Subaru Project Do's and Don'ts

Subaru Project Do's and Don'ts

Apr 15, '21
iWire has been a part of a few thousand Subaru project over the years. We thought it would be a good idea to give some general tips to people doing Subaru projects of their own. Below are some do's and don'ts that we recommend for almost every Subaru project whether it's a small repair or a full build.

Do – Research. Good Research!

Not all research is good research. That random guy on the Facebook group may not know what they’re doing. Utilize verified sources for information. We can’t stress this enough. There is a lot of incorrect or incomplete information about Subarus on the internet, especially about the wiring, so be selective about what you listen to. A great place to research the wiring and engine compatibility is the iWire Blog.


Don’t – Trust Your Buddy Who Has Never Done It Before

If your friend is a Subaru Master Tech at your local dealership, they probably have some idea what they are talking about. If your friend is a random guy you meet at a Subaru meet, they may have some general knowledge. If your friend has literally never touched or driven a Subaru before, maybe don’t trust them that your project will be super easy. Be wary of "experts" on social media. A second opinion about a project is never a bad idea.


Do – Know What Engine You Have

Some engines are easier to work with than others depending on your chassis. Make sure to check compatibility BEFORE purchasing anything. Just because someone says it’s plug and play doesn’t mean it’s true.


Watch this video to help identify your engine:


One big tip here – make sure the camshaft position sensors match! Check out some of our engine blog posts below:

Don’t – Buy An Engine Just Because It’s Cheap

Is that 6 cylinder a good deal? Is the JDM importer selling an engine for a steal? Is there a part out you have to purchase ASAP? That’s great BUT sometimes the build becomes more expensive due to the engine choice. 6 cylinders are a decent, inexpensive engine but everything else is custom so it tends to be an expensive build. More about that here

From our experience, no matter how much the engine costs an engine swap will be at least $5,000. So a $500 engine will require more expense (custom wiring, standalone ECU, missing/hard to find parts, etc) to get it to fit and work than a $2500 engine (parts are available and cheap, wiring is straight forward, tuning is simple etc).


Do – Plan Out Your Budget in Advance

When doing a swap there is a lot to consider budget wise. What parts will you need? Will you need to pay someone to install it? Will you need to store the car somewhere? There can be some surprise costs along the way as well so make sure to budget accordingly. It’s better to wait, save up, and buy better parts instead of slapping in an inexpensive part that is a struggle to work with.


Don’t – Install Too Many Modifications At Once

Our biggest recommendation for doing any build is to make upgrades one at a time or in small strategic groups. That way if the car doesn’t run as expected, you have an idea of where to start for troubleshooting. If you change too many variables at once, it’s a lot harder to figure out what’s wrong.


Do - Plan Your End Goal For The Car

Are you planning to race the car? Do you want to make high horsepower? Do you want a reliable daily driver? Knowing the goal before purchasing parts and making plans will make things down the line go much smoother.


Do – Look into Making the Build Legal

Whether you don't have emissions or have to go through the full BAR process, know what standards you need to meet to make your project legal. In our mind, the whole point of building the car is to take it out on the street to drive it. It’s a lot easier to plan your build with this in mind instead of finding out later and having to make changes.


Do - Think About Which ECU You Plan To Use

We typically recommend the OEM (stock) ECU for most projects when possible. Subaru has done a good job designing it to run all of the features desired in your car. Sometimes using the OEM ECU is not possible (ex: CANbus engine in a non CANbus car). In these scenarios you could also go standalone ECU like Haltech or AEM but this will bring up the cost of the project. Knowing which computer you plan to use to run the engine at the beginning will help dictate what parts you use in the future. Check out our blog post for more details - Stock ECU vs Standalone ECU


Don’t – Purchase Someone’s Unfinished Project

It’s a lot harder to untangle someone’s mistakes than to start from scratch. Unless you really inspect the car before purchasing, which is difficult to do, you don’t know what you’re going to get. That easy project to finish could turn into a lawn ornament. Sorry "Bring a Trailer" and Craigslist sellers!


Do – Use Reliable Brands

Before purchasing parts or using a company for mechanical help, check them out. Call their customer support and see if anyone helps you. Look at their reviews and see what people say. Ask friends/other car lovers who they’ve used and liked. Doing a build is much more enjoyable when you’re able to get the help you need along the way.


Don’t – Swap Your Daily Driver

We can't say this one enough, do not do an engine swap on your daily driver!!! We fully expect the projects we work on to be reliable enough to become daily drivers, but there are always surprises in the time that it takes to get it to that point. Doing a swap takes a lot of time and money. Please don’t swap the car that gets you to school or work. We have had customers in the past that have had to take Uber/Lyft/Taxis to work for months while they waited on parts or a tune.


Do – Make Friends With The Right People

Friends don’t let friends buy junk. Making connections in the Subaru world not only makes your projects easier (and maybe cheaper) but you’re building relationships with good people who also love cars. #Subarubros4lyfe


Do – Look Up Terms and Educate Yourself

- Some good terms to know include:


Do – Know Your Limits

Whether your limit is time, money, or skill it’s important to know your limits and plan accordingly. Short on time? Maybe don’t do that fully custom race car. Don’t have a large budget? Pick a tried and true engine swap (IE 2.0 WRX platform in a RS). We want every person to build their dream car but we also recommend being strategic and setting realistic goals to make sure you do end up building your dream car.


Can you think of some do's and don'ts we missed? Let us know in the comments below!