Aha!  So you can answer the debate that rages (on other forums) about whether OEM and/or aftermarket Impreza/WRX/STi exhaust systems fit into/under the stock under-bumper opening on a 92x.  Yes?

you got any pics to show us?

M8 wrote:

Lastnight I removed the Scoobysport muffler and replaced it with the muffler from an 04 STI. As much as I love deep rumble of the Scoobysport it's nice to be low profile again. So now I have a modified "stealth-back" exhaust: Scoobysport up and down pipes, factory 3rd cat left in place, Scoobysport mid-pipe into the STI axle-back. The Sti unit is quite a bit bulkier and heavier than the Scoobysport, but fit is perfect. It's tip is larger too, but it is nice and quiet until WOT. All you can really hear now (that distinguishes the car from stock) is the whistle of the turbo under load.

What does WOT mean?

I don't like loud, juvenile-sounding exhausts, and I prefer a sleeper car, so I'm thinking about doing the same thing you did, except I'd be putting on an STi cat-back exhaust, instead of just the muffler.  A local hi-performance shop recommended using a cheap, non-flex HKS up-pipe ($180) and said that pretty much any cat-less down-pipe would work with the system.  I'd be combining the modified up-pipe and turbo-back exhaust with a Cobb AccessPort.

What are your thoughts on 1) flex vs. non-flex up-pipe, 2) brand of up-pipe, down-pipe?  Why did you choose Scoobysport?

akaryrye wrote:

WOT = Wide open throttle

As for uppipe, i have a stock wrx uppipe on the way that I am going to gut out and swap.  Cost me $40 US on ebay and testing has shown that there is virtually no advantage to getting an aftermarket piece

Do you have any links to the testing data showing no advantage of an aftermarket up-pipe over a gutted stock pipe?  The mechanic/general manager of a local hi-performance shop said that the problem with gutting a stock pipe is that the gutted section of the pipe that used to house the catalytic converter has a larger cross-sectional area than the rest of the pipe, introducing air turbulence, which, while not totally negating the increased airflow, does not allow for the same amount of air that would pass through a uniform-diameter aftermarket pipe.

I actually would prefer a gutted stock up-pipe b/c it would be invisible to Saab service in the event of a warranty claim.  But, if you run the risk of damaging your turbo from not absolutely 100% removing all traces of destroyed cat, and you don't really get the same improvement as from an aftermarket pipe, I'm thinking I'd probably go aftermarket.  But, if you have literature stating otherwise, please let me know!

Edit:  BTW, why not just gut out your current stock up-pipe?

Our up-pipe has a cat in it, correct? A co-worker has a buddy with an STi and he just put a TBE on it. I told him to get me the STi's muffler and up-pipe because I thought I had read previously that the STi's up-pipe would bolt right up but doesn't have a cat so that would help in minor airflow? Obviously nothing significant but if I can get it for hella cheap, it is still better than stock right? Does anybody know the I.D./O.D. of the STi's stock exhaust system including up-pipe and everything?
Dan

Yea if I remember correctly he had replaced his up-pipe already. If the STi's don't have a cat in the up-pipe, what is the point for the STi owners to replace the stock up-pipe? Is it just too small or would they typically not replace it? Thanks for your help. By the way, as far as sound I know you said it's quiet until you open 'er up...does that mean there is really NO change in sound while idling/accelerating normally or is it a little deeper a slight bit over stock?
Dan

There's a good FAQ about uppipes and the WRX here:
http://forums.nasioc.com/forums/showthr … did=443943

It has a link to post on clubwrx where someone dynoed his car with an aftermarket uppipe and a gutted stock uppipe and got virtually the same numbers.

If I am careful, will a tech be able to tell I was in there? I plan on using a gutted stock pipe, so it will look identical, but what about marking-up the nuts and bolts, etc.???

///M

Poppakaylee wrote:

If I were to replace the stock uppipe in my 92x aero with a stock WRX STi uppipe am I to assume that they would look virtually the same (with the subaru brand?) and that the STi stock uppipe has no CAT right?  This sounds like a great way to get aftermarket uppipe results using what I assume the dealers would view as stock parts.  did I get it right?  where can I get a STi uppipe?

I believe they look very close, if not the same. As is said before, they show up for sale now and then (can't figure out why). But keep an eye on the classified section of www.nasioc.com they are usually cheap! $50 or so...

If I remember correctly, the STI downpipe is the same as ours.  The restrictive porstion comes w/ the blank plate "opening" where the downpipe mates to the turbo.  Replacing this with a bell-mouth or divorced waste-gate downpipe increases flow.  This is why Cobb's Accessport stage 2 is accomplished with replacing only the downpipe.

T-St Saab wrote:

If I remember correctly, the STI downpipe is the same as ours.  The restrictive porstion comes w/ the blank plate "opening" where the downpipe mates to the turbo.  Replacing this with a bell-mouth or divorced waste-gate downpipe increases flow.  This is why Cobb's Accessport stage 2 is accomplished with replacing only the downpipe.

that is correct. STI d/p = WRX d/p = 9-2X d/p