There is customizing motorcycle and there is building an entire motorcycle around an engine. Meet, Madboxer, a custom bike built around a 2500cc Subaru Impreza WRX’s boxer engine!
We love engine swaps, if you follow up with us, you might have already seen our coverage on a few engine swap builds. Well, this week we have something different to show you. Meet this custom bike with a Subaru Impreza WRX engine. The Madboxer was designed and developed by Marcel van Hooijdonk from New Zealand.
A toolmaker by nature, Marcel van Hooijdonk started this build after one of his friends sent him an email with a photo issuing a challenge. So, he went ahead and put his skills to use in building something pretty different.
“It all started off as a bit of a challenge from a mate in Aussie, Harry; who came across an artist’s impression of a Subaru-powered motorcycle concept—with the comment “something for you to knock up in the shed, mate,” says Marcel.
Marcel started the build by sourcing a Subaru engine. He came across an array of readily available Subaru EJ engines in NZ. He came across engines ranging from 1.5 to 2.5 litres, however, in the end, Marcel went with a turbocharged EJ25 mill from a 2nd generation Subaru Impreza WRX. After sourcing the engine and the required components, Marcel put them in place to make sure the “bike” is something that’s doable.
“I got a motor case and some tires, spaced it out, stepped back and grabbed a beer,” he says. After eyeballing it and putting together the mental plan on just how to proceed, the decision was made. “Yes, it’s doable.”
Following that, Marcel had to lay the groundwork for the build so he started with his computer and put together a set of CAD drawings. As he wanted the bike to be road legal, Marcel had to sign off from the regulatory body which covers all modified vehicles in NZ, LVVTA (Low Volume Vehicle Technical Association).
“Once I had the motor block and wheels in place I started in AutoCAD; making drawings of the centre steer hub, swing arms and the main chassis sides, he says. The drawings were also used for programming the CNC milling centre and lathe, which carved out the individual pieces of the bike ready for assembly.”
Well, Marcel says it wasn’t a simple job to get everything right. Not just in “right” working order, but also to comply with the regulations set by the certification panel.
Marcel had to work on the steering system to get approved by LVVTA. Looking at the steering system in the pictures we are actually mindblown by Marcel’s talent!
Following the steering system, Marcel sourced a Kawasaki fuel tank and a smaller Subaru Legacy twin-turbo snails online to replace the big WRX turbocharger.
Wondering about the gearbox? Well, Marcel went with a modified 2-speed automatic transmission with a chain final drive to transmit the power to the rear wheel. The Madboxer doesn’t have any lever on footpegs to change gears; instead, the gears are changed using buttons on the handlebar. As for brakes, the bar-mounted lever controls the Buell sourced brakes just like a scooter.
Weighing in about 313.5 kg, it’s heavy for a motorcycle. However, the boxer engine mounted low in the chassis, it holds the weight in the lower section. On top of this, the twin-turbo boxer engine gives more than enough ponies and torque to make the bike fly down the road.
Madboxer gets on the road!
However, after Marcel completed the build, Marcel somehow fought it out with LVVTA to get the Madboxer certified! Isn’t it pretty crazy to think this bike is actually road-legal?
“Being able to ride it was the aim right from the get-go,” Marcel explains. “So that did impact on the final design. The system here in NZ is not too bad; you forward your design at the beginning and a panel goes over it. Once you have approval you can start, but with inspections along the way.”
“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 per cent road legal, I must say it wasn’t too bad.”