Wanting to upgrade non-turbo impreza with sti engine?

Question

I have a subie without turbo (rs 2.5) which I'm thinking of upgrading to sti engine. Now I would like to know whether anyone has ever done that? consider my car use a different ecu is that means i need to buy a new ecu for turbo engine? should I get oringinal or after market brands? where can I find these people that can do the tuning. Thx guys

Answer 1

Those cars are pretty much the same as far as mountings and bolt patterns and such. Many people swap engines and transmissions regularly even before the STI trim was available in the U.S. The best information about tuning would be on Australian websites. Google and you'll find tons of information, everything is in english and the Aussies love subaru's and love to help out.

I would just build the RS block and buy the STI upgrade parts (many boosted RS's on the street). As far as ecu's go, I would go full standalone with all the goodies. But be warned, the scooby doo's are an advanced tuner's car and the best pick for heavy duty off road racing.

Answer 2

Sti Turbo Upgrade

Answer 3

check out http://www.nasoic.com quite a few transplants there. Personally you'd be better off just buying a used STi, but if you got an itch, the transformation is possible. Also, as was previously noted, I'd stick with upgrading to a wrx motor, or a JDM 2.0l STi unless you want to change your ENTIRE driveline. The USDM 6 speed throws a monkey wrench in the works because it has a different length, and a different output ratio(and there's no way your RS tranny would survive an STi motor). For an EJ25 transplant you'll need motor, tranny, ECU, main shaft, rear diff, front and rear half shafts, rear hubs, rear brakes, just WAY too much hassle. An EJ207 transplant would be a nice one, and it isn't too hard to get 300whp out of 2.0l(PE1820 will do nicely).

I looked at the same thing with a WRX wagon, I was at 330whp on pump gas and wanted more. I was planning on going to an EJ25, a non DCCD 6 speed, and a few other goodies, then realized all of the other hassle involved and decided to sell my wagon and pick up an STi. I am SOooo glad I did. After a GT35R and a few other minor goodies she lays 438hp to the ground on a mustang dyno(which is about 550 at the crank), has great brakes, great suspension, and is one SEXY beast. With wingless trunk, RS hood, and black APS FMIC noone ever guesses they are about to have their ass handed to them by a cute little 4 door. You should be able to pick up an 04 STi in good shape for right around $20K

Good luck either way.

Answer 4

If you have a 2.5rs pre-2002, get an ej20(wrx) engine. The power to wieght ratio would be great. Plus, since the motor is already turbo'd, it's not hard to unlock noticable power gains for low money. You can find wrx motors for relatively cheap, and they are pretty easy to find, along with ecu's which usually run a few hundred bucks. In addition to the motor you can get a custom tune and full exhaust piping and be above sti power levels. You should go to nasioc.com and post your questions and look for tuners in your area if you are serious.

Answer 5

Also, the stock Impreza is a SOHC engine and the Sti's is a DOHC. That means that along with everything listed above by [Tim H], you would also need to replace the valvatrain. I agree with the person before me, you're much better off to just buy an Sti.

Answer 6

It would be easier and maybe cheaper just to buy a STi. Dont forget everything that you need to upgrade if you go from 160hp to 300hp. You will need a new transmission, transfer case, axles, and driveshafts. You should also get bgger brakes. All of these parts with labor will get you a STi.

Answer 7

save it maintained in tiptop condition, greater healthful the ideal tyres for speed and eliminate any extra weight that's no longer necessary. you additionally can do some thing like replace the chip interior the engine administration device to optimise overall performance yet this might cut back gas intake, advance your coverage expenditures and impact reliability.