Well i have driven the car for a day now wiht the RPM on there and i am surprised at how much my power band moved up. Its a pretty noticeable difference from the performer upper. A lot of the low end snap is gone, but it still pulls really hard. Before when i would stomp on it from first at say 2,000 rpm or so it would just rip the nittos loose. Now it hooks until around 3,000-3,500 or so then it will break them loose. Also it really does seem to tear a lot harder to 6,000 than before, I wish i could have some dyno numbers or track times to compare the two, but i never got a chance. I will be at the track this saturday to see what the cars got in it.