Ej20G loom

[Guest]

So I have bought a EJ20 from 1st gen legacy I presume. It has no engine harness. I have been told the best idea would be to adapt a later model WRX loom and ECU as they have a better tune. This engine is going in a VW so it doesn't have to adapt to a car loom at all. Just need the engine to attach to harness and ECU.

Does anyone here know what WRX loom will fit OK for this engine. Because I have 2 bolt coil packs - will that also mean swapping to a later model hardware?

[ReubenH]

I'd recomend a Version 3 or 4 WRX loom. They run wasted spark, so you can chuck these useless old unreliable coils, and run a coil pack on the manifold instead.

The plugs and stuff are all the same, you'd just have to do some customising on the 20G (reversing the TPS wires, getting a new AFM to go with the wrx ECU etc.)

I'm not an expert on the conversion though, there's a few on here who've done it, i've just sat back and watched.

The benifit to the V3/4 loom. Is you can later plug and play with an STI ecu, yellow top injectors, and the bigger orange airflow meter, to get some free ponies out of the engine.

[Guest]

Interesting - thanks - will look into this.

Would this manifold be any different to mine? Or any benefit to fitting this instead of just the loom it comes with.

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Subaru/Engines/auction-320320140.htm

[ReubenH]

Nope, that'll be essentially the same. If you want a different manifold, look into the V3/4 ones, to match the loom. They have a different turbo intake and intercooler and stuff.

But, to be perfectly honest, if you have to ask these things, it's probably best you don't mess with it that much. It'd probably be easier to pick a version and run with it. Yes there's allot of stuff you can mix and match with, but the only way you can be sure it's going to work is to stick with your version. On that note, V1/2 WRX is more or less is the same as Gen 1 legacy, on the outside at least, so you can consider that 'sticking to a version'

[Guest]

Yes - sorry when I posted that link I am aware it is Version 1 - but wondering if this will adapt to my engine - ie. Will the sensors all be the same etc.

Does gen 1 have grey top injectors?

You are right - I'm a noob with subaru gear so best to stick with what is compatible with my engine.

[Guest]

I have found a 'either way solution'

Found a STi V3 manifold with all wiring, loom and ECU - also has a coil pack and leads.

Apart from the AFM is this just bolt on.. or do I need the yellow injectors?

option 2 - found the original manifold with harness, loom and ECU.

So can anyone weigh up pros and cons with option 1 - the STi conversion.

Also - if there is a link to someone who has converted to V3 - please paste on.

[Guest]

The crank and cam sensors will probably be differant too.

[Guest]

Can that be remedied with crank and cam sensors from a later model? Or is the early block different?

[Guest]

 fastie said:

Can that be remedied with crank and cam sensors from a later model? Or is the early block different?

Should just swap straight in.

[Guest]

Is this looking the business?

http://www.trademe.co.nz/Browse/Listing.aspx?id=321578624

[ReubenH]

That's version 2 mate, the guy doesn't know what he's talking about. This confusion often arises with the chassis code, as version 2 = GC8C. Not hard to see why they somethings think they have a V3. V3's are GC8D. (GC8A = "Version 0" that's why).

As for pro's and cons of the V3 or EJ20K intake setup and loom.

Pro's: No failure prone coil packs, yellow 440cc injectors, bigger dual entry intercooler, newer sensors, newer wiring? There's not allot to be honest, the main reason is to get the yellows in there while using a stock ECU. It's a null point if you go aftermarket management in future.

Cons: You gotta lean what is different, what's the same, and how to mix and match the two. While entirely possible and easy for someone who knows these engines in and out, it can be hard for someone unfamiliar, and allot of money can be lost in buying parts that don't work, or are said to be, for example, EJ20K parts, when they are infact what you already got - EJ20G parts.

~

I should probably make this clear.

Gen 1 legacy = BC5 (sedan), or BF5 (wagon), and they have EJ20G's. Legacy gear has additional wiring to run the water pump for the water to air intercooler, and the ECU has pins for this too.

Version 1 and 2 impreza = GC8B and GC8C (GF for wagon). These also have EJ20G's, there are some differences, these actually have the second generation of EJ20G, but the intake manifold, throttle body, turbo intake etc. is the same. The main difference is they have an air to air intercooler, and so no wiring for an intercooler water pump. Other wise though, more or less the same as the legacy EJ20G's.

Version 3 and 4 impreza = GC8D and GC8E. This is the EJ20K generation, with the 3 plug loom and yellow top injectors, bigger dual entry intercooler, etc. etc.

BUT HERE'S WHERE IT GETS TRICKY. The EJ20G was also available for this generation. This, the 3rd version of the G was found in foresters, auto's, and wrx wagons for version 3 and 4.. Manual WRX sedans, and all STi's got the EJ20K. The 3rd rev of the 20G however is more or less exactly the same on the outside as the 20K, so new loom, intake, intercooler, coil pack setup etc. The difference lies in the ECU, injectors, and engine internals. The 20G's still ran grey top 380cc injectors, but the loom and stuff is all 3-plug like the STi's EJ20K. So it's a bit of a mix'n'match.

They can be useful, if you want to get a 3-plug loom going, you can use one of those ECU's, and not have to worry bout the yellow injectors and orange AFM, good for a "i've swapped loom, but haven't got round to the STI bits yet" sort of deal. I've known quite a few people who've done this to iron out things before commiting to the STi/EJ20K parts upgrade.

For more on what the chassis codes mean, check here

http://www.clubsub.org.nz/forum/index.php/topic,11849.0.html

And a useful, and mostly accurate decoder can be found here

http://www.scoobyprojects.co.uk/technical/appliedmodel.shtml

[Guest]

Ok then - thanks for that reply - very good info - was hovering over the buy now.

I've sourced everything standard for this engine and really just want it plug n play - as the power will be plenty with only 850kg all up.

Perhaps mods in the future once I have my head around what is what and where

[ReubenH]

If you have all the 20G stuff there, just run with it, mixing and matching parts is probably inappropriate at this time. On further thought, i really would suggest to just keep in simple and stick to a single version at this stage. And you're right, maybe a 3-plug swap is something you can do in future.