The 18" is pretty quites (except on cold start, but no obnoxious) and has a nice deep tone when you get on it. I doubt the 12" res or no res is that much louder. With RTPs or HFCs you should be good to go in terms of limited to no rasp.
Now you got me debating on whether or not to get the 18" res on the 3"............killing me guys!
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 2007 350Z NISMO #0618: Zerolift | UPREV | F.I. | Greddy | Competition Clutch | Injector Dynamics | Aeromotive | Pioneer | JL
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