In terms of measured engine torque the 636 shows an advantage from just over 6000 revs. The torque curve broadens, surpassing the conventional 599cc engine’s peak at 9800 rpm, and continues to generate power through 11,400 rpm. Although the 636’s peak output is only 3.75 lb-ft more, the graph shows the mid-range advantage right where a rider needs it the most.
The previous iterations of Kawasaki’s 599cc Inline-Four always impressed on the dyno but the new mill reaches even loftier heights. The 2013 Ninja is the most powerful ZX-6R we’ve ever tested generating just north of 114 horsepower at 13,500 rpm. Compared to the short-stroke version it’s over seven peak ponies stronger, arriving 500 rpm earlier in the rpm range. Looking at the horsepower curve demonstrates the engine’s added brawn with it surpassing its prior output from as low as 6000 rpm.
Although priced atop the 600cc class, if you’re a performance maven it’s hard to argue against the added muscle without having to purchase engine hop-up parts or exhaust systems, thereby saving you some cash in the long run.