According to official horsepower numbers published by Canadian Kawasaki, the North American market 2011 Kawasaki ZX-10R will have its power dropped from 197 to just 176.65bhp while torque will fall from 84.3 to 82.6lb/ft. Crucially for the numbers-obsessed liter bike market, that gives the ZX-10R an inferior power-to-weight ratio not only to the BMW S1000RR, but also to the GSX-R1000 and MV Agusta F4.
The modifications to the North American bikes have been made in order to pass strict new EPA noise regulations and include exhaust and ECU changes. While the engines remain mechanically identical to their full-power European and Asian siblings, the bikes we’ll get have had their redlines reduced by 750rpm to 13,750 while the point at which the lower peak power number is delivered falls from 13,000 to 11,000rpm. Peak torque is also lower, now arriving at 11,000 instead of 11,500rpm.
This performance deficit has been verified by a third party source. As you can see in this video, Redline Motorsports in Calgary has scooped a first ride on a pre-production ’11 ZX-10R and even dyno’d it alongside a 2010 model and an S1000RR. Here’s the results on the same dyno on the same day. All the power outputs here are a little disappointing as Calgary sits 3,483 feet above sea level, but same dyno/same day means this is still an accurate comparison between bikes, even if it’s not an accurate representation of numbers that will be achieved at lower altitudes.
2011 Kawasaki ZX-10R: 159.8hp
2010 Kawasaki ZX-10R: 157.2hp
2010 BMW S1000RR: 168.1hp
The BMW S1000RR is officially rated at 193bhp (as all other official power numbers, that’s at the crank, dyno measurements are at the rear wheel), making it the current king of the liter bike hill. Weighing 204kg/450lbs fully fueled, that gives it a power to weight ratio (bhp/kg) of .95:1. As we saw in our 2011 liter bike numbers comparison, the un-restricted ’11 ZX-10R makes 197bhp and weighs 198kg (wet), giving it a staggering .99:1 ratio. In restricted American form, that number falls to .89:1, putting it behind the Suzuki GSX-R1000 and 2010 MV Agusta F4 too, on par with the Aprilia RSV4 and slightly ahead of the Yamaha R1 and Honda CBR1000RR. Assuming that, all other things being equal, power-to-weight is the simplest way to express straight-line performance, these numbers indicate that the new ZX-10R will be slower than than the S1000RR, GSX-R and F4.
Of course, with modifications to the North American bikes limited to exhaust and ECU changes, it should be relatively easy for owners to recover the lost power or achieve even more with the addition of an illegal can and race ECU. However, this does raise a larger issue. With sales of liter bikes largely pegged to whichever bike wins on-paper performance pissing contests and Kawasaki charging an ambitious $13,800 (equivalent to the base S1000RR, which doesn’t include traction control) the added cost of achieving equivalent performance could sway buyers in BMW’s direction. Perhaps tellingly, 2011 ZX-10Rs are already available for discounted prices; this dealer, for instance, is advertising $1,000 off the sticker price.