Boost the 2.5...no replacement for displacement.

 

Except technology .

 

pretty car!

 

No it isnt. The STi motor is a closed deck and has Dohc (if you can call them take) as opposed to the SOHC the 2.5rs has. The Sti motor has an 8.0:1 compression while the 2.5rs has a 10.0:1. It def cant handle boost as well as the Sti motor can. You'd be lucky to get 9psi from that block, stock of course. It would be a much wiser investment (cheaper too) to swap in the ej20 motor. Also, the transmission on the 2.5rs is actually from a 1.8 Liberty, it cant handle big horsepower either.

 

You're right about the tranny, definitely different. Plus you get the neato DCCD business if you swap it. I was always under the impression that Subaru only had two different 4-cylinder block designs, one for the 2.5 and one for the 2.0 engine, and they just swapped heads depending on which car it was.
I'm pretty sure though that the swap for the STi motor is straight bolt in, so if you got the cash it definitely wouldn't be hard to turn an RS into a pretty fast car.

 

Its true that they have 2 basic designs, with the major differences being the heads. But they also offer a closed deck and an open deck, the closed being far more boost-able. The internals of each motor differ greatly aswell. As I was saying before the compression makes a huge difference when wanted to safely boost those ej motors.

And yes, the STi motor will fit into the GC8 chassis, but not without some major upgrades to go along with it. You will need the whole drivetrain (transimission, axles, driveshaft and rear diff) along with the ECU (obviously) and all the wiring harnesses. After its all said and done, you will be paying roughly the same amount as you would for a New STi. Which hardly makes it worth while, considering it never stops there. The brakes will then need to be upgraded to handle all that extra power, and the suspension will definitely need an upgrade aswell. You also need to consider the misc. extras that will come as the project unfolds.
Im not saying that you cant turbo that motor, I too have seen it done many times before. But if you want reliabilty, swap in the ej20. Or dont and just do suspension. Its hard to beat those little cars around an exit with just some simple upgrades. Like I was saying, before, its one fo the most fun cars Ive ever driven, (aside from the EVO :rick: )

 

Yeap. Oh yes its a 4-door guys.


Nightshade- Very good possibility. I am going to research it first. Figure out whats best. Trying to find a good forum right now.

Very happy with the car by the way guys! its great!

Jon

 

Check out I-Club They have a lot of info about that car. Be warned though, they are kind of nerds over there. Glad you're enjoying the car. Its lots 'o fun!

 

NASIOC is better

 

Hardest part about the swap is the wiring from talking to a few people that have done the swap.