We know that Yamaha has been working on turbocharged engines for a little while. Last year we picked up on a patent filing for a turbo twin, essentially the engine from the MT-09 with one cylinder lopped off. Yamaha has now built and tested a prototype motorcycle, but with a twist: a full-size three-cylinder turbocharged engine.
This isn't just an MT-09 engine with a turbo slapped on, either. While this engine's displacement matches the MT-09's 847cc, its 73mm stroke is longer than the standard engine, while its 67.5mm bore is smaller. This puts more emphasis on low-end torque, like a diesel, rather than high-end horsepower. That's not to say that horsepower is lacking, however—far from it, with a maximum 180 hp at 8,500 RPM, with 130 pound-feet of torque. At least 90 percent of that torque is available all the way from 3,000 to 7,000 RPM as well. That's better than the V-Max muscle cruiser with an engine almost twice as big.
Power is great, for sure, but in this day and age emissions are even more important. If an engine doesn't pass emission testing, it can't be sold. Forced induction has become a popular way to improve emissions in the automotive world, and if Yamaha's results are any indication, motorcycles may follow suit. All this performance comes with less than half the carbon monoxide, NOx, and hydrocarbon emissions allowed under the Euro 5 rules due to take effect in January 2021 unless manufacturers get the delay they want. Direct fuel injection and variable valve timing also help, as well as the engine's low-revving nature.
Don't expect to see a turbo MT-09 next year, though. Yamaha is still very much in the research and development phase. The engine resides in a heavily modified MT-10, not an MT-09. The radiator, ejected from its normal home by the turbo system, sits far too exposed and close to the ground to be practical. This is an easy problem to solve in a ground-up design, but Yamaha's engineers are still using what they already have the best they can before that happens. With future Euro 6 emission standards yet to be announced, it's likely that Yamaha will continue to experiment until they know where that goalpost is.
Can we expect to see a Yamaha competitor to the insane supercharged Kawasaki Ninja 2 in the future? Possibly. They're already close to the H2's 197 horsepower in street trim, plus better torque. I'd expect emissions to play a bigger role in guiding future turbo and supercharged motorcycle design than a horsepower war, though. Such is life in the 21st century.
Sources: Free Patents Online, Patentscope, Cycle World