Subaru “Mad Boxer” Turbocharged Motorcycle

Putting any car engine into a motorcycle chassis is a challenge, but putting a turbocharged Subaru WRX engine in one is even more ludicrous – and of course, this story begins like all good stories should: with a dare.

Marcel van Hooijdonk from New Zealand is pretty handy on the tools, so when a friend of his sent him a photo of an opportunistic designer’s concept motorcycle based around a Subaru engine and dared him to build it, he leapt at the opportunity. But one does not simply put a turbocharged Subaru engine into a motorcycle frame, oh no. This was a labor of love that took Marcel five years to complete.

Since the original concept sketch focused on the Subaru power plant, Marcel decided to start with the engine and build the rest of the motorcycle around it. Now, the Subaru WRX came to New Zealand in a wide range of flavors, from 1.5L to 2.5L, but for reasons of either utter madness or pure genius, Marcel opted to use the big 2.5 liter turbocharged Subaru lump as the beating heart of his build. After sticking the engine between two tires and visualizing if the project was even remotely viable, Marcel drew up a plan in his head and got to work.

Building A Turbocharged Subaru Motorcycle

The first step was transposing his mental image into a more physical one. With the aid of a computer, Marcel drew up a CAD mockup, taking the time to design a proper center steering hub, practical swing arms, and the main bulk of the chassis. The computer design was more than just a visual representation of Marcel’s plans too since it would be the blueprint for the Kiwi builder’s CNC machines to work from. There’s another reason the plans were so important, but we’ll get to that later.

Thanks to the plethora of home engineered CNC parts, the addition of a set of wheels, and a fuel tank borrowed from a Kawasaki, the build slowly began to shape. To keep things reasonable, Marcel swapped out the original WRX turbo unit with a smaller twin-turbo borrowed from a Subaru Legacy, and then mated the engine to a modified Japanese 2-speed automatic transmission, that delivers power to the rear while via a chain drive. With no traditional gearbox, there’s no need for a gear lever – instead the gears are engaged using a handlebar mounted button. Like on an automatic scooter, the clutch lever location now looks after a brake that controls the rear brake. The brakes were kindly donated from an old Buell.

So what did Marcel need the CAD drawings for? Well, he needed to submit them to the New Zealand government to make his build road legal. After a few safety tests and after being examined by a panel, it got the all clear. That’s right, Marcel’s shed-built turbocharged Subaru motorcycle is 100% road legal.

“Being able to ride it was the aim right from the get go. The system here in New Zealand isn’t too bad, you forward your design at the beginning and a panel go over it. Once you have approval you can start, but with inspections along the way you can make changes, you always think of something you would like to change which has to then go back to the panel. At times it’s hair pulling, but now it’s all done and 100 percent road legal I must say it wasn’t too bad,” Marcel told New Zealands’ Bike Rider Magazine.

And we’re glad he put the effort in. In the end, the world now has a turbocharged Subaru motorcycle to look at;  a car engine’d motorcycle that weighs in at 690 lbs – which is pretty reasonable considering the size of the engine that it’s lugging around. It might be heavy, but it actually goes – and that’s what makes this build so special.

Source Gear Heads