8L90 Downshift TCC Unlocking and Trq Mgmt

[Haans249]

Good Evening,

Setup: 2016 Camaro SS A8 with a Circle D 3600 stall, NA 530rwhp (FBO/H/C/I)

I am working on my TCC lockup and shift scheduling to get things dialed and have noticed a couple items in this process.

1) No matter what I set things to for TCC Apply/Release, when I go WOT for a downshift into a lower gear (in this case from 8th to 3rd in the log), my converter unlocks for the downshift, but stays locked on upshifts (3-4). This can be clearly seen in the log attached where there is an initial spike in pressures just as the commanded gear rolls, then pressure releases, TCC slips, and finally pressures return, and converter re-locks. I have tried adjusting the apply mph in the tune to 45 mph, but TCC still releases. Is this simply the normal function of the transmission and no way around it?

2) As you can see in the log, when 3rd gear engages, I consistently and always get a quick full torque management and spark reduction for a brief moment (traction control is fully disabled). I have adjusted my torque tables, adjusted transmission torque management torque reduction settings to remove that spark reduction to no avail. Am I missing a specific setting that will get rid of this? I can hear and feel a brief dip in power when this occurs at WOT and is annoying.

Thanks for any tips!

[Haans249]

This thread has a decent number of views, but no responses.

I did some more work the past two days and I believe I have some really solid results. I thought I had disabled all torque reduction "safety settings" on the trans, but I had not. I disabled ALL of them, and now my downshifts are rock solid and FAST. I also disabled all of the TCC adapts.

For anyone with a Circle D triple disk converter and 8l90 who wants a very nice and smooth part throttle driving experience (with soft TCC apply at part throttle), you can use the settings in my tune. Part throttle shifts and TCC apply is very tame and "comfortable" for a 232/240 cammed vehicle.

Attached is my updated Tune and Log. (note: I'm investigating the KR i'm getting at shifts).

Enjoy!

[yellz06]

Good Luck

[Haans249]

Good Luck

What do you mean? I've got it driving perfectly now with very smooth TCC apply at part throttle normal driving and solid shifts with no torque management issues at WOT on a Circle D triple disc converter that is made for WOT lockup. Am I missing something?

[hjtrbo]

Am I missing something?

No torque reduction on upshifts

[Haans249]

I turned all the torque management settings back on and it didn't make any difference in shift speed at WOT but it certainly did reduce torque when shifting (no more wheel spin at 80mph), so i'll leave it enabled. However, part throttle shifting is now really lazy - is there a way to disable part throttle shifting torque management? Otherwise I'll need to redo all of my part throttle shift points...

[hjtrbo]

Glad you turned TM back on.

Here is some good tables that will help get you in started. Will take a while to get TM adder dialled in.

-1 = No torque management
0 = Full torque management

[Haans249]

Glad you turned TM back on.

Here is some good tables that will help get you in started. Will take a while to get TM adder dialled in.

-1 = No torque management
0 = Full torque management

Appreciate the response! I did a little more digging through the calibration and found two tables that I think will get me where I need much easier then the Adder Modifiers. I will test the changes tomorrow and see if part throttle shifting trq mngmt is disabled from the tables I attached. The stock calibration has it set to 0 for minimum torque (default enabled) and for minimum tps is set to 2%, also basically enabled by default. Will change the TPS minimum first, and if that doesn't work, then will try the minimum torque, and if that doesn't work, i'll just grenade the transmission.

Upshift Torque Management.PNG

[Haans249]

Glad you turned TM back on.

Here is some good tables that will help get you in started. Will take a while to get TM adder dialled in.

-1 = No torque management
0 = Full torque management

The tables I posted above had zero effect on part throttle trq management. The table you posted for the Adder worked great. What I did was zero out 1-2, 2-3, 3-4, 4-5 above, then changed the same under the adder to 1.0, then used the adder modifier table to disable trq mgmt at anything below 3,250 rpm and 100ftbls of driver demand. Worked great. Now I have crisp shifts at part throttle and full trq management on WOT run (still spinning tires slightly at 88 mph though).

[hjtrbo]

You're not supposed to 0 out the cells above. That's another was to turn off torque management lol.

Merge these torque management changes in to your current tune. Then just adjust the adder modifier

[Haans249]

Appreciate it. My settings did work as intended though. I don't get any noticeable torque management in part throttle driving which has really smoothed out part throttle shifting. But when I go 40-50%+ throttle, torque management kicks back in on upshifts as expected (even in 1-5 gears where I zeroed out the Torque Factor). I'll give your settings a try and see how it works. This might be one of those areas that works both ways.

[Haans249]

I did some more testing today. I have attached images of the results. The first settings are utilizing the suggested settings that you provided and I found that torque management is still fully engaged, even after trying to disable them with the Adder Modifier. The only way I was able to reduce the torque management at part throttle was to zero out the Torque to 0 in the gears as shown. This, along with the Adder modifier table was able to get torque management down to a level that is imperceptible at part throttle. Both graphs are at the same scale, so you can see that the amount of torque management is engaged for a longer period of time if leaving the torque set to 1.0.

Also, zeroing out the Torque setting, but including the adder modifier (with further refinements in the Modifier Table) below still resulted in full torque management at WOT runs, so the top Torque settings do not completely override the torque management, but work alongside the adders.

I'm not sure what your testing has shown specifically or what transmission your settings worked, but on mine it looks like the calibration adds to what is in the torque table, so if you leave them at 1.0 and then put the adder at 1.0 and disable the adder with the modifier table, you're still going to get full trq management of 1.0.

Upshift Settings 1.PNGUpshift Settings 1 Results.PNGUpshift Settings 2.PNGUpshift Settings 2 Results.PNG

[hjtrbo]

Must work differently than 6L90.

[joe111599]

This thread has a decent number of views, but no responses.

I did some more work the past two days and I believe I have some really solid results. I thought I had disabled all torque reduction "safety settings" on the trans, but I had not. I disabled ALL of them, and now my downshifts are rock solid and FAST. I also disabled all of the TCC adapts.

For anyone with a Circle D triple disk converter and 8l90 who wants a very nice and smooth part throttle driving experience (with soft TCC apply at part throttle), you can use the settings in my tune. Part throttle shifts and TCC apply is very tame and "comfortable" for a 232/240 cammed vehicle.

Attached is my updated Tune and Log. (note: I'm investigating the KR i'm getting at shifts).

Enjoy!

Thanks a lot Haans! I've been trying to get my 8L90 smoothed out and happy for normal driving conditions. I must say there's a TON to look at on these 8L90's and you can get in a tailspin QUICK. My biggest issue was TCC lockup and shift scheduling.

I will let you know how it goes. Thanks again!