6L80E Pids and logging...

[Longslyde]

Hello guys, I did some searching and did not come up with any answers, so i appologize if this has been covered somewhere else....

I have upgraded my 6L80E transmission with the alto red clutch packs, welded drums, 300M shaft, and 2400 billet Stall converter. Now need to to tune this transmission to ensure it will last. My stock unit did not hold up to 10 PSI whipple on the 2010 6.2L Sierra 4wd. (clutches started to slip after a couple hundred miles even with some pressure mods.) So I am wondering if there are pids in the works to monitor adaptive shift cells (much like LTFT's) and see where I am over or under pressuring the shifts and packs. i added pressure to all shifts and made sure to leave enough time to complete them and have the transmission almost feeling stock again with TM left on. Still 2-3 shift is slightly harsh at certain rpms but I am guessing that may be attributed to the damper removal and shaft upgrade. (Not sure on this.) it's not a harmful shift but it bangs in a little more than i'd like to see on a vehicle this heavy. Are more pids in the works to really disect this tranny? Thanks guys!

[Longslyde]

Is there anybody that has in-depth experience with this tranny? I need some input on the 2-3 shift flare I am getting under light load. It is like the tranny goes to neutral then bangs into 3rd. Takes about a full second to complete shift when it's commanded at .1750 sec. I've adjusted line pressures with some success. Just unsure of what line pressures and shift pressures these trannys work well with. Especially modded ones. I believe the stall is causing the issue since the shift problem is when I'm on the throttle slightly and the RPM is higher than the factory stall would be. When i try to keep the rpms down to where the factory converter would run, the shift completes faster and more responsively. Anybody out there have the tuning on these figured out? I've done quite a few engine tunes, had a lot of headaches, but I am certain this tranny was made up by some voodoo witch doctors or something.... Thanks for the help guys!

[Tre-Cool]

under desired shift times, i have set all my input torque mods to 0.0 this gives nice firm,quick shifts no matter what throttle your at.

i think the issue with the slow shifts, especially when forced induction is concerned is the e38 and t43 talking to each other cant seem to work out the required shift time delay based on the torque figures being generated.

however this is no excuse not to have worked out your actual base desired shift times.

[Longslyde]

Thanks for the info! I was thinking it was a bad thing to run with zero's in the input mods, but now realize the base timing is where the problem lies with that.
Have you changed anything in the line pressures or shift pressures? And does line pressure affect the holding power of the clutches in this tranny? Thanks!

[Longslyde]

Ok, In my OS 24254909 (2010 Sierra 6.2L 4x4 6L80E), there are no tables for base shift timing. If I zero timing in the input torque mod tables, will this set desired timing to 0.0000? If so, I know that is bad for the 6l80. Are there tables in the system that I am not able to see with this version of the software?

[Longslyde]

Can anyone see BASE shift timing tables in 24254909 OS?

[gmh308]

under desired shift times, i have set all my input torque mods to 0.0 this gives nice firm,quick shifts no matter what throttle your at.

i think the issue with the slow shifts, especially when forced induction is concerned is the e38 and t43 talking to each other cant seem to work out the required shift time delay based on the torque figures being generated.

however this is no excuse not to have worked out your actual base desired shift times.

Did you get this sorted TreCool with the shift under boost slowness?

[Redline Motorsports]

Not for nothing but its kind of related......before you can do any trans cal work you need to make sure your engine calibration is SPOT ON! The trans is torque based and reported torque comes from the engine controller....if your MAF and VE surfaces are off good luck getting good torque values.

If you look at most of the pressure tables they are referenced from torque....the difference between a reported torque of 350 vs 400 can be huge and significantly effect trans shifting and life....

Just something to be aware of before you start chasing other crap and fry a trans.....I see this happen all the time!

Howard

[joecar]

+1 what Howard said, this is very important (for both A6's and A4's).

[Longslyde]

Ok. I will have to go back and retry the tune to make sure I am on the money there. Just before I changed the tranny, My tune was good, or so I thought. shifts from the stock trans were crisp and smooth. Then, after the trans change with the Stall, everything kinda went to crap. So I started chasing the transmission. I will go back and see what I can find.
On another note, can anyone verify if all 6l80e's use the same Valve body? (not Tcm, I know that is different). I cannot find any reference material on that subject and since this was a core transmission when it was built, I'm a little concerned. Reason being, I occasionally here a hydraulic noise on downshift like the valve body hangs up or has a restriction. It could be the tune there too since i may be putting more torque to it than it thinks. Any help there would be appreciated. Thanks guys!