Hi, I have a V5 Type-R currently without the oem engine. I also have a complete Legacy EJ255 with broken ringlands, and a bugeye STI EJ207 longblock in pieces.

I would like to use the 2.0 litre configuration rather than 2.5 thinking that a revhappy engine suits the OEM gearratios better. And I would like to get use of the AVCS function.
This is one of many projects so I would like to keep this cost effective and smart. I´m prepaired ,and I assume forced, to use a standalone ECU to make this work, but my mind is a bit scattered and I know many of you know just which path is the best.

Would it work to assemble the EJ20 longblock, use the external parts of the EJ255 and PNP a standalone ECU to the OEM harness? I assume the AVCS function (and maybe something more?) demands some additions to the engine harness in the car, is it possible, or is it smarter to ditch the stock harness completely and use an aftermarket harness between ECU and engine?

Or would a later gen STI ECU with ECUTEK be possible to adapt to the OEM engine harness?

Thanks for a great forum!

//N

 

Welcome -- would like to offer advice , but I don't have the knowledge...

 

Tjena Nicklas,

With a longblock EJ207 I assume you mean complete with the AVCS heads? To use a pnp V5 aftermarket ecu you would need the V5 engine loom with the V5 intake manifold, throttle body and idle control valve. To use that intake manifold with AVCS heads you need to use 20mm intake manifold spacers otherwise the fuel rails won't clear the AVCS oil control valves. It's possible to use the newage intake manifold also but would need some wiring changes for the throttle body and the different type of idle control valve.

I use a Link G4+ ecu but the wiring has to be slightly modified when using that ECU, not sure if that's the case with the new Link G4X but I suspect so. And you'll need a loom for the AVCS of course.

"The 2 extra cam sensors need to be wired to DI 1 & 2, these inputs were originally used for the start signal and the power steer signal. These can be moved to DI 7&8 on the expansion connector instead to free up DI1&2. You dont really even need the start signal.
The AVCS solenoids need to be wired to Aux 1 & 2 which were originally used for fuel pump and wastegate valve. Similarly these wires can be moved to Ign 7&8 on the same expansion connector to free those pins up. Aux 3 may also be another option if air conditioning is not needed."

Alcatek with the AVCS extension board is fully pnp but good luck finding anyone in Sweden to map it. With that in mind I would recommend either the Link G4+ or simply wire in a Maxxecu which is the most supported here. Syvecs is also an alternative but not known to many mappers here.

I guess it all depends on which parts you have available. If you would wire in a Maxxecu it wouldn't matter that much as long as the intake manifold fit the heads.

 

if you want another cost effective option you can use oem gdb sti ecu

i'm converting my car (my99 impreza classic)

i'll use oem jdm gdb sti ecu because i want to use carberry rom

but you need, gdb throttle body, iacv, ignition coils, 2l non avcs cam and crank sprockets(if you don't have avcs). i think you can find complete gdb intake manifold with throttle body etc.

also you need new age ecu sockets


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