This dyno chart shows the difference between a stock, North American 2011 Kawasaki ZX-10R and one that’s had its ECU told to stop restricting throttle openings at high RPM. Both measurements include the same slip-on exhaust canister. Courtesy of Speed Tech Motorsports, this dyno chart is the best illustration we’ve yet seen of the effects caused by Kawasaki’s attempt to meet EPA noise regulations. Stock ZX10-Rs for other markets are rated at 197bhp (at the crank), while North American bikes are rated at 176bhp.
Speed Tech reports that, on it’s relatively conservative Dynojet, the completely stock bike was putting out 164hp at the rear wheel. To achieve 180hp, they fitted a Hindle slip-on and modified the stock ECU program to allow full power past 11,500rpm. In this configuration, they say the engine is still running lean and expect even better results with the fitment of a Power Commander.
It’s been officially stated that Kawasaki made changes to the exhaust can and ECU on North American bikes in order to meet the EPA noise regulations. They’re not the first manufacturer to be forced to do so, but it does appear as if the ZX-10R has had its power reduced the most dramatically. Changes, by all accounts, are not made to the engine itself, meaning obtaining full power is relatively easy, as demonstrated here.