2005 Subaru Legacy GT with EJ20X

[danedoremus]

Hello, I have done a lot of reading online over all and I wanted to make my own post to see if I can find the information I’m looking for.

 

I’m swapping a EJ20X in to my 2005 Subaru Legacy GT

 

Can I swap my EJ255 exhaust cams and gears in to my EJ20X engine ?

[m sprank]

Welcome to the forum. I can not fathom why anyone would want to swap to an EJ20X. All I ever saw were problems. But, to each his own.

 

 

 

You have lots to research. Google is your friend:

https://www.google.com/search?client=firefox-b-1-d&q=EJ255+exhaust+cams+and+gears+in+to+my+EJ20X+engine

[Tuning Alliance]

Hello, I have done a lot of reading online over all and I wanted to make my own post to see if I can find the information I’m looking for.

 

I’m swapping a EJ20X in to my 2005 Subaru Legacy GT

 

Can I swap my EJ255 exhaust cams and gears in to my EJ20X engine ?

 

I have swapped plenty of these. Lot of bad info out there.

 

There is no reason to swap any cams or gears. You can use the long block just the way it is with the USDM harness. Thus there is no connectors for the exhaust avcs and they simply run in there default position.

 

This swap is popular because 20x is dirt ass cheap and holds its own against ej25.

[danedoremus]

Welcome to the forum. I can not fathom why anyone would want to swap to an EJ20X. All I ever saw were problems. But, to each his own.

 

 

 

You have lots to research. Google is your friend:

https://www.google.com/search?client=firefox-b-1-d&q=EJ255+exhaust+cams+and+gears+in+to+my+EJ20X+engine

 

The EJ20X engine is great IF you do it correctly. But it’s not cheaper then doing a 2.5 short block and sending the heads out to have cleaned up and putting a 2.5 back in the car. There is a lot more to swapping a EJ20X then people tell online. They think you can put the engine in the car and run it on a usdm ecu and leave the dual AVCS unplugged. That is incorrect and makes them default to Advance mode plus it makes the cylinder pressure higher and the engine is already 9:5:1.

 

I have already been on google and I have done this swap once in my 05 legacy but I got a bad engine and has took a dump. I have also seen people say that a lot to how they buy these engines and get them with low compression.

 

There is iwire I can buy to hook the dual AVCS up or I can swap my EJ255 cams over to the EJ20X with gears.

 

So I have seen you comment on other post about the EJ20X being bad and not a great idea but you never say why ? So why is it bad?

[Max Capacity]

Just saying, browse through my "click here" link.

 

140,000 trouble free miles in the ej257 shortblock. Both members above have been a big part of that.

 

Its so easy to do it right the first time.

[dgoodhue]

You need the JDM ej20x ECM to have the functional dual avcs. If you live in a state where they hook up your computer up for emission you won’t be able to pass with the ej20x ecm.

 

I reread your post. I think most people use the ej20x harness, for wiring up the dual avcs.

Edited August 21, 2020 by dgoodhue

[m sprank]

So I have seen you comment on other post about the EJ20X being bad and not a great idea but you never say why ? So why is it bad?

 

 

Because in my experience it is cheaper and easier to get a reliable result from the stock EJ255. Not to mention the emissions issues. In Cali (where my shop was located) the car can not be (easily) legally registered with a EJ20X swap.

[Tuning Alliance]

The EJ20X engine is great IF you do it correctly. But it’s not cheaper then doing a 2.5 short block and sending the heads out to have cleaned up and putting a 2.5 back in the car. There is a lot more to swapping a EJ20X then people tell online. They think you can put the engine in the car and run it on a usdm ecu and leave the dual AVCS unplugged. That is incorrect and makes them default to Advance mode plus it makes the cylinder pressure higher and the engine is already 9:5:1.

 

I have already been on google and I have done this swap once in my 05 legacy but I got a bad engine and has took a dump. I have also seen people say that a lot to how they buy these engines and get them with low compression.

 

There is iwire I can buy to hook the dual AVCS up or I can swap my EJ255 cams over to the EJ20X with gears.

 

So I have seen you comment on other post about the EJ20X being bad and not a great idea but you never say why ? So why is it bad?

 

Well then I guess i did mine incorrectly to your standards. As mine is a usdm harness and ecu with no exhaust cam control. I'm seeing much better mpg then a ej255 due to the higher CR and lower engine volume. Power, and drivability are no different than a ej255 $735 picked up with a 30 day warranty hard to beat.

 

I love the ej20x its like a baby fa20 to me. Flex fuel or some methanol and it'll hurt some feels.

-9.5:1 CR

-7300/7500 rev limit

Edited August 27, 2020 by Tuning Alliance

[m sprank]

It would be a cheap and fairly easy swap on a beater here in WV. But I still like the EJ255/57 enough not to swap unless I had to.

 

But in Cali... for a legal engine swap the engine used must be newer than the engine removed and swapping the ECU is not legal. Tuning is not legal either. The pump gas is 91 piss waterd down with 15% sugar cane ethanol. 9.5:1 is asking for knock 350 days a year in So Cal. I drove a highly modified, but stock tune 93 Forester XS with 10.5:1 compression and had to mix the 91 with 15% e85 to stop the knock.