See Bill Harvey at Exiter (NH) Subaru.

Generally speaking the standard EJ25 2.5 Liter open deck engine block that is used in the Impreza RS isnt especially well suited for serious turbo boost.
Given the amount of time required to turbo the engine, settling for a piddling 4-6 PSI of "safe" turbo boost isnt really cost effective (although it has been done), Therefore most people will tell you that your best bet might be to hunt down an older EJ22T engine and work from there, or maybe transplant a totalled WRX engine, Turbo, ECU (etc...) into your car.

Neither option is especially cheap.

 

well, in a subaru, you wont find many other options, than turbo's. or nitrous. superchargers are pretty much scarce. but a wrx engine will drop right into ur car, and all u will need is a totalled wrx to do the transplant. and dont worry, their easy to find.
if your not knowledgable about transplanting yourself, there are plenty of gear heads on this forum to answer all of your questions, and maybe even help you out w/ your project.
if you wanna stay with your engine, theirs not much else to do to it to get substantial power gains, but a turbo kit is available, and it will give u about 6psi of boost which will bring you up to about 235hp to the wheels. after that, its major engine work to gain more power.
so you have 2 choices. me and my friend have been studying these, and found out that the cheapest of them is to transplant the wrx motor. so its up to you.

 

Danielle -

I *think* I vaguely recall Subarurabbit (Roger) posting something about an Australian (Carpa ? Capra ? Cappa ?) Supercharger a few years ago, although it might have been a purpose built kit for the 2.2 liter engine. You might want to PM him for more information.

Basically though I think the Phase II EJ25 has plenty of decent - although certainly not staggering - mid-range torque, so that for normal driving situations you have more than adequate power and good (if not great) gas milage.

What are your performance goals for a blown subie engine ?
Top speed ? low speed drivability ?

Bill Harvey, Wayne (wac), Edwin (Efoo), Kurt (Darsu ?), Mark (Fitz) and maybe a few other semi-local folks (that I can't think of at the moment) all have extensive experiance with turbocharging the EJ25 and/or EJ22 motors. While they have some wonderfull performance results, I think most of them have also experianced more then their fair share of blown head gaskets, turbos, and a few semi-serious blown motor internals to make the whole turbo experiance seem rather daunting.

For sure picking up a low-milage totalled WRX EJ20T engine, ECU, and sub-frame crossmember is the most reliable means of obtaining more reliable horsepower. On the other hand if all you really want is a tad more low-end punch, then you might be better pleased with a supercharger.

Also a few others Longshot (Korey) and Patrick Olsen have expirimented some with better breathing, less restrictive exhausts, and leaning out their fuel air mixtures so as to produce some really notisable and relitively cheap performance improvements as well.

I think most people will tell you that the first (and cheapest) thing you can do to improve your performance, would be to invest a few bucks in some perfmance driving school training. A couple hundred bucks spent on a weekend up at "Tim O'Neils" school, or a few other places, will give you the biggest performance improvements while also making you a much safer driver as well. The skills you learn there are also transferrable to other cars you might drive in the future.

 

well, you deffinately made some good points, but for BIG power, the best idea is the wrx motor. me and my friends are not just about getting small amounts of power. around here, everybody competes for the fastest, but most unique ideas in the car mod scene. my friends legacy gt is quite fast as is, and has kept up w/ the likes of turbo talons, and eclipses, but he wants more punch, and of course, the fun of having a turbo on the motor, and all the benefits of it,and the electronics that come w/ it.
theres something about pushing buttons on a boost controller, and getting amples more horespower w/o spending a dime more money, unless the boost is too high for the motor to handle.
a wrx motor can handle about 16-17psi of boost, and as being as the stock boost limiter hits at 14.2psi, there is much more potential boost for the motor to use.
as for the ej25, it is a great platform for a boosted motor (hence the new STI) so im sure w/ a little work on internals, and a good snail shell (turbo), an ej25 would smoke wrx's all day long.
but the money factor always comes first.
my advice..... buy a wrecked wrx, and transplant.
its fast, easy, and cheap, and deffinately braudens your horizens for more performance parts.

 

Most Subaru dealerships exist to sell cars, not to modify them. Yes most dealerships would not approve of such a swap. There are very few "mod freindly" dealerships, and of those that are in this area, I think that Exeter (NH) Subaru really stnads out as having enough qualified mechancis to do such a "swap" properly. Another place you might want to look into is "Rallyspec" (?) somewhere in New Jersey, I think.

While I cant quote you what these places will likely charge, my guess is such a transplant could easily run you between $3,500 to $6,000, depending on how good a negotiator you are, how cheaply you can locate an engine from a "totalled" WRX, and what sort of additional modifications you might want over and above the stock WRX powerplant.