Expanded Tables for T87/8L90s

Does anyone think we will eventually get the tables and mapped PIDs we need to completely and properly control the newer transmissions? It seems like most people are satisfied and think just by disabling desired TCC slip tables and not allowing for the 8L90 TCC shutter problem to happen that they've fixed all the problems.

Yes I know we have access to the shift scheduling and lockup but I think the factory shift points are perfect. It's the horrendous driveability and inconsistent shift feel especially at part throttle that is one of the problems. The low speed driveability will have to be fixed by adding in some sort of throttle follower to keep the drivetrain loaded, but the part throttle clunks on upshifts and downshifts and the inconsistency in shift feel between different gears I feel can be fixed with more tables and GM just sacraficed a lot in the driveability department probably for reliability. Or maybe its just from sorry tuning from beauracracy.

Maybe with all the new ECUs being untunable we will get more support for our existing stuff. I know adjusting shift times and inertia never does anything since eventually the addaptives end up cancelling out your changes. It could also just be a fundamental hydraulic or mechanical flaw but so far I've gotten nowhere in trying to improve the shift quality and driveability of my 8L90 in my Camaro even though I hear all the time is a tune will fix all your problems, but all we can basically change is when it shifts and TCC lockup?

For the truck 8l90 and 8l45 it would be nice to have access to the traction control and abs vss stuff. Otherwise changing gears or tire size eliminates cruise control and makes the traction control very finicky.

I completely agree if we could get access to the CCM or whatever controls the launch control and traction control instead of working around it and limiting it in the ECM, this would help us a lot I think.

A lot of this I don't have direct evidence or proof for just how it feels, but 95% of stuff we have access to to change honestly seems like it makes no difference or either it is negated my some other parameter somewhere that we don't have access to.

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Originally Posted by cmitchell17

I completely agree if we could get access to the CCM or whatever controls the launch control and traction control instead of working around it and limiting it in the ECM, this would help us a lot I think.

A lot of this I don't have direct evidence or proof for just how it feels, but 95% of stuff we have access to to change honestly seems like it makes no difference or either it is negated my some other parameter somewhere that we don't have access to.

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Can you post a trans file for a 8l90 so i can look at it?

Attachment 91870

That is a 2015.5 Yukon Denali L86/8L90E

Attachment 91894

Here is what i'm currently using. I just feel like the shift time tables pretty much are just a placebo effect, especially since I don't know of any way we can monitor the shift correction feedback loop. The only PID's we have seem to not give true values, the values they give are not close to what you have commanded in the tables, and we also don't have an error PID to monitor and we only get 1-2, 2-3, 3-4, and 4-5, no downshift times or skip shift times.

If you compare a ZO6 corvette 8L90 file to a camaro or a truck you can see downshift times are a lot lower, sometimes .2 seconds lower in higher torque areas. But if you try to copy and paste these times you start to get a tie up thats bad enough to trigger traction control/stabilitrac on a WOT downshift to 2nd. So there has got to be other tables we need. I don't want to try a full flash to a ZO6 OS since I haven't heard of anyone doing it on a T87 or if its even supported.