Hi, everyone!

I am always doubt about HKS cat-back works better than the stock exhaust or not? These days I watched a scene it showed stock exhausts are much better than any other brand of exhaust systems; plus, the after-market bland made G35, which is on the movie, decrease more than 30 hp. I was totally shocked! However, how about if I just change a Helix down pipe, HKS up-pipe with stock cat back exhaust, the hp will decrease or incease? stock cat back works better or HKS hi-power?

Thank you!!

 

ok thats apples and oranges

NA cars need back pressure

your car doesnt need back pressure like an NA car

 

as I told u before, u should go with 2.5" piping instead of 3". Since you're not happy with the hks exhaust, I would suggest going with an Apexi N1 catback and some other brand of downpipe that is 2.5" instead of 3".

You don't need 3" piping for a stock turbo wrx.