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Speed / Hp ?

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Old 02-03-2003, 02:16 PM
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Default Speed / Hp ?

I can't find the sit that had the speed/ horsepwer/ hull drag coeficient(sp) equation. can anybody shoot me the link
Thanks in advance.
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Old 02-03-2003, 02:21 PM
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go-fast.com
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Old 02-03-2003, 02:23 PM
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thanks man.
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Old 02-03-2003, 02:29 PM
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http://www.go-fast.com/boat_speed_predictions.htm
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Old 02-03-2003, 02:42 PM
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JUST ONCE,

A simple equation that I believe will get you close is:

New Speed = Old Speed times [ the squareroot of (New HP / Old HP) ]

or

New HP = Old HP times [ (New Speed / Old Speed) squared ]

Some people say that it should say "cubed" instead of "squared" but "squared" and "square root" will get you close.

Do the math!
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Old 02-03-2003, 02:59 PM
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Clay, thats pretty cool seems close!
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Old 02-03-2003, 03:11 PM
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Calculating for that new blower
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Old 02-03-2003, 06:04 PM
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Could be either something is wrong with the data, or that particular hull needs a different constant. The constants are not fixed in stone, but determined from experience with similar boats.

Picture changing to a Sportmaster or Labbed prop or something else that gives you 5-10 MPH with no change in weight or power, the constant will be different.

The best use of the calculator is to input the known weight, speed and power, then calculate a constant for that hull set up.
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