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"Easy" Subaru Swap Engine Choices

  • Writer: Brian Keene
    Brian Keene
  • May 28, 2019
  • 3 min read

Updated: Sep 2, 2021



If you go with a 2.0 WRX or STi swap, here is a great guide for the entire process with help from our friend Bucky Lasek!


Let us first say, there are no truly easy Subaru swaps and every swap has it's own challenges. A lot of work goes into any swap. There are wiring changes, mount changes, mechanical changes, etc and these all depend on what engine and chassis are going to be used. However, when it comes to engine choices there are some simpler options which we will get into below. Our recommendations are based on putting the engine into a GC (1993-2001) chassis. If you have a different chassis please check out our other blog post with engine recommendations: Best Subaru Engine Swap Choice for your Chassis.

The most important tip we can give is to do research before buying anything. Don't jump on a cheap engine deal before it's confirmed to be compatible with your car. Not all research is good research. Make sure the information is coming from a trusted and experienced source.

Some things to consider before buying an engine:

1. Is it coming with the matching ECU and matching engine and body wiring? If not, those parts will need to be sourced later.

2. Condition of engine is important. The more stock the engine, the simpler the project will be. Be wary of Frankenstein motors.

3. Be wary of second hand parts coming from another project or someone else's project car in general. Most of the time these are more work to fix than to just start from scratch.

JDM 1993-1998 Engines

Pros: Easy to find and typically inexpensive.

Cons: No OBD2 port which makes SMOG and tuning a problem as well as expensive.

iWire Recommendation: Stay away from these engines despite the lure of the low price point.

JDM 1999-200 Engines

Pros: Long block will be good and typically these cars have low mileage.

Cons: If you want a modern ECU (IE 2002-2005 WRX) for a working OBD2 for smog and simple tuning, basically a complete WRX engine is needed for the cam gears, the headers, the intake manifold, etc. It's a lot of work.

iWire Recommendation: Possible to do but wouldn't recommend.

JDM 2001-2005 WRX and STi Engines

Pros: Easy to find, highly compatible with USDM cars, and parts readily available

Cons: Typically mislabeled by importers, not all wiring components come with engine so need to source extra parts.

iWire Recommendation: Go for it. Just make sure that they have AVCS and mechanical cable throttle. If the car does not have AVCS, it is a 99/00 engine. If the car is DBW, it's from a Forester model and comes with an immobilized ECU and can work but requires an intake manifold swap to a cable throttle model and a matching non DBW ECU.

USDM 2002-2007 WRX and STi Engines

Pros: Easy tuning, parts readily available, and ability to pass SMOG.

Cons: Typically high price point with higher mileage

iWire Recommendation: All good options. If you can afford an STi get one because 300 horsepower out of the box is pretty good. If the STi is not in your budget than a 2 liter WRX is a still a great option with easy paths for more power.

USDM 2004-2008 Forester XT Engines

Pros: Easy tuning, parts readily available, and ability to pass SMOG.

Cons: More difficult to find in good condition.

iWire Recommendation: If you can find one in good condition, go for it.

USDM or JDM Legacy Turbo Models

Pros: Easy to find.

Cons: Very difficult to swap due to CANBUS issues.

iWire Recommendation: Stay away from these engines despite the cheap cost.

You didn't see what you are looking at on this list?

It's likely because it's not a good "easy" swap option. These might include 6 cylinder, twin turbo platforms, newer than 2007 engines that are CANBUS equipped, ETC. If you are looking at one of these contact us before purchasing and we can determine whether it's a good choice for your project.

So what's our recommendation for the simplest swap with cost in mind? For a GC Chassis (1993-2001 Subaru) we suggest a 2001-2005 JDM WRX (EJ205/7 or V7/8) or a 2002-2007 USDM WRX or STi. To do this swap the steps are as as "simple" as, pull the engine from the chassis, swap the cross member, put the new engine in, hook up power steering, AC, exhaust, and radiator. Assuming the wiring harness is sent to us, it would just plug back into the chassis and the new engine and the car is done. As we mentioned before all swaps take time, cost money, and are a lot of work. Make sure to research and check your budget before purchasing a new engine or taking apart your car.

Want us to help with wiring up your Subaru swap project? Check out our services here.

12 Comments


Erma San
Erma San
Oct 24, 2021

I have a USDM NA 99 Sf Forester and I'm looking to do a JDM EJ207 V7 swap. What kind of issues should I look out for? Will a standalone ecu work? Is it the best route?

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Brian Keene
Brian Keene
Oct 25, 2021
Replying to

We would recommend utilizing the stock ECU that matches the engine. Here’s some info on a similar swap - https://www.iwireservices.com/post/how-to-do-a-subaru-wrx-swap-into-a-rs

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stubbs.logan213
Oct 02, 2021

Just got a great deal on a 02-05 jdm ej205 and matching trans. Aside from ordering a radiator, stock ecu, and wiring harness to send to iwire what elese would I need to swap into my 00 2.5 rs (gc6)?

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Brian Keene
Brian Keene
Oct 25, 2021
Replying to

My apologies, just saw this comment. Here’s a blog with more details about your swap - https://www.iwireservices.com/post/how-to-do-a-subaru-wrx-swap-into-a-rs

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driftcorona23
Aug 24, 2021

I have a 2002 Impreza wagon with ej15 that’s dead and wanting to put ej16 out of 98 Impreza wagon I have sitting around,, the manifolds are different so can’t just swap them over, does any one have any help on easiest way I can go about it

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Brian Keene
Brian Keene
Aug 24, 2021
Replying to

Unfortunately that swap won't work due to the phase 1 vs phase 2 differences. https://www.iwireservices.com/post/phase-1-vs-phase-2-subaru

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Bob Zormeir
Bob Zormeir
Jul 28, 2021

I've got a 2013 WRX with a blown engine. 2013 long blocks don't seem to be available. Can I use a 2015 long block instead?

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Brian Keene
Brian Keene
Jul 28, 2021
Replying to

This blog post will give you the answer :) https://www.iwireservices.com/post/my-subaru-engine-blew-up-what-should-i-replace-it-with

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MC
MC
Jul 08, 2021

It's there anybody out there that can tell me if is possible to install a 2.0 wrx turbo engine into my 2010 subaru impreza 2.5 non turbo hatchback? Unfortunately I blew the motor recently and I need an engine.

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Brian Keene
Brian Keene
Jul 08, 2021
Replying to

Hello, we wouldn't recommend the turbo swap since the 2010 impreza is a CANbus equipped car which makes things difficult. Here's a blog on how to find a compatible replacement. https://www.iwireservices.com/post/my-subaru-engine-blew-up-what-should-i-replace-it-with

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