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.

 

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

 

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

Thanks man

 

Nicer raspyer noise when not oversized for your power too!

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