Been chasing a detonation issue in my '12 JCW Cooper S (N14 engine). The last attempt to fix included a coil replacement and a "software update"

The car drives differently now! The boost hits in a more linear faction and my butt dyno swears the car is slower! Car is totally stock.

Thoughts?

 

It could be just the power coming on in a more linear pattern that makes it feel slower, or the "update" they did for you was actually a power deration, much like removing the JCW software..

Had you just gotten out of the Vette and found this car to be slower than you remembered?

 

I hardly drive the vette. I had gotten out of a horrendous base model clubman loaner.

If they yanked the jcw software, how would I prove so?

It surges when the turbo spools but then just goes kinda flat.