EJ20 turbo heads rods and pistons in sock ej20 shortblock?

[Mati_Suba89]

Greetings everyone!

I'm on the verge of a legacy BD turbo build and have loads of concerns! (i promise i will make a build complete build thread when i get started).

The car is a stock 95 2.0 non turbo subaru legacy GL sedan with 165k completely stock.

My initial project was to find a wrecked GC8 impreza (here called impreza gt with a ej20g turbo engine) but had no luck so i'm analyzing the possibility to tear appart my ej20 and stuff these inside it:



They are stock rods and pistons from a 99 wrx gc8.

Im not quite sure weather those rods are compatible with my crank shaft, i don't even know if my legacy's stock rods will do well with the turbo conversion done.

I also got my hands on a pair of DOHC heads from the same ej20 tubro and am not sure if those would be better than my stock SOHC ones or not.

In other words, i feel a bit lost in all this and need some advice to get my head straight!

[mike-tracy]

Hi Mati, welcome to the forum.

These rods and pistons will fit your engine and crank. The wrx dohc heads will fit also, you simply use the head gaskets designed for the wrx engine. The wrx heads have cams specifically designed for turbo and breath quite a bit better than SOHC in that capacity. Not to mention, they already have the turbo's oil and coolant ports, so you won't have to drill and tap. Question though - even though the parts fit, how will you control the engine?

[Mati_Suba89]

Hi Mati, welcome to the forum.

These rods and pistons will fit your engine and crank. The wrx dohc heads will fit also, you simply use the head gaskets designed for the wrx engine. The wrx heads have cams specifically designed for turbo and breath quite a bit better than SOHC in that capacity. Not to mention, they already have the turbo's oil and coolant ports, so you won't have to drill and tap. Question though - even though the parts fit, how will you control the engine?

Hi Mike, thanks for the welcome and response! i'm glad to have joined.

That is a good question. As far as my reaserch findings go, i have two possible options here. Either piggiback EMS and the stock legacy ECU or an ECU from a turbo impreza with it's equivalent engine wiring harness spliced into the leggy's harness. Firs option seems less work to be done but the seccond might have better results. Problem is getting the proper parts. I live in Argentina and customs don't allow us to import used auto parts so ebay unfortunately is not an option . bummer

[Legacy777]

I would agree I think the turbo impreza ECU & appropriate sensors would probably be a better option, but the piggy back would likely be an simpler solution.

[Mati_Suba89]

I feel quite sceptical on the whole ecu/ems and wiring issue. I have done a bit of reading and browed all the videos i could find and still feel the most logical and "failproof" solution is using an impreza's ecu. I'm affraid of facing a harness splice and messing things up! Maybe i should open a thread in the electrical section.

I got word today that the heads i purchased are actually STI's (still gc8 though) so i'm quite happy! Also stopped by a friend's official subaru service garage and confirmed that the heads and pistons should definately fit my block. He also said that i'm totally nuts for wanting to do this

[Legacy777]

Yeah if you have any electrical/ECU specific questions starting a thread in the electrical forum would be good.