| i think the cans are the same, just the pipe work is different.
dont honestly know how much difference you would get. my 's' with a 54 system is practically the same as andy b's 'r' with a 57. he has literally 2 more bhp at the peak but i actually have a bit more lower down. torque is comparable.
if you wanted to see the charts they are on the board somewhere. will try to find the link. |