it's not the power but the gear ratios you have to worry about. If you change the gear ratios then you might have to worry because as far as I can figure it out all they did is get a formula down for if you're at this RPM in let's say 3rd gear and you down shift then this RPM is where it needs to be on the down shift according to the gear ratio difference. 500 horsepower isn't going to change that gear ratio so you should be fine !
