[PooBoy]

I am interested in reprogramming the transmission to shift more quickly and harder. Has anyone attempted such a modification? What other vehicles does this tranny come in? Anecdotally, I am pretty sure there are 3 - 5 tenths to be had by this mod if its done correctly.

 

[IXLR8]

Check out the most common modification, the Vector Motorsports ECM/TCM tune. You will like it!

Not as good but easily reversible, Superchips programmer for G8. (you will chirp the tires)

 

[chiefpontiac]

First make sure yours is not an early vehicle eligible for a TCM upgrade. Vehicles built in the early months thus affected were supposed to get "fixed" before retail sale but there is no guarantee it was done on every unit by the selling dealer. Your dealer can tell you IF the vehicle falls into this group, and IF any fix is available - there was also a TSB related to an improvement to be performed ONLY upon customer complaint.