mondtster

Thanks this helps greatly. Im having troubles specifically sourcing the actual connector for the 2 pin avcs solenoid.

 

What timing belt kit did you use for this engine?

Did your engine not come with at least a partial wire harness you could salvage the connectors from?

The Legacy EJ25 timing belt kit will work for the 20X/Y. In fact, most parts will interchange. But you want to be careful and use a resource to confirm parts interchange before just assuming things will work. The older JDM motors are far worse than these for finding the right stuff.

Bump. Very good to hear the updated U20 heads allow for more timing compared to the z20. My tuner told me to not swap the z20-ej20x because it can't take any timing. I am considering the hassle of swapping in a U20-ej20x into an older gen 05 LGT. Asides swapping cam sensors (3 pin to 2 pin), do you see it requiring any additional wiring changes?

I can’t comment on the U20 heads but I can tell you that the Z20 and EJ20Y will not tolerate much timing with the fuel we have available in the US.

I’ve wondered how much of that was related to the heads rather than compression ratio though. The EJ20X and 20Y are engines that were definitely designed more with fuel efficiency in mind than overall power output. This can be seen in the stock calibration files and also just by the choice of higher compression ratio.

PCV systems on turbo cars are always a compromise to satisfy emissions constraints. If emissions is not a concern I’d remove the whole system and vent to atmosphere. Your choice whether or not to run it through an oil separator.

At a MINIMUM, you need to make sure the PCV valve will actually seal under boost. Otherwise you’re pressurizing the crankcase with boost pressure and making your problems worse.

The turbo Subaru PCV system is one of the worst I’ve seen, but oh so typical of a production turbo car.

I think in another thread someone got the USDM ECU working with the dual AVCS just by adding a few wires.

I'd love to know how, because far as I know the circuits aren't in the US ecu to do it. I'm thinking you're mistaken.

https://www.ebay.ca/itm/182990551646?ul_noapp=true

 

Subaru Legacy BP5 Outback 2.0L DOHC Turbo Manual ECU 8A 22611AH111 JDM EJ20Y ECU

 

I got confirmation from the seller that it would work for my EJ20x

 

Would I still need a tune for the different turbo?

 

I'm using a VF38

Is the car automatic or manual? The turbo used and the engine used (20x vs 20y) makes no difference.

Edit: I’ll mention it again. The hardware in the ECU is the same for both the M/T and A/T applications. The difference is in the software. Interpret that as you see fit. There will be problems using A/T software in an M/T application though.

Hi Bolts, That ECU is for a Non-Turbo engine. What you are looking for is a Denso 22611AK221. They show up on eBay every once and a while. the '04 models ('05 USDM equivalent) used the same ECU for the sedan and the wagon with the 5-speed trans.

Part of the part number is the software that is in the ECU. All you need is the right hardware and you can put the software you want to run in it.

I have a JDM ECU in a US car with Australian software. As I said before, these cars aren't terribly picky.

My first thought is that you have wiring or injector problems but you say you've checked those circuits. Assuming everything is actually good, you're back to the ECU.

You say you had the immobilizer removed, how did you do that? I assume you had someone modify the ECU software? The software would be a common denominator and something I'd be looking at.

I'm curious why you're putting this much time into using a stock ECU in a non-stock application? An aftermarket controller may be easier to work with.

Last but not least, hello from a fellow instrumentation guy!

Accessories and cluster might be different.. even within outbacks the year of the ecu has to match exactly ...unless I am mistaken?

They're not that picky.

Sorry, not that simple. '08 STi is a CANbus car. Without the matching BIU, ABS, HVAC units, dash, Si-Drive switch etc. the ECU will show a CANbus error and only run the car in limp mode. Also, the JDM motors from this era usually have different and incompatible cam position sensors.

I thought the later Legacys were CANbus too, no?

See if you can find the ADM FSM. ADM is the closest in spec to JDM and JDM models often don't have a FSM in English. Judging from the ROM IDs however it looks to me like the '08 JDM and USDM ECUs should be very similar. They're in the same series, which is not usually the case if the hardware architecture changed by much.

The '06 style JDM and ADM ECUs are all in the same family and software can be swapped from one to another as you please. I'm actually running an ADM MT based ROM in a JDM AT ECU with no issues whatsoever.

The newer cars may be different though. Starting out with the US STI ECU (the one with dual avcs) and ROM might be the easiest, if the pinouts match.

Oh. You don't need the wiring diagram for this, you need a section from the diagnostics section in the FSM that lists the ECM I/O

That's definitely the easiest way to do it, but if you wanted to you could do it via the diagram route too. They should have the pin locations on the individual schematics.

When I did mine I sat down with the I/O pages as you suggest. If I were the OP I'd take the 2006 JDM I/O page and compare it to the 2009 US page. If it looks like stuff pretty much lines up I'd consider taking a risk and pinning the cam sensors and control circuits in the cavities that the 2006 diagram shows.

Thanks mondtster! So basically you got a spool of something similar to this? Was there a reason you didn't go with the JDM engine harness?

https://www.wireandcableyourway.com/belden-9460-18-awg-1-pair-multi-conductor-single-pair-cable-tinned-copper-pe-insulation-pvc-jacket.html?gclid=CjwKEAiA2abEBRCdx7PqqunM1CYSJABf3qvau8TVVRhwa-GWPhNFfYnqmB6K_nMZe0GiMCoapnpnTxoCi1nw_wcB

 

Whenever I go for the engine, I plan on grabbing year appropriate ECU with connector plugs and a couple inches of harness to de and re pin. In reality I was hoping to get the complete engine with harness, and run an overlap harness like you mentioned from the main engine connector back through the firewall to the new ECU. Again, really need to dig into the pin out for the JDM and USDM to see if that's feasible without a lot of re pinning.

Don't waste your time with the JDM harness. It is set up for a RHD car and would be way more work than it is worth to mess with. Just use the US harness and add the necessary wires.

That wire looks like it would work.

Mondtster: Would you be willing to share where you got your shielded materials to make the additional part of the harness, and perhaps your assembly process?

Shielded twisted pair is readily available. What I used was made by Belden, I don't remember the part number. Most of the wiring doesn't even need to be shielded for this swap. I used the US harness and made an overlay harness with the additional wiring necessary to run the exhaust cams. To get the proper terminals to connect to the ECU I bought a set of ECU harness connectors from a junkyard and removed the terminals I needed. Then I inserted them into the connectors on my good harness and soldered my overlay harness onto those new terminals.

The JDM ecu's didn't even have an imobalizer function. So in theory you should be able to get it to start. BIU and cluster will probably pitch a fit though.

 

There is a separate UART bus going between the BIU and ECU for this functionality. Actually if you wanted to get clever, you could run both ECU's to trick the system into working. Just feed the old ECU the bare minimum for the imobalizer to work, JDM ECU does the rest.

The JDM ECUs do too have an immobilizer. I assure you it will not start unless the key codes in the ECU match the ones in the BIU. The VIN is not checked though...

You are correct that you have to have a ton of codes turned off and ready monitors forced on. I really don't wven know if the ej20x/y will even run on a usdm ecu if you keep dual avcs and intake manifold/sensors.

It will run on a US ECU ok. I ran one that way for a few thousand miles.

The codes for whatever you eliminated during the swap will need to be dealt with but if you put all the US parts on it I wouldn't expect any codes to pop up when running the US ECU. There will be no control for the exhaust cams with this approach however.

Does anyone have the wiring diagram for the ej20x or subaru with this motor in it?

If you look, it is easy to find the service manual for free. Long story short, to do this swap I would suggest sticking with the US wiring harness.

I think it's just stubborn and foolish to install a new factory shortblock without checking the ring gaps and resetting where necessary. It's usually only the top ring that's too tight.

That was kind of my point. There's nothing wrong with a stock shortblock, but make sure the clearances are set for the kind of use the engine will see.

Remember there are tolerance ranges on all parts. We have seen some factory motors with really scary gaps on the top rings, way smaller than the recommended gaps on aftermarket piston kits.

Which is why I've always questioned why people on this board seem to push buying a replacement shortblock from Subaru, rather than assembling an engine with tolerances more suited to a performance application in mind.

I suspect that Subaru knows that their ring gaps are tight. People need to remember that these engines and cars were designed with a purpose in mind, and that was to be a passenger car, not some high performance machine. Things like emissions and oil consumption are far more important to them than reaching high marks for durability (although too low will cause a loss of customers).

The area of the piston that breaks is where the high load bearing area is.

Can someone please confirm:

 

If you don't have the JDM ECU and for a 2008 LGT which is CANBUS, should be able to use the USDM ECU and not hook up the Exhaust AVCS, correct? Then just make sure to re-tune the engine.

You can, I drove my car for a couple of weeks on the US ECU while I was working the details out on the JDM ECU.

Have you looked into using an '08+ STI ECU? That might work in your application and give you dual AVCS.

If you have that old of a car I'd be inclined to use an aftermarket ECU.

I personally wouldn't have went with a Legacy motor for this but to each their own.

Im thinking of doing the ej20x swap in my legacy gt. It is half the price of the stock ej25 and comes with a twin scroll vf38 turbo. has anyone actually conpleted the swap, fully utilizing the quad avcs?

 

Thanks,

Gabriel

Yes, I have.

Ok what wiring and to what pins?

 

How do you "deal" with the immobilizer? Do I need a new key? New ignition?

I'm not going to do everything for you, the answers to the wiring needed are readily available via the diagrams in the factory service manuals. It should just require about 8 wires to be added. Two for each cam sensor and two for each valve.

The dealership might be able to program the immobilizer for you, but I don't know. I pulled the key codes from the EEPROM in my US ECU and copied them to the EEPROM in my JDM ECU. Doing it this way will allow all your currently existing keys to work but I can't add a key without a trip to the dealership.

Enlighten us then. I haven't seen a DIY on how it's done.

I told you what to do in my last post. Use the JDM ECU, the US wiring harness and add the wiring for the exhaust cam sensors and control valves. The biggest challenge is that the ECU is immobilized but that can be dealt with.

Found these:

 

http://forums.nasioc.com/forums/showthread.php?t=2623821

http://forums.nasioc.com/forums/showthread.php?t=1941416

Why would you eliminate dual avcs when it isn't hard to make it work?