at what rpm does the gt stop making power(manual)?
Same question for a gt with a saleen charger.

 

When I was running the stock NA setup, with just a tune and a CAI, I set the rev limiter to 6800 and hit it all the time.. Depending on the tune, power peaks out between 5500 and 6500 rpm. I have seen dynos where the peak is at 5500, and some where the peak is around 6200-6500.. Even if the peak is at 5500, you still have more power at 6800 than you do at 3500, so the longer you can go without shifting, the better, in a race. The limit of course is when you start damaging your engine.

With a positive displacement supercharger, your best power should come in at the max RPM of the compressor. The twin screw will make the same boost all the way through, so the power curve is similar to the stock engine in shape. However, once you go above about 6300, the stress on your rods goes up exponentially, so it is a good idea to ignore the potential point of peak power, and keep the revs down. Most twin screws level off around 6300-6500, but Roots and Centris increase boost as you rev, so the limit will be dependent on the capacity of the supercharger and when your rods will fail. If you want to stay in your power band longer get taller gears.

 

The car makes power all the way until you hit the rev limiter. The amount of power at different RPMs varies, but there is power at every rpm from idle to redline...