I have a a Redtop SR20det, tub. manifold, stock turbo, downpipe, testpipe, and the Apexi N1 catback. The Exhaust isn't really that loud, but it can get annoying on the highway. What would be the most effective silencer, without killing that much horsepower? High-flow cat, resonator, what is your opinion?

 

definetly try a silencer they usually come with them. i had a blitz nurspec cat back and when the silencer was in it was really quiet.

 

use the silencer
add another resonator
hi flow cat would help or a resonated test pipe (projectnissan.com)

or get a different exhaust. n1's are loud, thats about it.

 

another resonator would help i think the "in can" silencers make the exhaust sound too high pitched... but its up to you.

 

trade me for mine, i think mine is to quiet

 

The two best solutions have been mentioned. Changing the testpipe to a high flow cat will cut down a LOT on the noise. After that, an in-tip silencer will cut the noise. The best part is that neither of these require you to cut/weld on your exhuast (like adding a resonator).

 

Try a HKS Hi Power. Mine is quiet and sounds awesome. They even make a Hi-Power silent. It's supposed to be a lil quieter, but I dont know how much.

 

take it off n go back stock if you wnat quiet

 

i had the z fever high flow cat and it made my car loud so i switched out to a megan test pipe very quiet now till the wastegate opens

 

The best things is to remove all your carpet and interior in the back and put in sound deadening and/or dynamat. Then put everything back in and put a silencer on.