I have race mode on pretty much all the time and havent noticed the difference when changing it on and off. However, I have noticed that changing the gearbox into sport mode raises the idle RPM slightly and gives it a bit of a grumble at a stand still. Re-enabling race mode switches the gearbox into sport by default so i'm guessing this is whats happening here? Something else I've noticed is that if you put the gearbox into manual without enabling the sport mode then the throttle response when letting off is much less harsh. If you enable sport then go into manual you will notice that letting off the accelerator is much more harsh and almost throws you forward.