2015 Kawasaki Ninja H2 second teaser video confirms supercharger

Second teaser "video" released today only has sound of engine, but noise from supercharger bypass valve heard in background

Typical supercharger bypass valves

The second teaser "video" released by Kawasaki today of its upcoming 2015 Ninja H2 model actually only consists of audio recordings of the engine, but they're telling in that there are additional sounds besides the engine revving as it accelerates at full throttle (of course, Kawasaki couldn't just leave it to discerning ears, so it titles the video "Vol. 2 - Mysterious Sound" followed by the header "Howling and Chirping" as the video begins). As you hear an engine start and accelerate away from stop, you can hear the faint whine of a supercharger, followed by a brief whistling noise every time the throttle is backed off during each upshift and also during each throttle blip on downshifts.

That chirping noise on decel is the sound of a supercharger's bypass valve. Because a supercharger is directly driven by the engine and is constantly force-feeding the intake charge into the engine, the bypass valve is necessary to avoid over-pressurization (known as compressor surge) when the throttle valve is shut. The bypass valve also allows the supercharger to bleed off pressure during cruising throttle situations (when boost pressure isn't needed), reducing the parasitic drag of its components (the drive system for the supercharger and the supercharger itself) to negligible amounts. Because the pressure is being released quickly during gearshifts or throttle blips, the airflow rushing out of the valve creates a whistling or chirping sound.

Although it's pretty much a given that the Ninja H2 will be supercharged based on the engine display at the Tokyo Motor Show last year and the patent drawings discovered earlier, this basically confirms that the bike will indeed have a forced induction engine. The second video is below: