6L80E 3-4 slow.

[IDRIVEAG8GT]

Hey guys. I've got a 6L80E in an 08 G8 GT, and on high speed WOT runs going from 3-4th it takes forever to make the Gear change. Like a good 2-3 second lag where the car just quits pulling and then it slowly makes the change and starts pulling again. I have all Torque Management Disabled and I'm doing everything via Shift Times which is going well. But, I have this issue. So what do I do to fix it? And how do you work with the shift time Inertia Adder tables?

Thanks
-Robbie.

[Google]

Hey guys. I've got a 6L80E in an 08 G8 GT, and on high speed WOT runs going from 3-4th it takes forever to make the Gear change. Like a good 2-3 second lag where the car just quits pulling and then it slowly makes the change and starts pulling again. I have all Torque Management Disabled and I'm doing everything via Shift Times which is going well. But, I have this issue. So what do I do to fix it? And how do you work with the shift time Inertia Adder tables?

Thanks
-Robbie.

prolly somthn in the tune we don't see posted causing the problem.

[IDRIVEAG8GT]

Ok OK! I'll post the damn thing :P Happy??

[Google]

have you tried lowering your shift rpm/mph for the 3-4? I have not study'd ur tune but will keep looking into it.. most 3-4 or 2-3 lag is a conflict in the tune some were..

[Frost]

Does it just do it in sport mode? It's my understanding that it's supposed to happen in sport mode (at least it's the OEM's intent). It's anticipating the re-application of throttle.

[bluegoat06]

OP, have you tried to replicate the issue with the stock trans tune ?
If you load the stock trans tune, take a log where it shows the 3-4 shift and post it here. include vehicle speed,rpm, current gear, etc.

[IDRIVEAG8GT]

Will get on this ASAP. Just finishing up my Cam/Heads job on it. It does it regardless of D, SD, or M. It's like it slips! I'll try loading a stock trans tune though and see what happens.

[Randy K]

Check fluid level. I'm not sure about your specific ride but my Corvette requires that the fluid level be checked when the fluid temp is between a range of (IIRC) 78 degrees F - 122 degrees F.

I did a H/C swap. I also had the 3 - 4 slop/slip. The fluid level was full at 170 degrees. Once it cooled down to the required temp. I found it was 22 oz. low. I filled it and the slip went away.

[midevil1]

i dont know what gear you have in the diff, but you are short shifting 1-2 and 2-3 and then you have your 3-4 shift maxed on mph and a 6125 rev limit....not going to jive.

[IDRIVEAG8GT]

Check fluid level. I'm not sure about your specific ride but my Corvette requires that the fluid level be checked when the fluid temp is between a range of (IIRC) 78 degrees F - 122 degrees F.

I did a H/C swap. I also had the 3 - 4 slop/slip. The fluid level was full at 170 degrees. Once it cooled down to the required temp. I found it was 22 oz. low. I filled it and the slip went away.

That may be the cause. Never even thought about fluid. Thanks.

[IDRIVEAG8GT]

i dont know what gear you have in the diff, but you are short shifting 1-2 and 2-3 and then you have your 3-4 shift maxed on mph and a 6125 rev limit....not going to jive.

Mmmm there's 2:92's in the diff. My first to second is good because it raps so fast the TCM can't keep up. Second to Third, I see what you're talking about. I'm addressing that. And Third to Fourth well it shifts at the right rpm it just poops out Fourth to Fifth though is good. And Fifith to Sixth, well I've only ran it to 170 with the new cam and heads so far so it's not going to poke that gear in for awhile.

[wreckwriter]

Not sure what the issue is but I can tell you for sure it is in the tune. Bluecat fixed mine.

[Waker]

You might have burnt up the 3-4 clutches. Based on your power level and your lack of torque management on a stock tranny, that's my best guess. The 3-4 clutch in this tranny is the weakest and usually fails first. Turn TM back on and see what happens. Leave your shift times alone and let the ECM pull timing. Good luck

[IDRIVEAG8GT]

Hey guys I fixed it! Thanks for the suggestions!

[morgan72]

Hey guys I fixed it! Thanks for the suggestions!

What did you do to fix it?

[IDRIVEAG8GT]

There was an inertia multiplier table that I set to 0 and it is perfect.

[bluegoat06]

What table was it?

[IDRIVEAG8GT]

I forgot but it was under "Upshift Special" Apparently it multiplied everything by 1.5.

[G8-4-speed]

I forgot but it was under "Upshift Special" Apparently it multiplied everything by 1.5.

You can change the table to negative values if it needs any more help.

[IDRIVEAG8GT]

So far it seems good, I don't want it to bang 3-4 anyways, right now it shoots it in nice and easy and there's no delay or hesitation.