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EJ20X swap AVCS delete


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Just got my EJ20X in, going to start my swap tomorrow. Car is an 07, so unfortunately I can't swap the JDM ECU. So I need to delete exhaust AVCS to keep the US ECU... I can tap and plug the oil ports, but what do I need to do about the timing retard? Do I just turn the gear 2 teeth CCW? I read that on a how-to somewhere, but I think it was on a 205, not 20x, so not sure if it is the same. Also, will my old EJ255's exhaust cam gears work, or do I need to source a set off a different engine? Thanks!
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Just got my EJ20X in, going to start my swap tomorrow. Car is an 07, so unfortunately I can't swap the JDM ECU. So I need to delete exhaust AVCS to keep the US ECU... I can tap and plug the oil ports, but what do I need to do about the timing retard? Do I just turn the gear 2 teeth CCW? I read that on a how-to somewhere, but I think it was on a 205, not 20x, so not sure if it is the same. Also, will my old EJ255's exhaust cam gears work, or do I need to source a set off a different engine? Thanks!
You might find good information here.

 

http://legacygt.com/forums/showthread.php?t=260952

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Thanks Rhino. I have actually read through that thread. He is trying to use the JDM ECU and keep AVCS, which would be awesome, but it looks like he is having hell with it. Seems to be a much bigger deal on the 07+ ECUs.

 

I want to get up and running quickly, so I plan to delete the AVCS. Just want to make sure I get the timing correct.

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Actually, it looks like he got things ironed out! I read it a few days ago and it looked like he was stuck with some problems. This may be an option again after all, thanks Rhino!!

 

That being said, if anyone has a definitive answer on clocking the exhaust gear, I'd like to hear it so I can keep both options.

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  • 5 months later...

Hey @%1;,

 

Did you ever get this sorted?

 

I found this, which seems pretty definitive on the AVCS delete.

 

I have a 2005 Outback which I believe may have a mechanical problem, and I'm looking to swap in an EJ20x, and keep my ECU. If you completed this swap on a similar car, I'd love to know how your experience went.

 

Does the intake AVCS still work as expected?

 

Did you have trouble retuning for the higher (9.5:1) compression?

 

Did you swap over all of your intake/turbo parts?

 

Did you keep your stock turbo or use the twinscroll that came with the EJ20x?

 

Thanks!

Edited by rgeyer
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@rgeyer, I'm clearly not the OP but I put EJ20X into my Outback over the spring, here's what I did:

 

You don't need to touch exhaust side AVCS, just leave it unplugged and it defaults to advanced mode. Sure you may lose a little power but it's plenty fast defaulted to advanced mode

 

Intake AVCS will remain functional

 

I downloaded a rom from an Australian LGT running an EJ20X and I copied all the tables and pasted them to my USDM rom, otherwise yes, you will spark knock like crazy.

 

I used my USDM manifold and wire harness

 

I used the twin scroll (it's freaking AWESOME!)

Edited by g0lds
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@rgeyer, I'm clearly not the OP but I put EJ20X into my Outback over the spring, here's what I did:

 

You don't need to touch exhaust side AVCS, just leave it unplugged and it defaults to advanced mode. Sure you may lose a little power but it's plenty fast defaulted to advanced mode

 

Intake AVCS will remain functionality

 

I downloaded a rom from an Australian LGT running an EJ20X and I copied all the tables and pasted them to my USDM rom, otherwise yes, you will spark knock like crazy.

 

I used my USDM manifold and wire harness

 

I used the twin scroll (it's freaking AWESOME!)

 

This is great! Thanks for the details.

 

I've read several other reports that suggest just leaving the exhaust AVCS unplugged, somehow that feels... Wrong.. But it certainly is the simpler solution.

 

I haven't quite finished diagnosing my car, but I've been chasing a knock correction with no apparent AFR issues for months now, so I think I've got a mechanical issue/noise. Going to check my compression and a few other variables before I give up and throw the EJ20X in there.

 

Thanks again!

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OP here.

 

Swap is conplete-ish and runs well.

 

Intake ACVS is fully functional on USDM ECU.

 

Tuning Alliance is doing my tuning, and we are still in the process. About 7 or 8 maps in. Car starts, idles, normal drives perfect as can be. 1 and 2 gear pull hard. 3rd gear WOT it seems to struggle building speed. TA recommended I upgraded the fuel pump which I just did. Waiting on next map to test it.

 

Intake, exhaust, wiring and ECU are the same USDM equipment that was always on the car. Turbo was upgraded to VF52. Thought about using the twin scroll, but my EJ20x came with a blown turbo.

 

 

 

As for the exhaust AVCS, I am running untouched and unplugged like most other guys. It's not the right way to do it, but it works for the time being. Deletion route is still murky and unclear. I did see that post you linked when I was searching, but I am not 100% sure that it translates to this application. I also don't have the gauge he used to clock the gears. In my first post, I mention clocking the gear a couple teeth CCW because that's how that post starts before it gets real technical/precise. In theory this would get you really close to where you want to be, but I just couldn't confirm it and didn't want to risk valve damage.

 

The best way to do it is run the necessary wiring and use a JDM ECU and actually use the exhaust AVCS. There is a post about that linked in here somewhere. The guy got it working, but it was a hell of a time getting there and he lost ABS and traction control in the process. If he ever finishs blazing that trail 100%, I may copy him, but in the meantime just running unplugged does the job.

 

Good luck! Happy to answer any other questions.

Edited by Crankwalk
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OP here.

 

Swap is conplete-ish and runs well.

 

Excellent! Glad to hear that.

 

Intake, exhaust, wiring and ECU are the same USDM equipment that was always on the car. Turbo was upgraded to VF52. Thought about using the twin scroll, but my EJ20x came with a blown turbo.

 

From what I've been reading, the biggest issue here is getting a downpipe that'll work. There are aftermarket "cheap" options here, but I'm in CA and want to try to keep it at least stock looking.

 

So, glad to hear you're using all the USDM stuff. I've also decided I want to run a VF52 on my setup whether I find and fix the problem with my EJ255, or if I get an EJ20X.

 

How's that "big" turbo working on the 2.0 for you? Sounds like it's good, and your tuner is happy with it?

 

As for the exhaust AVCS, I am running untouched and unplugged like most other guys. It's not the right way to do it, but it works for the time being. Deletion route is still murky and unclear. I did see that post you linked when I was searching, but I am not 100% sure that it translates to this application. I also don't have the gauge he used to clock the gears. In my first post, I mention clocking the gear a couple teeth CCW because that's how that post starts before it gets real technical/precise. In theory this would get you really close to where you want to be, but I just couldn't confirm it and didn't want to risk valve damage.

 

The best way to do it is run the necessary wiring and use a JDM ECU and actually use the exhaust AVCS. There is a post about that linked in here somewhere. The guy got it working, but it was a hell of a time getting there and he lost ABS and traction control in the process. If he ever finishs blazing that trail 100%, I may copy him, but in the meantime just running unplugged does the job.

 

Good luck! Happy to answer any other questions.

 

Yeah, this seems to be the main sticking point for this swap for me. I found a thread here of a guy who basically did exactly the same swap I did, but got a newer model EJ20Y, with an air pump. He had a few small wiring issues, and had to swap some sensors.

 

From what I've been able to figure out, if I can find the pre-facelift EJ20X, and a JDM ECU from a BP5 (already ordered one on eBay) I should just have to add 6 wires to my harness, and get the dealer to program the new ECU for my immobilizer.

 

*should* be easy.

 

Bear in mind, I'm running a 2005 Outback, so pre CAN-BUS. Meaning that I shouldn't have a lot of issues integrating with the other body/ABS/etc computers, or so I hope. :)

 

Thanks for the answers. I'm *still* trying to track down the actual issue with my car, but with 160k miles on it, some questionable history before I got it, and an unknown amount of time running with a torn inlet hose, I'm thinking that a fresh longblock is probably in order at some point anyhow!

 

This is my troubleshooting thread, which is long, and brings me from general Subie n00b, to having a pretty decent understanding of these things.

 

When/if I start a swap, I'll fire up a thread over there for it.

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Leak down test. Leak down test. Leak down test. It will tell you what you need to know!

 

You being an 05, pre-canbus, makes going the quad avcs route a little simpler. Us canbus guys have a much finickier ECU. As you said, you want a prefacelift EJ20x/y before the air pump. I'd have been better off with the newer air pump model, but the price difference was ridiculous.

 

I believe it is more than 6 wires, think it is 10 or 12 wires. 3 for each avcs actuator and 2 or 3 for each cam position sensor. But still should be fairly simple to wire up.

 

VF52 works great with the higher comp EJ20x! Tuner was happy with it and even cranked the boost up on it. No problems there. I thought about going twin scroll, but finding a downpipe is a pain, severely limits your upgrade path, and the VF38 is horribly unreliable (from what I have read, and semi-confirmed by mine coming in totally shot).

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Leak down test. Leak down test. Leak down test. It will tell you what you need to know!

 

My tester arrived yesterday. I'm out traveling for business until the weekend, by then I should know more. I almost sorta hope that I find that one or more cylinders are quite leaky, then I can stop hunting for the problem. :/

 

 

I believe it is more than 6 wires, think it is 10 or 12 wires. 3 for each avcs actuator and 2 or 3 for each cam position sensor. But still should be fairly simple to wire up.

 

Right, I forgot about the cam sensors. 10 wires, but still no big deal.

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Leak down test. Leak down test. Leak down test. It will tell you what you need to know!

 

No leakdown necessary. Cylinder 4 shows 65 and 70 PSI on subsequent tests. The others are 125-130PSI.

 

My longblock is tired, time to move on.

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  • 6 months later...

Sorry to bring this thread from the dead, but I have an ej20x head and block with the unconnected passenger side AVCS (exhaust one?) and I have an 05 LGT. I wanted to know if I get a JDM ECU-- will my 5EAT shift better? Some people say with the EJ20X I can get a tune to fix the transmission hard shifting?

 

Thank you much! Hope your car is doing well.

Edited by Carmania24
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Sorry to bring this thread from the dead, but I have an ej20x head and block with the unconnected passenger side AVCS (exhaust one?) and I have an 05 LGT. I wanted to know if I get a JDM ECU-- will my 5EAT shift better? Some people say with the EJ20X I can get a tune to fix the transmission hard shifting?

 

If you are trying to pass CA emissions, a JDM ECU will never pass. It doesn't have the correct protocol to connect to the emissions equipment.

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Sorry to bring this thread from the dead, but I have an ej20x head and block with the unconnected passenger side AVCS (exhaust one?) and I have an 05 LGT. I wanted to know if I get a JDM ECU-- will my 5EAT shift better? Some people say with the EJ20X I can get a tune to fix the transmission hard shifting?

 

Thank you much! Hope your car is doing well.

 

No, I don't see how that will help shifting at all. My car is running on USDM ECU and shifts just fine. I imagine you have some other issue there.

 

Also, you mention the passenger side AVCS, but you have the exhaust disconnected on both sides right? I imagine so if you are using the USDM wiring harness, but just checking. Something funky would be going on if one side is hooked up differently.

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