Before I built my little rcsb I had a 2011 ext cab with a 6.2 and 6l80. Truck shifted great WOT even chirped the 1-2 sometimes.
A buddy of mine just stopped by after getting kooks and a Maggie put on his 2014 with a 6 spd. When it shifts it feels like the truck kills all power, shifts gears, then takes off again. I though the trans was the same in them? Is his tune that messed up and that far off or is the tuning for the new trucks that bad?

 

That's because it closes the TB on the shift, that's part of the engine tune. It has to be tuned out.

 

That's insane that GM would even do that. It's probably the worst problem with the new truck.

 

Not insane, they want the product to last and want everyone, everywhere at anytime be able to drive it.

 

Ok, I'll play Devils advocate to that. Every time a truck shifts WOT and the TB slams close then immediately open again that's wearing out the tb motor and putting more stress on an engine going from WOT-nothing-WOT again....

 

Ya but that TB is much cheaper then a trans. It's still a bunch of crap, because properly tuned a 6L80E transmission can handle a lot more than the stock engine

 

Can you set the tune to only use timing for shift TM on '14+ trucks?