speed

[ken medendorp]

took out the rr last night3/4 tank of fuel,2 220 lb guys and cooler 32 et turn8800 rpms...what kind of speed is that? no gps

[rock]

8800 x 32 x .0009469 x .5347 (assuming 1.87 gear ratio) = 143.57 x .9 = 128.31. This is with 10% slip. Running pretty good.
Rock

[ken medendorp]

cool
might have to try it agian

[HStream1]

I use a different formula but Rocks speeds calculate with mine.

Prop Dia X Engine RPM =
Ratio X 1056 =

So in your case as posted.

32 X 8800 = 281600
1.87 X 1056 = 1974.72

142.6 MPH - 10% slip = 128.34