IF the combo is set up to make HP "up there"..... IF not, then power drops off and the car slows up. I've played "shifting" games at the strip, and there is a happy spot for every engine. Can you spin it more??? Yep! I spun a 340 7200 RPM's and slowed up a 1/2 second vs 6000 rpms. It's wherever the power band is set up to run. BUT, you don't NEED 8500 rpm's to run 9's. To many of them doing it at 6500- 7k.