I don't know about you guys but I find 7500rpm is a bit to little for the fast revving FXO. If possible please raise it to 8000-8500 rpm. or maybe better 9000 rpm
7000 for the GT/WRX (211-250 hp) and STI 2.5 litre engine, 8000 for the STI two litre engine.
Anyway, even if I do like high reving engines, I don't see much point in increasing the rev limit for the FXO. It uses a turbo engine which doesn't gain that much from reving higher (in real life).
If you think you're going through the gears too quickly, change the gearing.