loudness? perf gain if any?

i'm in search of a fairly quite catback. i don't want to attrach attension from the popo

 

I have an HKS on my turbo eclipse, its not to loud (no cat either), and the sound go's away after like 2.9grand on the tach, cause of the turbo kicking in, on my 240 nothing yet, but if its a NA motor then the sound will still rise as the RPMS mount up, but I'd have to say I love the sound of my HKS C-B setup.

 

I have a HKS Hiper catback on my 240, it's not as loud as I wanted it to be, but it's fairly loud. It gets louder from 3000 rpm till redline when full throttle, other times its mid range. I"m actually trying to sell it and get a Apexi GT spec cat back. 3.74 inches of one piece piping and no middle resonator. If any one is interested in my catback I might sell it for around $300 (bought it back in August) I live in Ga so if anyone lives around there, you could just pick it up, as I no longer have the box it came in. The box was pretty huge, barely fitted it in my car.

 

I ordered the HKS Hiper exhaust. It should come tomorrow. My 2.4 is turbo'd so it'll be quieter after 3k, so thats good for long trips on the highway. I'm lookin for huge perfomance gains because all i have right now is a 3" test pipe, 3" downpipe and factory catback Good luck.