Diablo Sport - increasing trans pressure

[14burrito]

Merry Christmas everyone.

 

Got an intune i3 during black friday to get rid of the crap idle (really all I wanted it for). After messing around with it I ended up turning torque managment off and I increased shift pressure across the board about 5%.

 

Prior to, my trans temps would be 120 with amb temps around 50/60 degrees. Since the parameter changes in seeing a consistently higher temp from the trans.

 

The few degrees freeway isn't much of concern, but I did want to ask and hear what others experiences are with city driving temps after increasing the line pressure. I'm gaining a few degrees at idle (in gear) and I'm gaining a few degrees during light acceleration. I'm not able to shed any once reaching cruising speeds so the slight temp gains simply compound on each other. My usual drive profile now results in a 150F doorstop temp vs my usual mid 120s.

 

Anyone have thoughts, experiences or first hand insight? I expected some increase in temps but honestly wasnt expecting what I am seeing.

 

Thanks for the comments!

 

2019 Tahoe 5.3l 6 speed with grill shutters

[CamGTP]

I don't know what Diablo actually does when it comes to Torque Mngt changes and line pressure changes because I only know how it to do it myself with HP Tuners.

 

These trucks are torque based systems for everything. If torque mngt is off then it changes how the transmission functions. I never mess with TM changes when tuning a 6 speed because you simply do not need to even touch it to make it do exactly what you want it to do. Torque Mngt is used to pull power (torque) away to help complete the shifts, do upshifting, downshifting, torque converter lock up etc etc. Perhaps is causing a little more torque converter slip and heating the fluid more but that is just a guess.

 

I'd guess that the handheld thing doesn't let you pick what gears the torque converter can function in, change specific shift time settings or on-coming pressure presets for shift speed. Without that you can't really fine tune it. I turn off the converter for gears 1-4, speed up the shift time and increase the on-coming pressure presets for the clutches to make the shifts crisper while really never touching the actual shift "line" pressure settings.

 

If you turn the TM back on and things return to what they were before, then you found out that was the reason.

[14burrito]

8 minutes ago, CamGTP said:

I don't know what Diablo actually does when it comes to Torque Mngt changes and line pressure changes because I only know how it to do it myself with HP Tuners.

 

These trucks are torque based systems for everything. If torque mngt is off then it changes how the transmission functions. I never mess with TM changes when tuning a 6 speed because you simply do not need to even touch it to make it do exactly what you want it to do. Torque Mngt is used to pull power (torque) away to help complete the shifts, do upshifting, downshifting, torque converter lock up etc etc. Perhaps is causing a little more torque converter slip and heating the fluid more but that is just a guess.

 

I'd guess that the handheld thing doesn't let you pick what gears the torque converter can function in, change specific shift time settings or on-coming pressure presets for shift speed. Without that you can't really fine tune it. I turn off the converter for gears 1-4, speed up the shift time and increase the on-coming pressure presets for the clutches to make the shifts crisper while really never touching the actual shift "line" pressure settings.

 

If you turn the TM back on and things return to what they were before, then you found out that was the reason.

 

Thank you, that was exactly my plan for tomorrow - TM going back on and I'll keep the +5% to see what happens. I was thinking it had to have been slip, couldn't imagine what else would be causing heat under those specific conditions when cruising doesn't generate much more. Shall see how the ATF behavior changes based off the one change. Thank you

[14burrito]

@CamGTP TM = on didnt help.

 

It was already "heat soaked" but I put the line pressure back to stock. Cruising I was able to shed some heat but at idle and light accel was gaining. 

 

Resorted everything back to stock and shall see what happens. 

 

About 20k ago I did a 6qt rejuiv on the ATF and sent a sample out to Blackstone. Blackstone said the sample I sent in looked great (questioned it being new). Was thinking of doing another 6qt exchange in the next month or two.

[14burrito]

FWIW 

Same drive, same amb temps, stock tune = relatively constant ATF temp freeway with ability to shed a degree or two on light downgrades; overall ATF temp to my door net 12F lower.