I just traded my IX with AMS exhaust and hfc for my X. I'm really digg'n the quiet vs the hwy drone. I forgot what a normal car sounds like. I guess I'm getting old . Is the major restriction to the system the cat? Has anyone switched just the cat to a HFC and netted good gains?

 

i know ams gained 15hp with their hfc

 

HAhaaa... you and me both. My Nissan had a straight-thru 3" and was loud as hell.

In the interest of keep your X still quiet, I'd get the AMS cast O2 housing/downpipe combo, HFC, and the Works Stealthworks muffler.

On my VIII, I'm running a Works DP, HFC, and Stealthworks muffler. It's slightly deeper tone at idle, but the volume in the car is barely changed at idle or WOT. I hear more transfer case noise than anything at any throttle position.

I think on the X, doing what I said above will free up ~30-35whp and still be damn near stock quiet.

 

heh, my previous car was an 85 corolla with headers and a straight pipe. man the X is QUIET compared to that car.

 

stock exhaust is garbage... thier are relativly quiet performance exhausts... on my evo 8 i had an apexi world sport witch was quiet and netted me gains. search my friend its half the fun.