I own a 06 Impreza 2.5i~I wanna modify its exhaust w/ fgk(Fujitsubu) RM-01A~I'm wondering if the WRX one can fit on my 2.5 'cause there doesn't list any product for 2.5~

 

NO. 2.5i's have 2.25 inch system WRX has 2.5 inch and STI 3 inch.

 

i have an 05' sti exhaust on my 2.5i o_O seems to work fine for me, u just have to extend the mid pipe about 2 inches. been wondering though if its ok to put an sti exhaust on a 2.5i

 

I'm going into Midas tomorrow, to swap on a Sti catback onto my 2.5i.
That should be interesting.
Btw, the Sti catback i'm swapping has already been modified to fit a 2.5rs.
Woot!

 

I went to ask an engineer who works in the dealer today. He said 06 WRX's cat back should be the same as 06 2.5i's.

 

how much hp difference gain from an sti catback and wrx catback. if the sti one can fit, i think i'm going to do that. isn't the piping larger n' all. idk.

 

No HP gains at all.
The only difference => Sound performance.

I just got the Sti axelback installed onto my 2.5i.
The catback did not fit.

FYI : This is a confirmation, that the STI catback does not Bolt on perfectly.
You require bending and welding of the flanges, and extending the piping.

I would of gotten the catback, but this was a straight up trade for my stock catback, and my stock catback didn't fit on the other suby, so we accepted it and just traded the axelbacks, rather than the catbacks.