jdm ej20x motor for '05 Outback XT. Need some help tuning a jdm ECU..

[m sprank]

You need to speak with a tuner first snd make sure they will still tune the set up as federal law has dramatically changed in the past few years.  The tuning options will guide your decisions.  

Not even sure Cobb still offers support, so check before buying an accessport.

The cams retard with oil pressure and advance without.  It is not lubrication, but operation. You lose operation of the avcs, not lubrication of the cams and head.

You should be able to use your manifold set up, etc. It has been 8 years? since my last swap, but I recall using the LGT manifold/intercoolet/etc.

Edited February 22, 2023 by m sprank

[RumblyXT]

I have decided to keep the usdm ECU to avoid the jdm ej20x dual AVCS, jdm ECU programing/tuning and longer wires to exhaust cams issues..

I will try swapping the exhaust ej255 non AVCS cams/gears for the ej20x  exhaust cams and keep everything else usdm/possibly stock. So the only thing I’m using from the jdm motor is the long block minus the exhaust cams/AVCS Gears.

It should work in theory, since all ej camshafts have all the same fitment (according to Flatirons Tunning). With this setup, I won’t have deal with the jdm dual AVCS/timing headache. But I think I would have to keep the jdm exhaust solenoid since they provide oil to the cams. That’s why I was asking about oil starvation on the exhaust cams if I go with the usdm ej255 cams.

Hope I didn’t confuse you. What do you think?

Edited February 22, 2023 by RumblyXT

[m sprank]

The oil control valve does not supply oil for lubrication.  Its sole purpose is to regulate oil pressure which controls the avcs. Once you disconnect oil pressure the avcs will max out advancement and stay.  Why swap cams? Then you have to either buy a bucket set or grind valves to set lash. 

If you just want a engine "swap" you are now overthinking it. You need to make sure tuners will still handle a standard ej20x swap.

Lots of threads across multiple forums detailing the standard swap ditching the exhaust avcs. 

[RumblyXT]

Oh crap.. you’re right.. I forgot about the valves and the buckets they’re each worn out, paired to each cam..

So what then? Swap the ej255 non AVCS exhaust gears to the ej20 exhaust cams once these are capped?

Sighs..

Edited February 22, 2023 by RumblyXT

[m sprank]

The oil control valves are external on the head.  You can simply use a bolt to "cap" by replacing the banjo bolt.  You do not need to swap gears.  They will work all the same. 

[RumblyXT]

I see.. so the oil control valves (solenoids) control the AVCS gears through oil pressure in them interpreted by the ECU. But the cams will get their lubrication through the engine oil splashing around inside the heads.

I was confused because I had seen oil ports, holes on the front of the ej20x exhaust camshafts where the AVCS gears are mounted on..

Edited February 23, 2023 by RumblyXT

[m sprank]

On second thought, as its been a good 8 years.  As your wiring harness does not have the plugs for the cam sensors or oil control valves, dont block off the oil.  Just leave the solenoids and sensors unplugged.  This way you guarantee the front cam journals stay lubricated.

 

IIrc you will need to swap over the intake/intake manifold/fuel lines/fuel injectors/AVCS solenoids/turbo/exhaust manifolds/crank pulley/power steering pump/A/C compressor.

You might be able to carefully bend the JDM turbo oil line to hook up to the USDM turbo.

[RumblyXT]

Yes to avoid issues I’m going to keep the usdm ECU and swap over everything North and South of the ej20x long block.

I’ll find a way to have the ej20x exhaust cams/gears as non AVCS, that way the usdm ECU should function and control them as if it was an ej255 motor.

Not sure if I might also need a usdm water pump and delete the oil cooler from my ej255 too for this swap.
 

Edited February 23, 2023 by RumblyXT

[m sprank]

1 hour ago, RumblyXT said:

 

I’ll find a way to have the ej20x exhaust cams/gears as non AVCS, that way the usdm ECU should function and control them as if it was an ej255 motor.

 

Just leave the solenoids and sensors unplugged.  ECM does not know they were AVCS, without the solenoids and sensors they are no longer AVCS, just like USDM.

[RumblyXT]

6 hours ago, m sprank said:

As your wiring harness does not have the plugs for the cam sensors or oil control valves, don't block off the oil. Just leave the solenoids and sensors unplugged.  This way you guarantee the front cam journals stay lubricated.

^^I think this is the key to this swap.

Check out this reddit reference guide, this user plugged the 20x exhaust camshafts..

I wonder why he had to plug the 20x camshaft oil feed holes though, maybe because he didn't swap the 20x exhaust AVCS gears for the the ej255 non AVCS one..

I guess the main question is: would it be ok to put together 20x exhaust cams with ej255 non AVCS exhaust gears?

Thank you m sprank.

Edited February 23, 2023 by RumblyXT

[m sprank]

So many ways...  You can do that.  You can plug the oil ports and use your EJ255 exhaust gears.  You can not plug the ports at all and just leave it like I said prior.  The differences are in how power and spool are delivered.  The exhaust cams not being controlled and defaulting in timing combined with the absence of proper valve overlap timing can kill the top end. 

Want the most power?  Want the most top end?  Want as simple a drop in as possible (use your yellow injectors as they are larger than the blue JDM).  Originally you wanted to use the quad AVCS, which was do-able back in 2013/14 or so.  What is the final plan?  Easy, or the most possible out of the set up using just the intake AVCS?  What turbo are you going to be running?

Edited February 24, 2023 by m sprank

[RumblyXT]

I just want to get the car/motor running again, in the most reliable and economic way possible. I'm not interested in power or any aftermarket parts. In fact, I wish I could put the car totally back to stock. I'm preparing it for my father in law, this is why I want to make sure it's done correctly.

Making the 20x a single AVCS seems to be the best option for me, since I could keep using the usdm ECU, functioning like an ej255. I will also be using the turbo from the ej255. I appreciate the input on the injectors, I wasn't sure which to use. I'm not sure however if I could swap over to the 20x, the oil cooler and water pump from the ej255.

 

 

Edited February 25, 2023 by RumblyXT

[pleiadesfella]

while I was looking into this swap, I found this video to be very helpful for wrapping my head around the easiest way to go about it. I hope it's helpful for you as well, tho you may have already seen it by now lol.

 

[RumblyXT]

Yes, I saw it. Jesse is super cool and clear up a lot of questions. That video is great. But after all my research, the only think I disagree with that video is leaving AVCS gears on the exhaust side of the motor.

Thank you

Edited February 27, 2023 by RumblyXT

[m sprank]

Like I said, more than one way.  Someone will say "this is the right way" and another will not agree.  It boils down to how much work do you want to do and how much of the  engines design are you wanting to keep. 

If I decided to do an EJ20x swap to save money over rebuilding an EJ255, wanted a higher revving engine with possibly better ringland and headgasket reliability, but was not willing to perform the full dual AVCS swap I would drill and tap the cams to seal the oil ports and use my EJ255 gears.  I would use as much of the USDM intake manifold, tgv, fuel lines, rails, injector, accessories, etc as possible and would not be looking to use any twin scroll parts that might come with the engine. 

[RumblyXT]

This video answered mostly everything.. it wasn’t intended for an ej20x swap, but goes in depth on swapping a dual AVCS STi motor into a single AVCS WRX, and it’s pretty much in the same order of things on what I’m trying to achieve..

 

[m sprank]

The "what we did" from 02-06.  I always really liked taking the 2.0 and "stroking" it to 2.2 (2.17 technically) over the swap.