Increase car speed

Hi i have modified the cars of the ferrari team with the GP4 Perf Editor and assigned a very high skills to the team and the drivers of ferrari, and now when i'm on the race of the qualify, i use raikkonen, massa gets very higher speeds, always win the qualifyins or the race with 12 seconds of advantage, what i need to do to, restore it to his normal race speed, or to increse the speed of my car.

thanks