BikerDarren24

Hey guys, I'm running a 2.5" bore cat back at the moment, Is their any major differences in getting a 3" bore cat back apart from better flow and being ready for a true 3" TBE system.

Thinking of a new cobra exhaust and have the option of 2.5" or 3" bore.

http://www.cobrasport.com/exhaust/Su...1-07%29/31/0/0

SB03 Subaru Impreza Turbo WRX and STI (01-07) - Cat-Back System (Non-Resonated)

Any advice or opinion would be magic guys.

RICHARD J

iTrader: (4)

2.5 is good for over 500 & can give better spool. You'd gain more with a decat of sports cat.

BikerDarren24

Thanks man, so there are differences but mostly with bigger engine modding, mines is basically stock.

Thanks man

legacy_gtb

iTrader: (3)

Nicer raspyer noise when not oversized for your power too!

As said, till you get to 480+, 3" is overkill!