are you side stepping it or just slow letting of the clutch??
i think the best way to get off the line is i rev the car to bout 7000-7500 rpm, as you bout to let go of the clutch o tend to ride it a LITTLE bit to ease the shock, rather then side steeping which is causes alot of shock through your drive train, which breaks boxs,
it takes abit of practice to get your launching right,
although if you got money a dont care bout blowing your gearbox, just side step it