impreza exhaust

on a 06' 2.5i..

does anybody know the diameter of the piping which goes into the inlet end of the muffler?

if anybody could help me in any way to get things straight with this little project it would be appreciated.

heres part of my thought process at the moment--
im thinkin of cutting off the welded stock muffler from the piping. then put on a muffler with a slightly bigger inlet diameter so that i dont have to weld anything. for example if the piping is 2.25....then maybe i would put a muffler thats 2.5 so that its a snug fit without welding. how does that sound?

comments, opinions, anything would be helpful......thanks

IIRC, the RSs up through 05 had 2.25" pipes, stock. Seems like they changed just enough random junk in 06 that it'd be worth getting down to measure it yourself...

Sticking a muffer on the end of a pipe with out welding it will lead to exhaust leaks at least, and most likely, your muffler will shoot off at some point. Please don't do that.

I have a 2000 RS, and I got a great deal on an STI axle-back take off muffler. Me and a friend chopped up my midpipe to align the flanges and butted up my 2.25" pipes to the 3" pipe of the muffler. Sounds great, probably no real performance gains, and the whole axle-back piece remains unaltered.

edit: to clarify, the cutting and welding I had to do was to rotate the flanges, because the orientation of the midpipe-to-axleback flange is different between turbo and non-turbo Subarus. Which means you have to pay attention to whether a part ia made for WRX/STI or for RS/2.5i. Then again, double check your own, because Subaru likes to change stuff.

for example if the piping is 2.25....then maybe i would put a muffler thats 2.5 so that its a snug fit without welding. how does that sound?


Sounds like a not very snug fit. There's a big difference between 2.25" and 2.5".

IIRC, the RSs up through 05 had 2.25" pipes, stock. Seems like they changed just enough random junk in 06 that it'd be worth getting down to measure it yourself...

Sticking a muffer on the end of a pipe with out welding it will lead to exhaust leaks at least, and most likely, your muffler will shoot off at some point. Please don't do that.

I have a 2000 RS, and I got a great deal on an STI axle-back take off muffler. Me and a friend chopped up my midpipe to align the flanges and butted up my 2.25" pipes to the 3" pipe of the muffler. Sounds great, probably no real performance gains, and the whole axle-back piece remains unaltered.

edit: to clarify, the cutting and welding I had to do was to rotate the flanges, because the orientation of the midpipe-to-axleback flange is different between turbo and non-turbo Subarus. Which means you have to pay attention to whether a part ia made for WRX/STI or for RS/2.5i. Then again, double check your own, because Subaru likes to change stuff.


thanks jay :thumbsup: , i think i'll just do the whole thing the right way instead of taking all the shortcuts i was thinking about before.