I literally do not know what to do next. I've had this thing to the dealer 4 times for detonation issues under full throttle between shifts.
The 1st and 2nd time they claimed "could not duplicate". The 3rd time, they cleaned the combustion chamber, i.e. didn't help at all. The 4th time, they flashed the computer. It helped but there is definitely noticeable spark knock as it shifts between 3rd and 4th and WOT running 89 octane.
When we first bought the car with 20,000 miles on it, we attempted to run 87 octane as specified. Whoops....wrong answer. I actually thought the motor was going to be toast after 1 tank of gas. I tried 91 octane and it almost went away completely except for between shifts. Well, I kind of got fed up with sinking 91 octane into the tank for no reason, so off to the dealer it went. They claim that "snap throttle" is going to produce spark knock as well as in between shifts. They claim the computer isn't fast enough to retard the timing. Bullshit! My performance is gone since the reprogram and it's still pinging. I was thinking about supercharging, but if I can't get rid of the pre-detonation running 89 octane with no mods, how could I expect to run a blower on 91? I know a reburn will be required, but I think there are other issues causing the spark knock.
Does ANYONE have any suggestions?
Marc