I have a MY99 Turbo Wagon and I was wondering if I could swap the engine for a WRX or STi version (prefrably STi).

Would this even be possible? And what type/year of engine would I need?

Has anyone done this or have any advice for me? I'm just testing the water for now but if it is viable, I might go for it!

 

You could swap for an STI engine. however to get the benefits you would also need to swap over the STI ECU as well or get a custom mapped ECU. It would be easier if you got an engine from the same year - the wiring loom and connectors should be similar.

Probably cheaper to install a custom mapped ECU

 

Firstly you need to determine why you want to swap the engine? If its because you want more power then a relativly simple process of free flowing exhaust and air filter. fuel pressure regulator or larger injectors and a bigger turbo, then remap. Then hope your gearbox is up to the job.

As far as engine transplants are concerned there are lots of variables.
Long engine
Short engine

firstly the short engine = just the block minus the heads.
there are many derivatives 2.0 - 2.5 with a few in between. These blocks are a straight swap for yours and you can bolt your heads on and ancils and your away.

long engine = block + heads
depend on which year this comes from depend on how difficult it would be to swap. A phase 2 doner (MY99-2001) would go in without any problems and if its an sti it would have slightly more agressive cams (there maybe more variations eg. type R) i think.

Anyway.....why do you (think you might) want to swap your engine??

Mike

 

as above,
Also a wrx engine will be more or less the same as yours anyway, the sti will however have stronger internals therefore a higher power output can be achieved without opening it up. Like above though you would need a ecu to unleash the extra from the sti engine or a remap

 

Thanks for all the info. I was thinking of changing my car, possibly getting a S204. I've got no problem getting one as I work for an import specialist in the Channel Islands. The only thing holding me back would be the cost. So I had an idea of swapping the engine, get a bit more power, well more power than what I'd get from exhaust/air filter upgrades.

The short engine sound like it could be a possibility. My Impreza is a June 99 model. Would a short STI engine from the same time just "drop in" without too much trouble? And if I wanted to change the gearbox can I use one from the same STI model I got the engine from?

What would the power differences be between a short engine replacement or a long engine one?

 

y not just swap an S204 motor into your current GC8 body? then have it reflash as well

 

Again, S204 a little expensive right now.

 

Yes the block and the gearbox are direct replacements. However, one problem is you will not know whta sort of condition the doner gear is in.

I wouldnt push the standard internals on a UK over 350/350, and the same goes for the gear box.....you do hear of some uk cars running happily above this and some that let go below these figures on standard internals (my box let go at 300lbft).

If putting a STi block and gear box I wouldn't know the 'SAFE LIMIT' but I would imagine it cannot be much above.....maybe 380/380??
Again im not sure what the box would take....but your ratios would be shorter and I think you might have to chage the diff.

With STi heads I think you will get earlier spool and more torque out of the setup.....but depending on what figures your after it might not be worth it.


I think the best way forward for you is to put up what your realistic target is in terms of power/torque and get some advice from there.
HTH
Mike