Saab 92-X convert to WRX???

My friends have a SAAB 92-X, LINEAR (non-turbo) for sale. It's in great condition. Automatic transmission. This car is, near as I can tell, actually a Subaru Impreza RS in wagon form--except that it has a better suspension than an RS, and has heated seats. It seems to be exactly the same car as the AERO version, and the AERO version is a WRX.

Question: If I pull the 2.5 RS engine, and replace it with a 2.0 EJ20 WRX engine, do I have to replace any of the wiring? The ECU? The transmission, box, instruments, gear shift, everything is Subaru.

If I do have to replace or add wiring, what do I have to replace or add? I want to keep the automatic transmission. It's a Subaru 4EAT.

Lots of people have added a 2.0 WRX engine to an RS, but near as I know no one has done it with an automatic transmission.

sounds like a sweet ride. post up some pics.

You'll have to make a completely new wiring harness by merging the 9-2x harness and the WRX harness, if it's even possible.

I think the harness for the automatic might be the same for both the Linear and the Aero. Transmission is the same, shifter is the same, gauges are the same. The only difference I can see is in the engine compartment.

The RS is different in many ways from the WRX. But I don't think there is that much difference in the two 92-X models. Both are wagons. Same brakes, same suspension, wheels, etc. SAAB picked and chose the parts they wanted: the front end, for example, has some STi parts. The rear hatch is from a Legacy and not an Impreza, and so on. The car drives much better than a stock WRX, even though it is not the turbo.

All parts, other than headlights and hood and front bumper, are Subaru parts. I'm hoping that in order to be as cost effective as possible, SAAB simply used the same wiring harness for both versions.

They may have the same parts, but when you're going from N/A to forced induction there are tons of differences.

Yeah. I was just hoping against hope that maybe they used the same wiring harness and left a lot of it blank in the non-turbo. On the other hand, how hard can it be to replace a wiring harness? LOL. Don't answer that.