Difference between wrx and sti engine
 

Could anybody tell me the difference between a wrx engine and sti engine on a MY95 classic? I have a STi type RA and am considering putting in a wrx ra engine due to bottom end failure, but not sure how much of a difference there is between them? Any help would be appreciated!

a wrx ra is an sti there for, it is an sti engine . only put in the engine that goes with the car . an sti engine is very different to a standard wrx engine . you must fit a version 2 sti ra engine closed deck block etc . otherwise it wont really be an sti ra anymore just the body and running gear of one .

the difference between the 2 engines is forged internals, and I believe the heads are slightly different. There are sti engines with closed deck blocks but there are also plenty with open deck blocks as well. You dont need the same version engine to go in the car as they are generally a straight swap as long as it is from the same phase car, however as said above dont put a wrx engine into an sti unless the ecu was swapped to a wrx ecu

No it's not, you can get WRX RA's and WRX STI RA's, they have different engines and the WRX RA tend to have no rear spoiler.

Holdup, you say an STI engine is very different from a standard wrx engine, but in the case of a wrx ra engine is there still a lot of difference? Also, I have a uni chip piggy back ecu so I would assume that if I have this it can be mapped to suit a wrx ra engine?

that is a good question, what is the difference between a normal wrx engine and a wrx type ra engine?

As far as i aware nothing (could be wrong though), the difference with the RA isn't the engine, it's a lightweight version of WRX with a short ratio gear box.

agree with above it is a short ratio gearbox:thumb:

wasnt aware of a wrx ra as well as a wrx sti ra , if this is the case it still doesnt change the fact that an sti engine is different , as said above it has stronger internals and as with the sti ra , closed deck block . if i was putting a new engine in to my sti ra it certainly wouldnt be a non sti engine , To sum it all up the standard wrx engine is inferior to an sti engine and would seem a bit of a shame to put a non sti engine in to an sti .