6L80E TCC Lockup Questions

[Longslyde]

Hello Guys! New to this board and just picked up HP to tune my 6L80E tcc. I have the "other" tuning software also. I got this software because of better support for this transmission. I have a 2010 GMC Sierra 4WD, 6.2L, Whipple Supercharger, "Pterodactyl" 6L80E (Alto Clutches Welded shafts, etc.), 2500 Billet Stall.
I have tuned the TCC slip table to zero and disabled tcc adapt. I have now gotten rid of the constant 100 rpm on/off slip at cruising speeds. It will stay locked with 0 slip as long as I do not move the throttle pedal (increase TPS). When I move it even slightly, it will slip (about 100-150 rpm) until the movement of the pedal stops then immediately lock up again. Is there a way to keep it locked with 0 slip on slight acceleration?
Also, when the transmission goes into lock up it takes a long ramp time (like 2-3 seconds) to go from the intiation of the lock up to full lock. It just slides into lock. I would like it to engage as fast as possible. Is there a way to do this? I have already maxed out the TCC pressure ramp table with no luck. And I did test to make sure the converter actually holds by engaging PWM on the DVT controls. It does not slip at all when engaged. So I do know it has to be in the tuning, just not sure what table to look at in HP. Thanks for help in advance guys!

[TimC]

Change the TCC offset to 90. You'll get 60 psi as the min TCC so it will lock up solid and not slip. I'm running my STS-V this way and it works great.

[Longslyde]

Thanks TimC! Just to verify, you are talking about TCC Pressure Regulator Offset correct? Do I change anything in Regulator Gain also?
I'm not sure what the factor means when Regulator gain is at 1.5 factory and can be set up to 8. I would think the higher the number, the faster it would reach either offset or max pressure. Does that sound correct?

[carlrx7]

subscribed!

[TimC]

That's the offset I was talking about. I have not messed with the gain but I'd be interested to see what happens. If you are going to change it make sure you log it in the scanner so you can see what happens.

[Longslyde]

Ok guys! Anyone with an aftermarket converter must read on... I am now 100% confident my converter will not fail due to slippage now.
I've been fighting with the fact that my converter would go in and out of lockup under even slight throttle. It would lock then under power would slip 150-200 rpm. I knew this was not going to be good in the long run. Through many logs and trial and error, I have found the solution.
I did not disable TCC adapt. Make it work for you. I set the minimum to 0psi and max to +100psi. Set TCC Regulator Offset to the value that you want to be the "minimum" Line pressure, then set TCC Regulator gain to "1.0". In my case, I set the offset to 90psi. I might get by with lower PSI but this is what I chose to run with at this time. It will now lock instantly with no ramp time. that was a problem I had also. It would just Sliiiiiide into lock. In my logs, when in lockup, it will not drop below 90psi and under movement of the throttle, it will take the pressure up to 109.9psi (max) then back down as needed but not lower than the offset setting. 0 slip on the converter the whole time.
This has NOT been tested with WOT TCC apply enabled. I personally do not believe in locking the converter on wide open throttle, especially with a supercharger. Just my 2 cents, not looking to get flamed on that comment.
For those wondering, taking the regulator gain to 0 will just make the line pressure maxed out constantly. Taking it to "8" will keep if from locking at all. The higher the number in this area, the lower the TCC line pressure will go. I felt constant max pressure was not needed for my application, but feel free to do what you wish.

Video of how it works:



I hope this helps people out there who have the same problem I had. I had been searching for this answer for months. Take care guys!

[bluegoat06]

Great info, thanks a lot for your tests.

Question for those of us still running the stock verter. Do you guys forsee any issues that may arise setting the TCC regulator offset to 90 with a stock verter ? i've alredy zeroed out the slip rpm by gears, but i see the same behavior as the OP, when the gas is pressed slightly, slip rpm would go to 90-130rpm. if anything i'd think even better mpg compared to the way i have it, but i'll rather check first

I'll also assume that if i set the tcc offset to 90 with the stock verter, that i should avoid the tcc lock that GM allows in the factory tune ?, my TC locks in 4th gear in Sport mode, and also 3rd and 4th while in manual at WOT, but there is a minimal slip as well, so i would think setting the tcc offset to 90 would make the stock verter lock in full as well at WOT, which i'd guess won't be a good thing.

[TimC]

Won't hurt anything at all. Go ahead and try it. Engagement will be a lot harsher.

[bluegoat06]

Thanks a lot Tim, how about the WOT portion ? Do you think i should avoid locking the tc at WOT like if i had an aftermarket single disk unit ? or the stock unit would be able to work on full lock using the stock lock values ?

[Longslyde]

Thanks a lot Tim, how about the WOT portion ? Do you think i should avoid locking the tc at WOT like if i had an aftermarket single disk unit ? or the stock unit would be able to work on full lock using the stock lock values ?

I personally wouldn't lock the stock verter on wot especially if you have power adders. I did it on my unit before the tranny upgrade and found it to be pretty harsh. Even if you have TCC set to unlock between shifts, it will be harsh since theres not enough time to bleed of pressure to cushion the shift. At least it seemed that way to me. I just felt it was pretty hard on the verter. YMMV.

[TimC]

Lock it and see what happens. log pressure and adjust. My converter is stock with relived clutches. The 258 units in caddies are dual disk. It slips 100rpm at 573/621 rear wheel.

[bluegoat06]

I personally wouldn't lock the stock verter on wot especially if you have power adders. I did it on my unit before the tranny upgrade and found it to be pretty harsh. Even if you have TCC set to unlock between shifts, it will be harsh since theres not enough time to bleed of pressure to cushion the shift. At least it seemed that way to me. I just felt it was pretty hard on the verter. YMMV.

No power adders for me, she's pretty much stock, CAI, exhaust, etc.
For the G8's, the factory commands lock for 4th gear at WOT in sport mode, and in manual mode as well, she locks 3rd and 4th at WOT.
The stock calibration also allows the verter to slip some while locked, thus the question i had if i change this tcc offset to 90, she would have zero slip rpm at part throttle while cruising, which won't be a problem, but she should also have zero slip at WOT, which i've never tried before, and the only thing that concerns me since i have the stock unit.

[bluegoat06]

Lock it and see what happens. log pressure and adjust. My converter is stock with relived clutches. The 258 units in caddies are dual disk. It slips 100rpm at 573/621 rear wheel.

What pressure should i log to make sure things are not going crazy with tcc offset set to 90 ?

[TimC]

Log tcc pressure and converter slip. Nothing is going to go crazy. Lockup will just feel like an old school converter locking.

[Longslyde]

TCC line pressure. You can select it as a pid to log. It should go max under WOT if settings are correct. Then it will back down when you back off the throttle. but should stay at 90 minimum if that is what you set your offset to. After you get it setup you can experiment with lower pressures to see if there's slip. I ended up going to 80PSI offset in my Sierra but that is a lot heavier vehicle and less aerodynamic. You may not even need that much. You will learn how the pressure gets distributed at different throttle positions once you log that pid and can adjust accordingly. Good luck!

Edit: LOL TimC! We must have been typing at the same time. +1 on what TimC says

[bluegoat06]

Thanks again guys. i'll give it a try tomorrow morning. i'll start at 50 offset just to see how she behaves. i'm already logging tcc line pressure to see when the verter locks, and slip rpm to see how much slip is in there. I thought you guys were referring to a different pressure pid all together

[bluegoat06]

I loaded a new tune with the tcc offset set to 50psi this morning. So far she's doing better than with the factory 26.5

Before the change, the TC would lock, but it would have a 10-20rpm slip below 70mph, zero rpm slip past 70mph, after the change, the slip is zero while the verter is locked below 70mph, and can also accelerate with the verter locked and the tcc slip goes to about 10-20rpm slip, then goes to zero again very quickly. i guess this is why i don't feel the tc being harsh when engages.

When the verter is locked, and i give her enough gas to unlock, the feeling is pretty much like a car with overdrive, gear remains in 6th for example, but the rpm jumps 500rpm higher, then locks again smoothly.

Also did a 3rd WOT run to test, and the tc locks, but it would also slip, (100rpm or so), i need to check in my old logs to see if the slip at WOT remain more or less the same.

Very happy about it, and i'll keep the offset at 50psi for time being. Again, thanks a lot for you guys tests on this matter. :thumbsup:

I'll post the logs later this morning.

[Longslyde]

Awesome! Glad it worked for you!

[TimC]

The offset is just the minimum amount of pressure applied to the converter when it locks. It will not affect full throttle unless the computer was applying less than the new offset value, which is unlikely.

[bluegoat06]

Here are a couple of print screens showing the before and after, thanks again guys.

Stock TCC Offset


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50 PSI TCC Offset


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And this is WOT, 50Psi Offset, 3rd gear, manual mode


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