OK, so far...the car is MUCH faster. Like I uninstalled it today (more on that soon) and I'm honestly having withdrawals....
Throttle response is much much much much much MUCH better, and frankly the car pulls pretty hard through second gear....but the trouble starts here, when you enter 3rd gear.
The car slips.....pauses.....then SLAMS into 3rd. I have had experience with tuning diesel trucks, my mom's G8 has torque management taken out of the tranny and some other performance goodies, I had an Impala SS with a programmer and firm shifts, they all pale in comparison to the jerk this made.
This only happens at 75% throttle and up (roughly). In all IDCS settings (which has been cooperating with the tune so far). Drive the car normal and it feels normal.
I decided to let it be for the night, drive it work in the morning and see how it goes.
The drive to work, was simply awesome. I gradually laid into the car, in small increments. Half throttle for a few miles here, a little bit more when I make it to nichols rd, a little bit more when I make it to sunrise hwy, basically giving the tranny a chance to get used to it. After about a half hour I was confident enough to do some full throttle runs from 30 and boy oh boy did the car reward me with great power and smooth shifts. It's crazy how well it pulled at 70mph.
I e-mailed Vince about the shifts anyway, he said it has been an issue (intermittently) with the cars he has tuned so far. The explanation is the transmission module is deciding that the car is receiving too much power and cutting the throttle....in the middle of the gear and at other unusual points. Making ti feel like the car is shifting and causing it to shift badly when it does. This is most apparent at the 2-3 shift because you're usually not at full throttle for the other shifts.
This problem came back at lunch, either from the shorter run time or from the heat (100 degrees!) and 5 minutes into my drive home my check engine light came on.
Uh oh.
I called OnStar, they said "It is an engine/transmission code, the turbo has performed unexpectedly". Well that is vague. I pulled into a gas station and switched the car back to stock and told Vince about it, he said it is likely an underboost code. Another customer got one (his car hasn't). This is most likely thanks to the torque management issue, the TCM is requesting a cut in throttle and opens the bypass valve when the ECM is still asking for 20 pounds of boost. Hence underboost.
He has a solution running in the car for the torque management but is waiting a few more days to send it out to make sure he has that bug ironed out.
I'll update you guys when that happens.
