Engine swap for 2010 Legacy 2.5i 6MT

[Neben_PL]

So I have a 2010 Subaru Legacy 2.5i Premium with a 6 speed manual with 153k miles. The other day the motor started knocking and I have other small ongoing issues as well, and decided to purchase a 2003 JDM EJ206 TT to swap into it.

 

I’m not very knowledgeable when it comes to swapping engines and exactly what all I need. What are the absolute essentials needed for a swap?

 

It was something I was not planning on doing for a little while, but since the opportunity presented itself I took it. I do have time and money to do the swap and take care of any other modifications necessary to make the swap happen, I just don’t know where to start. Any suggestions or advice is greatly appreciated!

[Infosecdad]

What in your research for replacement engines indicated that this would work?

 

That's gonna be a serious challenge, how much time, money, and tools do you have?

 

So, you are going two generations older on engine and a different market.

 

Your 5th gen has a very different engine mounting system, I'm not sure you can actually mount the '03 engine in your bay since your chassis is designed to have a mount on the front of the engine block and that concept didn't exist in 2003.

 

Are you planning to keep the twin turbo?

You will likely need a full exhaust setup, wiring, and engine management, your 2010 ECU most likely can't manage that engine.

Also, not sure if you can get the turbos around your steering and brake systems.

 

It's probably not impossible, but even getting a 2010 2.5 turbo would be a challenge, much less this engine.

 

Are you just really wanting to go with a turbo engine? I would generally recommend just going with a new short block if it's something you want to keep for a while.

I'm all about turbos, but this really sounds like a nightmare in the making (unless you have a ton of time and interest in just doing something that no one else has possibly done yet).

Edited February 6, 2022 by Infosecdad

[FLlegacy]

This swap is not something thats been attempted and for good reason. You need to really speak with someone about tuning and wiring to even get this project off the ground, and you need to understand how much time you will need to invest to make it happen.

 

The engine will physically bolt in, but this will turn your car into a rolling project forevermore. Unless this is a project/fun vehicle I wouldn't do it for something I need to get me around on a daily basis.

Edited February 7, 2022 by FLlegacy

[Aphex28]

The ej206 is essentially hot garbage. A huge valley of death in the middle of the powerband along with a huge rats nest of vaccum lines and fittings where especially with the age of them now will be brittle and leaking.

 

I don't think anybody has stayed Left hand Drive and been able to use both turbos. the Steering column, brake and clutch masters will interfere with that side's turbo and exhaust.

 

You can convert your car into right hand drive if you got a whole front clip, a plasma cutter and mig/tig welder, but the novelty of having a Right hand drive car in a LHD country wears off fast when it is really hard to make left turns and merge onto highways safely. But again, you do this to have an inconsistent powerband and pretty prehistoric engine in the car.

 

Onto the wiring: You may be able to make it work if you convert it to using a standalone ecu to take care of the engine duties. (This option you will not be able to plug into OBD-II and pass inspection.

 

 

Using a stock/merged wiring harness is quite a challenge that only IWire has ALMOST done to a point to where it can be inspected and driving on public roads.

The main contention is that the 08+ cars use the CANBUS network to communicate between multiple sensors and the ECU. If the harness that's being merged in can't communicate (I'm paraphrasing A LOT) the car's immobilizer and network will not work.