got 3" decat downpipe and 3" centre then on to 2.5 afterburner vortex troube i had is now centre pipe knocks against rear diff ........now as its after market and the oem hangers have been on a while i used cable ties around the rubber hangers to support the whole exhaust better but still get odd knock on hard turning right ..........any 1 else had this problem? idea i had was to buy stiffer hangers and mabye add new cable ties with new hangers .....stopped off a demon tweeks and guy there told me new hangers would,nt do anything just use loads of cabe ties.......