Hi everyone,
I was referred to this by several people on the CTS-V forums, and they suggested this might be the best place to ask about a transmission tuning question.
I finally finished my 2011 CTS-V A6 build. It made 642 rwhp on the Dynojet, and I’m extremely happy with how it turned out. The car was completely stock before the build, so I know any change in transmission behavior would have to be tune related.
Before I ever started the car, I shipped the car to a local tuner here in Washington who dyno tunes LS-powered cars. The car runs fantastic, makes great power, and the shifts themselves are firm and clean with no flare, so overall I’m very happy.
The only thing I’m unsure about is the transmission behavior in normal Drive (D). It behaves exactly like Sport mode. In D it always starts in 1st gear, and every downshift coming to a stop has rev-matching, which can make it a little jerky in city driving. When I move the shifter into Sport mode, I honestly can’t tell any difference—it behaves exactly the same as Drive.
I’m not against it if that’s actually the best way to keep the transmission alive at this power level. I just don’t know if this is intentional or if a TCM setting was changed that effectively has the transmission in Sport mode all the time. I did not touch transmission it is stock only thing is fully serviced with a new Chevrolet torque converter
I can certainly talk with the local tuner, but I honestly don’t know what to ask for or which settings to have him look at. The guys on the forums all felt it was most likely a tuning change and suggested I subscribe and ask you since you have so much experience with these cars.
I’d really appreciate any insight you can provide on whether this is normal, what might cause it, and if there’s a way to restore a difference between Drive and Sport mode without compromising the transmission or the engine tune.
Thank you very much for your time. I really appreciate any guidance