"Easy" Subaru Swap Engine Choices

"Easy" Subaru Swap Engine Choices

Sep 8, '21
If you go with a 2.0 WRX or STi swap, here is an excellent guide for the entire process with help from our friend Bucky Lasek!

First, there are no truly easy Subaru swaps; every swap has 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 will be used. However, we will get into some more straightforward options below regarding engine choices. 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.

March 2023 Update:

We can no longer wire up engines from cars older than the chassis they are being installed in. The problem is many states are taking the stance, like California, that for any engine change, it must be from the same year or newer, or the car can't pass emissions testing. We've already gotten reports of customers who have done swaps in the past that can no longer pass emissions testing because the engine is older than the car in states like Utah. So, for example, if you have a 2005 Impreza, you would need to swap a 2005+ turbo engine into your vehicle to ensure that even if you don't have an issue today, you'll protect yourself against being unable to register your car in the future. 

The most important tip we can give is to do research before buying anything. Please 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 the engine is essential. The more stock the engine, the simpler the project will be. Please be careful with the 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 start from scratch.


JDM 1993-1998 Engines

Pros: Easy to find and typically inexpensive.

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

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

JDM 1999-2000 Engines

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

Cons: If you want a modern ECU (IE 2002-2005 WRX) for a working OBD2 for smog and straightforward tuning 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 we wouldn't recommend it.

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 the engine, so we 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, then a 2-liter WRX is 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: Challenging 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 six-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 "simple" as pulling the engine from the chassis, swapping the cross member, putting the new engine in, hook up the power steering, AC, exhaust, and radiator. Assuming the wiring harness is sent to us, it would just plug back into the chassis, the new engine, and the car is done. As we mentioned, 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.

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