I finally broke 55 mph in my racing flat bottom. I bought a mercury chopper 2 18 p and this prop is amazing. I know you guys think i might be crazy but my motor is to low in the water for running a chopper. My prop shaft is 2 and a half inches below the bottom of the boat and i still have some rpms to play with before i hit my rev limiter. How much more speed can i expect if i continue to raise my motor??