borrowing me mates g-plate rs turbo over this weekend but there seems to be a problem. when u give it some the engine cuts back about 3-4000rpm aand theres no more go unless u let ya foot off then reapply. even then it only climbs a little until doing it again. its the same in every gear. almost like theres some sort of limiter cutting in. as far as he knows the car is completely standard other than a 3" magnex exhaust. any help would be brilliant

dave