I believe that the supercharged motor that Kawasaki rocked the world with a couple of years ago in the manic H2 has come home. The H2-SX is Kawasaki’s Sports Touring version of the Sports orientated H2. It is the plain Jane version of the SE model that has all the bells and whistles.
The supercharged motor has been tweaked for sports touring duty and, if the truth be known, it is all the better for it. Let us just digress for a moment, and, for the benefit of the less technically minded readers, try and explain in simple terms what a supercharger does to boost engine power. Turbos have become commonplace in cars these days, but only Mini and Mercedes have really utilised superchargers. So, you may ask, what is the difference? A turbo is a pump which is driven by the exhaust gas expelled from an engine during the combustion process. The gas spins an impeller which builds pressure, or boost, in turbo speak, to force more mixture into the motor via the fuel injection, resulting in more power. Problem, especially in small capacity motors is that it takes a little time for the pressure to build, resulting in “lag”. The other side of the coin is that once boosting, the pressure remains high for a short time after you come off the throttle, a phenomenon called “over boost”.
The other force fed motor, and the type used by the H2, is a supercharger. As with a turbo, the supercharger uses an impeller driven pump to build pressure in the inlet manifold. Big difference is that the supercharger is driven by a gear, belt or chain that is connected to the crankshaft. As the motor turns over, the pump immediately starts to turn and the pressure builds exponentially as the revs climb. The H2-SX turns the supercharger at 9.2 times crank speed. So even at a sedate 3000 rpm, the blower [petrolhead name for a supercharger] is spinning the pump impeller 27600 times every minute. At redline, the pump is spinning at a heady 110000 rpm!
Turbos, being spun by exhaust gas, have to contend with the heat of the gas. Hence the use of intercoolers, a radiator between the turbo and the manifold, to try and cool the gas. Firstly to help the engine run cooler and secondly, to make the charge more dense for better combustion and thus more power. Blowers run much cooler, resulting in obvious benefits to the engine. Having said that, force fed motors burn more mixture and tend to generate more heat than normally aspirated mills.
On the SX, Kawasaki tweaked the blower for more midrange power. The intake manifold shrunk slightly, creating more pressure, and they subtly reshaped the impeller for more pressure at moderate revs. The result is quite frankly spectacular! In the real world, the SX motor stomps that of the original H2. Reprofiled cams make the most of these tweaks to produce power from right out of the basement. Interestingly the compression ratio is 11.2 to 1, which is high for a force fed motor. The original H2 is 6.5 to 1. Sophisticated engine management prevents engine destroying detonation, thereby keeping everything under control. Like the original H2 the SX carries the “Rivermark”, Kawasaki’s mark of engineering excellence, and rightly so.
This is as magnificent a motorcycle engine as you will ever experience. Power characteristics are akin to Kawasaki’s own ZX 1400, or Suzuki’s Hyabusa. Perhaps a smidgen les grunt, but as it starts to rev the SX gathers speed with absolute disdain. The motor is silky smooth at all times, with an incredible “whoosh” of shove propelling you towards the horizon at ever increasing velocity. Nothing dents the power. One up, two up, or even five up if it could, that fantastic engine just goes. Your pace may be limited by road conditions, but never by the motor. Adding to the pleasure is a clearly audible chirp from the waste gate on the supercharger, as it bleeds off excess pressure between high speed shifts, as you fly through the box with the aid of the quickshifter. Jumping on the gas and listening to what could be a symphony of squirrels shouting the odds at every shift, must be experienced to be appreciated.
The finest motor in the world would be of little use if you couldn’t use it. No problem in this regard. The SX is so composed, with such excellent suspension compliance, that I believe that this is the quintessential superbike for the current world. The extra weight of the bike allows the suspension to work without losing your fillings, as on the current crop of Sportbikes. Allied to the superb ride quality is the stability that comes with the longer wheelbase. A steering damper is superfluous on this bike. At all speeds over all surfaces it goes where you point it. Super light sports weapons feel flighty over anything but billiard table smooth tar. The SX shrugs of bumps and says, “bring it on” !.
High speed sweeps are food and drink for this bike. It is deceptively fast point to point, due to it’s amazing overall ability and rider confidence which it inspires. I rode the bike day to day, as I do with all bikes. It is so easy to live with due to the overall refinement. The only thing I can criticize is the dash display which is hard to read with a dark visor on your helmet. The TFT display on the SE model will address this. That is it! For the rest, the bike is flawless when it comes to real world riding.
The tank holds 19 litres, allowing decent touring range if you ride with some restraint. Good luck to you! The thrill of using the brilliant power delivery to the full is so intoxicating, it takes a better man than me to cruise at 140ish. Lean hard on the gas and the fuel gauge drops faster than a brides nightie! I did manage 18,4km/l on the last tank of fuel I fed the beast. The bike weighs 256Kg’s, but as is the case with so many modern bikes, mass centralisation and careful packaging negates the weight on the move. 137,7 Nm of twist @ 9,500 rpm allied to 210 odd horses, give it the incredible go it exhibits. Remember that force fed motors create there own atmospheres, so there is no loss of power at altitude. Your normally aspirated crotch rocket sheds 18% of it’s power on the reef. The bodywork offers better protection than it’s H2 sibling. It is easy to tuck in slightly behind the fairing as you conduct the orchestra. The test bike was a stealthy dark silver colour. Subtle touches of metallic green on the shock spring and preload adjuster, as well as the damping adjusters, add to the overall classy look.
The wheels are star shaped and beautiful and sport offset tyre valves to facilitate pumping your tyres. Nice. Said wheels are 17 inchers front and rear, with a 120 and 190 respectively. 287mm twin front discs and a 223mm rear take care of braking. A word of caution. The brakes work perfectly, however, such is the deceptive and effortless manner in which this bike piles on pace, you can easily find yourself going 20Kph faster than planned!
I truly loved my time with this bike. It is the Porsche Panemera Turbo of the motorcycle world. With it’s thoroughly modern styling, brilliant electronics, [traction control, engine modes, ABS and quick shifter] magnificent motor and superb refinement, it is simply superb!
From it’s unique chuntering idle to the rabid squirrel power shifts, it never fails to thrill. Kawasaki I applaud the H2-SX. There is literally nothing like it. There is no better way to spend R260K!
For more information visit: www.kawasaki.co.za
