Ej25 non turbo to ej20

[ZuluKing]

I bought an ej20 turbo with ecu and harness, to swap into my ej25 non turbo, and was wondering what else I would need, and what I would need to get a full function engine, if maybe there’s a post for step-by-step how to swap ej25 to ej20

[KZJonny]

Dude. This is the second time you’ve come asking about how to install the wrong engine in your car.

Is there some good reason you don’t just get the correct year range EJ253 and replace the one you have?

 

There isn’t a step by step walkthrough to put a JDM EJ20 into a base, non-turbo car because it’s a bad idea, so nobody who knows what they’re doing does it.

If you want a turbo Subaru, it’s cheaper to just buy one than do what you’re doing. If you just want to fix your car then get a used EJ253 and swap that. If you want to be the first on here to so do, take lots of photos for everyone else to learn from.

 

It’s going to take some skills to get all the wiring mates up and a new exhaust fabricated, bigger brakes to match the horsepower, etc…. Not to mention the transmission if you don’t have a manual. There are LGT’s in good shape around here selling for less than the total cost to do what your talking about, and you won’t even end up with a real GT, with no resale value.

Think very carefully about this before it’s too late to return that engine.

 

[seanyb505]

Yeah... people struggle to get the ej20 running right in an turbo car. 

These people asking the turbo into non turbo and manual into auto cars... that's the shell game. Buy an entire donor vehicle and swap everything into your shell. Or drive the donor car. 

A few have stuck the ej20 into north America cars, but that ecu already kinda expects boost. The NA car doesn't. Best to buy either a turbo car, or find a totalled one with a bad fender bender. Then swap absolutely every piece of body wiring into your car. You'll also need the donor keys. And the previous owner's kidneys. 

At the end of the day Subaru built a bunch of turbo Subarus. They didn't really think people would buy the base models and upgrade. 

[ZuluKing]

It’s really just something I wanted to do and try. Wasn’t much info I could find on it. My 09 2.5i came 5 speed, but when I bought the ej20x it came with a tranny, ecu and harness. I didn’t believe it was as simply as plug and play, and that’s what I’m simply trying to find out 

[KZJonny]

Hey dude,

I'll generally be the last person to tell a person that they cannot do a thing. Should not? Perhaps, but I've too often seen people told "you can't do that", then they turn around and pull it off. In the world of my other project car, engine swaps are common and extremely varied. I've watched as people pulled off projects they'd been told by plenty of others they'd never finish, or that weren't possible. On the other hand, I've seen quite a few that ended in lots of dollars spent, hit a brick wall and either get sold off half finished, or the person just stopped posting. Such is life. All that being said, the people who generally were able to finish some of the tricky ones were crack fabricators, able to make and weld parts out of steel and/or aluminum, form CF from homemade molds, etc.... a very broad skill set and the money to back it up.

You won't find a walk through for what you're trying to do, not here. BUT, you may find @RumblyXT's thread on his EJ20Y engine swap useful. He goes through all the process with lots of photos, however, he is replaceing en EJ255/7 so everything in the car is already set up for a turbo engine, and as mentioned above, you can trick the ECU into working with it. (Sounds like you already have and ECU and trans, so there is part of the problem solved.)

Aside from making sure the EJ20 you have is healthy, making sure all the gaskets are good, and ready for service, (which even if it is "low mile",  is 100x easier with the engine out of the bay, so now is a good time) there are a couple of other things you are going to want to consider if you decide to try and put a turbo engine in your NA shell.

-Wiring will be the big one, making the JDM ECU talk to a USDM (?) car, and they may not be very happy doing it. If you have complete wiring diagrams from the donor car and for yours, repinning should be possible. very nice that you have the engine harness. Lots of hours of work to be sure, but probably doable. Remembering tho, nobody but nobody around here tunes JDM ECU's... If you go this route, you're probably stuck with the stock tune, unless you decide to find a USDM ECU and go that way from the start, but then you lose the exhaust cam AVCS. Maybe there are other options? STi ECU from a year that is quad cam AVCS, but now it won't be happy talking to an old Legacy chassis. Piggyback? Standalone? $$$!!!

- as mentioned before: complete exhaust system. I am not even sure the engine subframes are the same between NA and turbo, since the piping path for UP and DP does not exist on the NA car. I think they're different, but am not sure.

- cooling? I am also pretty sure that the NA cooling system has less capacity than a turbo car... new rad and fans are probably required.

- as above; brakes. Add nearly 50% HP to a car and you're definitely going to need more stopping power. NA Legacy braked are fine for the 150HP it comes with, NOT 250 (ish) So, calipers, rotors, probably a bigger master cylinder, etc..

- fuel system: NA car fuel pump and FPR are not gonna cut it. Complete aftermarket replacement or swap from a GT.

- as above: if using the provided JDM ECU, defeat the security system/chips in the keys. Dealership may be able to rewrite this for you, but unlikely for a car this old, and especially a JDM unit. I very much doubt the North America SSM's came with the parameters for those.

 

There are a handful of other things you may or may not want to address. You won't have the GT steering rack and it's faster ratio, but that's not required, and you can get away without replaceing the hood with a scooped one, if you go to a FMIC, etc...... more heat sheilding in the bay etc....

 

If you decide to plunge on ahead with this, people here will probably be able to help you a little. But for a lot of it you'll be on your own, or spending hours going through wiring diagrams. Seriously, I am not saying don't do it, but DO take a look at the list of "things to do" and imagine some of the price tags associated with each. I'm very willing to bet that if you're honest with yourself, you'll end up with a final price on just the above that is a lot more than buying a running LGT, and you're going to end up with a car with a smaller engine and very little support. If it's more than just the price tag to you, it's about the doing of it, then go for it. 

I'll say for reference, I am probably $8-10K (CSD) into my LGT, and it came to me as a relatively clean, if slightly rusty very low km car. And that price is for a lightly modified car with maybe 270whp that just handles nicely and has some of the reliability things worked out... not even a fast car....

Edited September 26, 2023 by KZJonny

[KZJonny]

https://b-pro.ca/car/2005-subaru-legacy-touring-wagon-2-0gt-spec-b-142102km/

Just as a comparison.

For 7.5K CAD, so.... something like 5K USD? You could just buy an EJ20 powered LGT with....90k miles on it? That's a Canadian site, but it's a good number anyway, and that price is LANDED AND CUSTOMS PAID. All you need to do is ship it to you, or go pick it up. I'm sure the same things exist in the US.

Just sayin. I personally do not like RHD on LHD roads, and used to live in New Zealand, so it's not that I haven't spent a couple years driving RHD.

But dollar for dollar, it's pretty hard to beat the price when you consider how clean most cars coming over from Japan are. Hell, you could just shell swap to your Legacy if you want... Considering you get all the LGT good stuff with an engine ECU etc... that all work together, it's still probably less expensive that peicing it together yourself....

[seanyb505]

Two well thought out replies compared to my malarkey. This swap is far beyond bolt ons and ins. Rumbly can attest to that, and his was best case scenario. 

[ZuluKing]

10 hours ago, KZJonny said:

Hey dude,

I'll generally be the last person to tell a person that they cannot do a thing. Should not? Perhaps, but I've too often seen people told "you can't do that", then they turn around and pull it off. In the world of my other project car, engine swaps are common and extremely varied. I've watched as people pulled off projects they'd been told by plenty of others they'd never finish, or that weren't possible. On the other hand, I've seen quite a few that ended in lots of dollars spent, hit a brick wall and either get sold off half finished, or the person just stopped posting. Such is life. All that being said, the people who generally were able to finish some of the tricky ones were crack fabricators, able to make and weld parts out of steel and/or aluminum, form CF from homemade molds, etc.... a very broad skill set and the money to back it up.

You won't find a walk through for what you're trying to do, not here. BUT, you may find @RumblyXT's thread on his EJ20Y engine swap useful. He goes through all the process with lots of photos, however, he is replaceing en EJ255/7 so everything in the car is already set up for a turbo engine, and as mentioned above, you can trick the ECU into working with it. (Sounds like you already have and ECU and trans, so there is part of the problem solved.)

Aside from making sure the EJ20 you have is healthy, making sure all the gaskets are good, and ready for service, (which even if it is "low mile",  is 100x easier with the engine out of the bay, so now is a good time) there are a couple of other things you are going to want to consider if you decide to try and put a turbo engine in your NA shell.

-Wiring will be the big one, making the JDM ECU talk to a USDM (?) car, and they may not be very happy doing it. If you have complete wiring diagrams from the donor car and for yours, repinning should be possible. very nice that you have the engine harness. Lots of hours of work to be sure, but probably doable. Remembering tho, nobody but nobody around here tunes JDM ECU's... If you go this route, you're probably stuck with the stock tune, unless you decide to find a USDM ECU and go that way from the start, but then you lose the exhaust cam AVCS. Maybe there are other options? STi ECU from a year that is quad cam AVCS, but now it won't be happy talking to an old Legacy chassis. Piggyback? Standalone? $$$!!!

- as mentioned before: complete exhaust system. I am not even sure the engine subframes are the same between NA and turbo, since the piping path for UP and DP does not exist on the NA car. I think they're different, but am not sure.

- cooling? I am also pretty sure that the NA cooling system has less capacity than a turbo car... new rad and fans are probably required.

- as above; brakes. Add nearly 50% HP to a car and you're definitely going to need more stopping power. NA Legacy braked are fine for the 150HP it comes with, NOT 250 (ish) So, calipers, rotors, probably a bigger master cylinder, etc..

- fuel system: NA car fuel pump and FPR are not gonna cut it. Complete aftermarket replacement or swap from a GT.

- as above: if using the provided JDM ECU, defeat the security system/chips in the keys. Dealership may be able to rewrite this for you, but unlikely for a car this old, and especially a JDM unit. I very much doubt the North America SSM's came with the parameters for those.

 

There are a handful of other things you may or may not want to address. You won't have the GT steering rack and it's faster ratio, but that's not required, and you can get away without replaceing the hood with a scooped one, if you go to a FMIC, etc...... more heat sheilding in the bay etc....

 

If you decide to plunge on ahead with this, people here will probably be able to help you a little. But for a lot of it you'll be on your own, or spending hours going through wiring diagrams. Seriously, I am not saying don't do it, but DO take a look at the list of "things to do" and imagine some of the price tags associated with each. I'm very willing to bet that if you're honest with yourself, you'll end up with a final price on just the above that is a lot more than buying a running LGT, and you're going to end up with a car with a smaller engine and very little support. If it's more than just the price tag to you, it's about the doing of it, then go for it. 

I'll say for reference, I am probably $8-10K (CSD) into my LGT, and it came to me as a relatively clean, if slightly rusty very low km car. And that price is for a lightly modified car with maybe 270whp that just handles nicely and has some of the reliability things worked out... not even a fast car....

I appreciate you, thank you