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Old 13-08-2006, 03:56 PM   #1
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Anyone know the calculation

For working out your estimated speed using your prop pitch,gear ratio and engine rpm?
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Old 13-08-2006, 04:15 PM   #2
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Country: United kingdom
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Boat name: S.B Racing
Boat make: Ocke mannerfelt canopied B23 / Zapcat
Engines: Merc 200XS Gen 2 / Tohatsu 50
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Got it now cheers guys!
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Old 13-08-2006, 05:06 PM   #3
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Go on then, what is it?
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Old 13-08-2006, 05:47 PM   #4
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Boat make: Bernico F1 Twin, Monterey 265SC.
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Engine RPM divided by gear ratio times prop. pitch divided by 12 (inches in a foot) divided by 5280 (feet in a mile) times 60 = Optimum Possible Top Speed (100%). 87-89% is very good. This is from Powerboat Magazine - believe it if you will.
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Old 13-08-2006, 07:29 PM   #5
1up
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or go here and go to bottom of screen on to prop slip calculator and enter you pitch gear ratio and rpm and click calculate under speed and it will tell you your speed

http://www.mercuryracing.com/products/propellers/
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Old 14-08-2006, 12:15 AM   #6
Ben
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A slightly easier way to determine theoretical top speed is max revs X pitch/gear ratio X .00094976.
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