i tryed a standard gearbox , then blew lsd gearboxes etc but car always drove the best and handles the best with the quaiffe atb diff in my ib5 box. the quaiffe feels so good and grips properly, my car dont be all over the road it grips and just pulls off quickly, pushed it hard in the bends etc and hadles fine.. it has f1 eagle tyres. maybe you need new tyres or wheel alignment etc