A look at the torque curve will explain what's going on inside the ZRX's mill; peak torque of 71.5 foot-pounds occurs at just 5750 rpm. The ZX-11 (which the ZRX engine is based on) makes only slightly more torque, but with bigger carburetors, different cams and more compression, it does so at higher rpm to give it 131 horsepower-35 more than the ZRX. If we could move the ZRX's curve up in the rev range to be more like the ZX-11's, its power would go up accordingly. It may not reach the peak levels of the 11, but if the green bike could hold, say 60 foot-pounds of torque to 10,000 rpm, that would work out to about 115 horsepower. And that is nothing to sneeze at.