I have an 07 C6 Corvette with an A6 and as of last Saturday, newly installed 3.42 gears.
The car has several mods (cam, headers, CAI, 3000 stall) and my best time on a Wednesday night is 11.56 @ 122mph.
Using the tune from the 11.56 run, I changed only the gear ratio and let it do an Auto Scale of the transmission tables. So far so good, right? Nope, the best I could manage was 11.73 which was disappointing since I and several other people thought it would actually run a little quicker.
I'm not ready to blame the gears just yet because I noticed some weirdness in the logs from last night. Specifically:
1) The car refused to shift into second gear until it was past 7000 rpm. No matter how low I set it in the tune, it simply wouldn't shift when I told it. The only reason I didn't hit the rev-limiter is that I have it set to 7200. I know that I'm able to change the other shift points correctly because earlier in the evening the car surprised me by shifting into 5th right at the traps. When I changed that and ran the next time it stayed in 4th the whole time.
2) In some of my previous runs before last night, I noticed that the Injector Duty seemed to stay pretty much in sync with the RPM. If you look at the scan from last night however, that wasn't the case. Could this have anything to do with the car shifting way too late?
3) During the race my spark advance seemed somewhat erratic in the log. I checked this against prior runs and it's usually pretty flat which is why I thought it looked odd.
4) Is the 4.9 degrees of KR at launch normal?
Also, after changing the gears did I need to do anything more than simply changing the gear ratio in the tune?
Any thoughts or suggestions would be appreciated.
Thanks,
Christopher
P.S. I had the car tuned by someone in Chicago and just tweak it myself when I'm at the track.