My plans:

Pacesetter header into 2.5" flex pipe, then into 2.5" Magnaflow high flow cat, then 2.5" piping back to 2.5" PowerZ muffler.

Is that too much? I already have the flex pipe, cat, and muffler, and they're all 2.5", but should I stay with 2.5" piping, or reduce them to 2.25" between the components?

What difference would it make doing it one way over the other?

what engine do you have? and what do you plan on doing to it in the future?

there are lots of things to consider, if you're staying N/A then 2 1/4 is fine, but if you plan on going turbo or supercharger, then go 2 1/2 - 3.

an LD9 could use 2 1/2 while still being N/A, but more than that would just be a big waste.

my exhaust is 2 1/4, but i'm staying N/A, so it all depends on your plans for the future.

2.5 inch is too much for a 2.2 OHV that is NA
2.25 is good for that engine



Im a Xbox 360 fanboy...and damn proud of it!!

so could i still use the cat and flex pipe, and just have them put reducers at the inlets/outlets to 2.25"? It shouldn't hurt anything to use them should it?

the flow of your exhaust is based on the SMALLEST point in your setup... so no i shouldnt change anything.

I had full 2.25" Pacesetter header, magnaflow cat and magnaflow mufflers... worked fine N/A, even low boost it was fine(turbo mani instead of header)... starts to get restrictive when you reach higher boost though... just finished making my 2.5" kit all mandrel bent w/ off-road pipe as well. Just make sure you get it mandrel bent... you DONT want any restrictions...BTW hi-flow cats on N/A kinda make our cars sound ricy, not deep like w/ just a cat-back.








Failure is not failure if you learn from it