6L90 downshift and pedal sensitivity...

[243]

Howdy, I have a 2010 2500HD 6.0 4x4 that is stock, 3.73 gears and ~31" tires that will be swapped for ~33" in a few months.

My tuner should arrive today and I hope to have it setup and at least save the stock tune and getting familiar with the function and controls before the end of the weekend. My first goal is tuning the transmission to dial torque management back and confirm the tune has the correct tire size/gearing inputs correct. I bought Master EFI Tuner a few days ago and that is how I will start along with the forums.

This is my first LS vehicle and first GM with an overdrive, I have driven manual transmissions since 1999 with the exception of the T400 in my Cherokee.

My question today is to address a particularly annoying aspect of the transmission. When cruising at around 40-50 mph the trans is typically in 5th gear, if I want to downshift to 4th and accelerate I start adding some throttle but after steadily depressing the throttle it may travel ~40% to the floor accelerating slowly in 5th and then the trans downshifts to 3rd and I want to correct this. It's especially annoying to passengers who may be taking a drink or staring at their phone when the truck jumps and snaps their neck or spills their drink.

Is this issue correctable by gear for down shifts timing relative to pedal input?

And second, can throttle pedal sensitivity be increased across the board so that pedal input to output is faster?

Thanks!

[5FDP]

Yes, you could change how the transmission downshifts into the next lowest gear. It's a matter of changing tables that relate to the rpm/speed for the downshifts.


You have very very limited function of the throttle blade movement, they often can not even be adjusted as it will go into REP mode. On some vehicles you can adjust the opening rate at will but that only does so much because that's more of a torque mngt type setting to me.

You''ll want to keep the TM on the 6L80/6L90e nearly stock, they do not play very well when you remove it. Slightly decreases can be okay but often doing too much can make them shift and act worse than factory. Tuning them to get your desired shift speed and shift feel is not that hard once you know what tables to work with.

[243]

Unfortunately USPS delayed the fun, maybe it will arrive today.