Putting a complete STI engine into a WRX, what is needed?
 

Having looked into the cost of re-building either of my engines I am looking to buy a complete STI engine that has had a recent rebuild to put into my WRX, I have found one at the right price but need to know if it will actually go in and run! The engine is out of a 95 JDM STI and my WRX is a 93/94 version 1 WRX. The only thing that isn't coming with the engine is the inlet manifold, will I be able to use mine or do I need to buy an STi one? also will I need an STI ECU and if so from what version?? Any knowledge on doing this swap would be greatly appreciated. Cheers

the engine will bolt straight in a run after you have swapped over the inlet the manifold, you will be fine running on the standard wrx ecu.

Thanks buddy thats good news, is there any power to be gained from using an STI inlet or is it the same as my WRX inlet but painted red? Same with the ECU, is there power to be gained from using an STI one?

pretty sure u need to be running the STi ecu and the loom to go with it. STI has different turbo, injectors, clocks etc so i cant possibly see how u can run it on a WRX ecu as theyre totally different engines.

i think you need to read up a little first, the early phase1 (version1 and2) wrx's and sti's were very similar engine wise and identical turbo and injectors, not a lot of difference in ecu, and clocks don't even matter, unless of course the sti clocks say sti, maybe that will stop them from working.

oh i see fair enough, id always just assumed that the differences between STI and WRX were fairly significant across the board even with regards to older models - my bad :)

sti will of had a z4 ecu and 440 injectors thats the only difference i think . the injectors will fit your fuel rails as will the ecu just plug n play :thumb: engine differences are internals higher lift cams and i think larger valves . some expert will be along soon enough to tell all i expect :thumb: ps both engines will of had td05 turbo the same , wiring loom the same unless ra with 5th injector . z4 ecu runs higher boost and slightly more ignition advance,

no they both had 380cc injectors, the wrx ran the z4, maybe the cams were different but the valves were the same size

Thanks for the advice guys, I think im gona go with the rebuilt STI engine and take it from there. Hopefully it will still run ok on my ECU and injectors, then i can start to look at tweaking bits. Out of interest does anyone have experience with Greedy electronic boost control?? my car currently has it and ive been told I should be able to up the boost to about 1.1 without any problems. Is this true? and if so any idea to power expectations? only mods are no cat full stainless and a decent panel filter plus the STI engine.

ok maybe ime wrong but y7 was ecu on my 93wrx now fitted with a z4
ebay 200622643958 z4
abay 190532218512 wrx classic

1.1bar = 15.84 psi both z4 and y7 ecu have lower fuel cuts than that , you will need a polar performance chip to do that as it raises the fuel cut to 1.15bar 16.6psi :thumb: