It’s got a claimed 310bhp (we saw 249.76bhp at the rear wheel on the dyno), a supercharger and can hit over 200mph with normal people like me and you riding it. Some will say the power is too much, it’s too fast, too expensive, too vicious, and yes – it’s all those things, but who cares? I wouldn’t if I had £41k to spend on an H2R.
The H2R feels like a completely new different bike to its H2 road-bike sibling. It’s 22kg lighter than the H2, turns easier, holds its line better. The suspension is the same between the H2 and R but it has to deal with less weight and the settings are more suited to the track, firmer. I makes you feel like a GP rider; the noise, the speed, the power. It’s insane and sublime in equal measure.
Kawasaki chose to use the most efficient of all blower types, a centrifugal supercharger, in which a spinning impeller rotates at phenomenal speed to shove air into a plenum chamber – or airbox to you and me – where all that velocity is converted into pressure.
The importance of high efficiency is that power-robbing heat gain is minimal, and the H2’s high adiabatic efficiency means that it can be run without the need for a bulky and complicated intercooler, saving weight and space.
Machined from a single forged block of aluminium using 5-axis CNC machining, the 69mm impeller has 6 blades at its tip and 12 blades at its base, all with grooves etched into the blade surfaces to help direct the airflow. The impeller’s pumping capacity at full speed is an incredible 200+ litres per second.
The aluminium airbox has a 6-litre capacity, and the pressure inside will increase to as much as 2.4 times atmospheric pressure, which is why it’s not the usual plastic construction. The aluminum is also claimed to act as a radiator for the pressurised air, keeping it as cool as possible before it enters the intake port. All that pressure has to go somewhere when you shut the throttle, which is why you can hear the H2 squeaking during gearshits (see and hear it in action on ), or as the throtle is closed. This the airbox pressure relief valve venting. Psssh.
The supercharger is driven by a planetary gear train, which runs off the crankshaft, resulting in a very compact unit, with minimal power loss. The gear train increases the impeller speed to 9.2 times the crank speed via 1.15x step gear and 8x planetary gear. This means that at maximum engine speed on the H2R, circa 14,000rpm, the impeller shaft is spinning at almost 130,000rpm.
The intake ports are polished to ensure smooth flow and minimise resistance, while the exhaust ports are straight, and don’t converge in the cylinder head, promoting faster gas flow. The high-lift cams allow fast gas exchange, while a wide overlap means intake air is used to help purge the exhaust gases.
The combustion chamber employs a flat piston crown to help prevent engine knock. The intake valves are stainless steel, but the exhaust valves needed to be able to handle the supercharged engine’s high-temperature exhaust gases, so comprise an inconel head fricton-welded to a steel stem. The pistons are also cast rather than forged to offer better heat management properties.
The naysayers, mainly other motorcycle manufacturers, claimed Kawasaki had dropped the ball by omitting an intercooler. It’ll never work they said. Well, it does. As well their supercharger being inherently heat efficient, Kawasaki have done everything they can to keep the engine temperature low. The chassis design, lack of lower fairings, water-cooled oil cooler, and large coolant passageways all dump heat fast. The water jacket even extends between the twin exhaust ports of each cylinder, and around the spark plug holes to whip heat away.
To facilitate smooth, fast shifting, the H2s use a dog-ring type transmission, developed with feedback from the Kawasaki Racing Team. Unlike a standard gearbox in which shift forks slide the gears into position, with a dog-ring transmission the gears all stay in place, and the dog rings slide into position to engage the desired gear. It makes for a lighter, smoother, and stronger gearbox.
The H2R comes with a plethora of control systems to stop it firing you at the scenery, the highlights are:
KTRC (Kawasaki TRaction Control)
The new KTRC system’s multi-level modes give riders a greater number of settings to choose from. Mode 1 is for the track, Mode 2 for the street, and Mode 3 for wet conditions. A Rain Mode is also available separately, which limits power by more than 50%.
KLCM (Kawasaki Launch Control Mode)
There’s no need to fear the supercharger for fast getaways, as the H2’s launch control will prevent wheelspin and minimise wheelies off the line. Riders can choose from three modes, each offering a progressively greater level of intrusion. Simply hold the throttle wide open, and let the clutch out. KLCM can be used concurrently with KTRC.
KEBC (Kawasaki Engine Brake Control)
The KEBC system allows riders to select the amount of engine braking they prefer. By selecting ‘LIGHT’ in the KEBC settings, for example, the engine braking effect is reduced, providing less interference when riding on the circuit.