Honda is also working on turbo-charged motorcycle, as one of the last big four Japanese manufacturers, Honda applied for several patents suggesting a supercharged or turbocharged engine with strict exhaust emission control is coming soon from Honda Big Wing.
Honda appears to be working on at least two designs. One is a parallel twin – effectively the front half of the VRF1200F's SOHC V-4 engine – with a supercharger/turbocharged but surely forced induction technology located where you'd normally find the rear cylinder bank and an intercooler mounted above it, where the airbox usually resides. That should be enough hardware to boost performance back up toward something like the 160 crankshaft horsepower produced by the current VFR1200F, with just half the displacement.
The second design is something more intriguing – an inline-four with a small supercharger mounted down low and in front of the crankshaft. The engine uses reversed cylinder architecture, with the intake at the front and the exhaust at the rear and the cylinder bank is telted slightly backwards relative to the motorcycle's frame, much like the layout used on Honda's NSF250R Moto3 racebike.
The impetus behind these designs – and those of Honda's rivals – is forthcoming legislation in Europe, expected around 2017, that will force motorcycle manufacturers to quote CO2 levels their machines produce. Many European states already tax cars according to CO2 emissions, and once figures for motorcycles become available it's expected they'll be taxed as well, adding further pressure to reduce CO2 emissions and fuel consumption.
From the patents requested by Honda it's not 100% clear if Honda would go for a turbo-charged, Supercharged or even some sort of hybrid between the two technologies.
Forced induction is becoming virtually required on cars as a result of CO2 emissions and fuel consumption pressures, and the same is predicted to happen to motorcycles over the next few years, too. Normally aspirated high-performance cars are a dying breed; we may well soon be looking at the last generation of fast, large-displacement, normally aspirated motorcycles, too.