6L50 Shift Pressure help

I have increased the torque of my 2.8 Duramax truck about 20% with the engine tune now I need to address the trans and I'm learning as I go.
So I guess with this extra power I'm going to slip the trans more that it should and could cause damage?

Should I increase the shift pressures for each gear, what is a starting increase 10%?
And what about the Max Line Pressure?

Also if I lowers my shift speeds do I need to then adjust my TCC apply/release speeds?

TCM T43

Thanks for any help
Attachment 104091

Leave the MAX line pressure alone, I've never touched that on stock or mildly modded V8 engines with 6 speed auto.

Increasing the shift pressure slightly for gear is fine, I do that all the time.

I tend to lower the shift time torque adder (shift time) down to around .3000 for a nice shift without being too fast and I also slightly up the oncoming pressure presets for gears 1-4. Doing pressure changes like that means you need to reset the adaptive presets in the computer using the VCM scanner after flashing and prior to driving the vehicle. This way the new changes learn.


Adjust the TCC settings as you wish. It's up to you if you want the converter locked/unlocked at different speeds and if you want the shifts to happen at different speeds.

Thanks 5FPD what’s the process with the reset, in park key on?

It's the same as always, flash the tune, open the scanner and connect to the vehicle and use the special functions tab to reset the presets.

Ok when I push reset nothing happens I thought it might say complete or something?

Correct, nothing shows up. Click reset and then preset, that's it and start the vehicle. If it worked you'll notice it on the first couple times through the gears as it adjusts.

This is HP Tuners we are working with and not a GM Tool designed for the vehicle.