i was wondering if their is any difference between a stock 05 wrx exhaust and a 05 sti exhaust and would it make any difference if i swap them out (mid pipe and muffler)
I believe that they follow the same path and are roughly the same size. However the STi muffler is much more free flowing than the WRX one, IIRC. keep in mind that the stock STi muffler is still pretty restrictive, but less so than the WRX one.
would it be a waste of time to put it in then...... nice to see that im not the only one up this late
it says Sti on the tip. that should be enough reason. Lots of folks do it. it's not going to hurt if you get the Sti system for a good price service industry...that's why i am awake now.
I would hunt around for a good deal on a stealthback and hook that to a quieter axleback like the sti axle back or a better flowing aftermarket axleback that's reasonably quiet. Then you will have decent gains with a mild change in tone if that's what your after. You would need a tune with the downpipe but with some bargain shopping and a road tune you could easily finish up sub 500$.
The midpipes are the same (same diameter, sti I think has a larger resonator), but there is a difference in the mufflers. The sti muffler has slightly larger diameter piping (diameter matches the midpipe, wrx muffler is smaller than midpipe) and the baffles inside the sti muffler are less restrictive. On my 03 wrx with a stage 2 tune, I can tell a big difference between running an sti muffler vs wrx muffler (quicker spool, better throttle response with sti muffler). On a stock wrx, you probably won't notice much of a difference.