hi lads my mate REX has got a 4x4 escort cosworth big turbo and he has had a prodlem with it ever sins he bort it . its pushing about 300bhp at the mo but when you floor it hard in 1st and 2nd it has a flapping sound from under the car . its only as the car hucks up and is fighting for grip then it goses ..........has any one got any ideas wot it might be thanks