Firstly, let’s address the elephant in the room: why would you want to flat-six swap your Subaru? The real question is, why wouldn’t you? The most critical issues to consider are reliability and performance. When comparing stock to stock, EZ engines deliver superior reliability compared to EJ engines—period. The EZ lineup was overengineered in comparison to its four cylinder counterparts. They use a timing chain instead of a timing belt, an aluminum block with factory cylinder sleeves ensuring higher durability. These elements ensure that EZ engines are built the way a flat engine should be. However, they are not without fault; for example, the EZ36 has asymmetric rods, and all three models can experience oiling and cooling drawbacks in high-performance applications, but we plan to address these issues.

Regarding performance, the benefits of the EZ engines become clear. The weight difference between EZ and EJ engines is negligible, and the EZ engine is only about 2 cm longer in footprint than an EJ. Both generations of the EZ30 can reliably support 400 horsepower on factory internals, with even greater numbers achievable at a fraction of the cost associated with four-cylinder Subaru performance modifications. Cost-effectiveness is a major consideration. If you plan to build your engine, numerous EZ engines are likely sitting in scrapyards near you for just a few hundred dollars, ready to be taken. Alternatively, JDM EZ30 engines are available online for under $2,000, while EZ36 engines go for around $3,000. The money saved by choosing an EZ over an EJ will ultimately give you an advantage in generating significantly more power, and with greater reliability.

While earlier generations of Subaru flat-six engines exist, our focus is solely on the EZ engine family. We have all three EZ models in-house and are currently prototyping parts for them. Our primary goal is to make swapping these engines more accessible. Currently, if you want to perform a flat-six Subaru swap, you have to handle everything yourself. This includes sorting out wiring in the engine bay, dashboard, chassis, and making complex modifications to the wiring harness depending on your build platform. There are also wiring and software adjustments to consider, as well as exhaust routing conflicts, especially if you want to use a manual transmission. Additionally, interior trim choices often depend on the wiring you select. We aim to simplify this process. Working with our partners at ReetWire, we plan to provide various wiring conversions to eliminate the wiring headaches associated with engine swaps. We are also developing flat-six cross-platform exhaust systems for both automatic and manual transmission applications. This means that swapping your Subaru will no longer entail navigating a maze of decisions and complications; instead, you’ll have various options to choose from that best suit your needs!

In addition to improving general swap accessibility, we intend to offer a variety of performance upgrades. The second most significant drawback of the flat-six family is the lack of aftermarket support. We have secured industry support for components such as engine internals, billet oil sumps, tuning software, and performance wiring solutions, so you don’t have to hunt them down. We are also developing our line of turbo systems for all three EZ platforms, providing everything from mild performance-enhancing kits including bolt-on options for late model EZ36R cars, allowing your Outback to outperform a WRX in a straight line while still maintaining the factory functionality of Subaru Eyesight. We also plan to offer complete kits to break records on the dyno with your EZ30D or EZ30R car. Additionally, we will offer parts individually to enhance any existing performance modifications. We aim to design and produce the first EZ platform dry sump kit and collaborate with industry partners to provide various fuel management solutions. We’ve got you covered from A to Z in EZ engine performance.

Regardless of your interests, feel free to reach out! We want to help you navigate your build plans. We have experience and resources to guide you in the right direction. We’ll also have R&D opportunities to assist you. If you have a build in mind that we haven't yet tackled, we would love to help you move forward at a discounted rate to aid in the development of new products using your vehicle! We are based near Portland, OR, but can collaborate with you remotely, depending on your needs. Don’t hesitate to contact us through our contact page or via email at sales@speedforgeperformance.com.