ETC closing with TCS off

[HartsG8GT]

The car is a Pontiac G8 GT cammed/supercharged pushing 600whp. The issue I'm having is when I go WOT I get lots of wheel spin, while spinning the trans doesn't want to upshift, it then bangs off the rev limiter for a few seconds until the car falls completely on its face. It feels like it just stops pulling like the ETC closes on me. It does this with trac control on or off. I have searched through my tune trying to figure out a table to prevent this but have had no luck. I understand the 6l80e doesn't like to shift with major wheel spin but the car falling on its face is getting annoying. Any help would be greatly appreciated.

[NICKY BOY]

Sounds like you have etc enabled as rpm limiter. Bottom line though is want to lower your wot enable
for shifting.

[HartsG8GT]

I have Spark and fuel cut enabled and ETC disabled for rpm control. I also have the switchover delay set at 5 seconds, but it doesn't matter if I set it at 400 seconds it still does it. I also have it commanding the shift at 5800 rpm and my rev limiter at 6900 rpm.

[Chris@HPTuners]

try logging the PIDs:
- ETC Source
- ETC TqMgt Type
- Spark TqMgt Type
- Fuel Cut TqMgt Type
- Fuel Cut Type

[HartsG8GT]

Thanks Chris I will do that tonight and load up the log file.

[HartsG8GT]

OK well here is the log I took. You can see at about 6.5 seconds where the throttle blade closes and the etc source reads idle, even though I still have the throttle mashed. While this happens you will see the engine loses all steam and the output torque drops to -46 lb ft. You will also see right before this the trans doesn't want to shift it sits there bouncing off the rev limiter at 7000 rpm when I should have shifted at or around 5800 rpm. I know that is a result of wheel spin. I'm officially lost, I'm starting to think the solution to the problem is to eliminate wheel spin, lol.

[Chris@HPTuners]

its the trans shift torque management

it looks like the trans is shifting 1-2-3-2-3...

[HartsG8GT]

Yeah i noticed that. Is there anyway to stop that from happening? Disable up-shift torque management?

[HartsG8GT]

I'm still confused, anybody have any ideas?

[thesubfloor]

I'm still confused, anybody have any ideas?

Let me see if I got this right:

• You're rolling along and at around 14MPH you quickly got to WOT (frame 192 when you get there).
• The car first hits the rev-limiter at frame 221 and rather than lift, you keep your foot into it.
• The engine comes off the rev-limiter at frame 240 which subsequently causes all kinds of crazy wheelspin (keeping in mind you still haven't lifted yet).
• 8 frames later you hit the rev-limiter again and then another 11 frames pass before you finally take your foot off the throttle.

And throughout all this you're actually wondering why the transmission won't shift? I know this is gonna come across wrong, but are you serious ???

Several things:

1. As it sounds like you already know, if you get wheelspin the 6L80 will almost never shift properly.
2. Lowering your shift RPM does absolutely nothing to control your shift points in these cars. If you want it to shift sooner then you have to lower your WOT shift MPH.
3. If you don't want Traction Control to kick in then you have to turn it off in the tune as hitting the switch for it will not prevent it from happening in situations like this.
4. If you've made any significant power additions to the car then you need to lower your shift MPH even further, basically giving the TCM more "advance notice" if you will of the upcoming shift. Basically, the more you've done to the car the more you need to lower your shift points to get the car shifting where you want.