View Full Version : Lowering Compression Requires Retune?

05-04-2009, 03:17 PM
Friend just changed his head gaset lowering the compression and is runing a FI setup on his m3 and I'm trying to explain that the tune he has was runing was for the stock head gasket and that he will now need a retune for his 12psi ... can anybody confirm this ?


05-05-2009, 12:46 AM
Well, It depends on how drastically the compression was dropped. If its really low and the car feels lazy it may need some additional advance or fuel or boost :D If its not much of a change I'd say it doesn't need to be re-tuned unless he notices a real loss in performance or drivability.