain to control initial apply. If that doesn't work then ask hp to see if they can add the desired pressure table to your OS.

Torque converter tuning is very subjective. To avoid the pull down, lock it in the gear before about 10km/h before the shift. See what that's like. Also can use the bluecat tool.