Quote Originally Posted by sheepo
hmmm so whats the proes and cons of a 4-2-1 and a 4-1? i'm certain there is a reason why there are 2 such system of piping... o.O, sorry still learning X_X
like i said:"
mate the design of 4-2-1 and 4-1 is got to do with the exhaust flow. it got to do with primary runners, secondary runners of the pipe. the length of them. it is designed to affect your peak torque landing at certain rpm range.

what gear box you have will have an impact as well, what final drive you have, will have an impact as well... what race you are in, will have an impact as well