Tuning for automatic 4T45E

[Chris_WNC]

I've recently swapped my stock donor LAP with a LDK/6758 combo. Donor was an NA Automatic car.

I'd like to tune the transmission so that I'm revving a little higher for longer. That turbo really likes being over 3k RPM. Currently the auto is doing its damnedest to keep the revs as low as possible. There are time when I think is should down shift and it holds 4th until I'm pretty much at WOT. Fun, but not practical.

Any tips, guides, or tunes you guys have to share with a noob?

 

[Desert Sasqwatch]

If you have HPT, contact them to find out if they have 4T45 tuning capability. I can't locate anything for performance tuning this transmission - lots of performance parts - but nothing to change programming with a cursory look through the web pages. Keep looking, you may come across something and might have better luck looking at European sites.

 

[devianteng]

I'm seeing several posts around 4T45E tuning on the HPT and CSS forums. Doubt you'll be able to do anything with buying a MPVI interface, but once you have that you should be able to log and see things like shift times and shift pressures:

https://www.cobaltss.net/forums/2-4l-le5-performance-tech-46/savvy-4t45e-tuners-324616/

4T45E Shifting

This is stock tune 27354 This is turbo install start tune 27355 This is tune in car 20% line pressure increase 27356 config and logs posted below

forum.hptuners.com

If you want to find someone to help you with remote tuning, I'd ask around in the Cobalt Facebook groups and see who has experience doing so. You'll still need a MPVI to flash the tunes, though.

 

[Chris_WNC]

I've got the MPVI2 and credits. I'm just not sure what to start changing.

 

[Chris_WNC]

I remember reading that thread that was linked. Those are some nice guys.

 

[Joebob]

Like what the link stated in it. You can start with a HHR SS with the TC/Auto option. Be mindful as to the speed at shift with relation to the final drive ratio and tire diameter differences. Haven't dove into it but I also pulled a stock tune for the V6 G6 auto option.

Joe