Did you buy this car used? Someone probably built a motor and chipped it separately. This can cause motor problems in the future. This is why I hate engine swaps and buying modded cars from morons who want to build an imitation of the faster model. The accurate redline GSR = 8100rpm, but fuel cut I believe is 8200rpm-8300rpm. A modded type would mimic it but would greatly expend the motor, pistons, etc.