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Conventional V-bottom hydronamics question..........

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Old 12-24-2007, 10:44 AM
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a good analogy is pouring a little water on a waxed tile floor then droping a waxed tile shiny side down on top of the water . then trying to pick it up. wont be easy. flip the tile to the un finished satin side and it lifts .
same method or theory when wet sanding the bottom fore to aft.
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Old 12-24-2007, 10:55 AM
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montassa,

Your right with that and I guess it's relative to the size of the dimples. The porus side lifts easier because the contact patch is so much smaller than the smooth side.

I think the dynamics change when water is passing by something at 80 mph as compared to being static?

Only one way to tell make yourself a little test bed and video tape it, I don't know what will happen - maybe it works?

Debating a tech issue as you know only goes so far, you have make it and test it to get real data whether it is virtual or physical testing.
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Old 12-24-2007, 11:13 AM
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What are the thoughts on how I high I an go with lower units with the notched transom. Will their be adequate water pressure for motors if I raise loweres so bullets are in line with notched transom?? And I know I will lose a lot of bow lift, I guess all trial an error
My first question is how fast is the package going to go? If you only go around 65mph, keep the motors low. Gains from reduced drag of high motor position won't show up until your around 75-80 +. If your going slower than that with a high motor setting, you will lose percentage slip and the ability to carry the bow with trim. That could make you slower.
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Old 12-24-2007, 11:22 AM
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all good points, the aeration would come from forward momentum, and waves...they are the constant...Bo, in your tile theory you are correct, if you left it flat side down, they only way to remove it would be to wiggle/aerate the tile with movement, then pick it up.
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Old 12-24-2007, 12:10 PM
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Originally Posted by Knot 4 Me View Post
Every F-4 is a 38PP...albeit in highly modified form!! It was a great basis for a great hull.


I agree..the 38 PP is an awesome riding hull. The 43 Sunsation, with the added proper step placement, araited, and with the GRAPHITE applied on the bottom to help reduce drag is an excellent riding boat and gives also one of the best rides in rough water that I've been on. Kudo's to Sunsation. Whom ever did the engineering on that hull did an excellent job, I call it like it is.
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Old 12-24-2007, 04:55 PM
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Originally Posted by mccaffertee View Post
OK, but with this same example, would the tile (shiny side down) slide across the floor easier and quicker than the rough side down?
great,,,,,,,,,,,, now i have to wait for the egg nog to ware off and start spillin stuff on my wifes floor,,,
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Old 12-24-2007, 04:58 PM
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Originally Posted by HabanaJoe View Post
montassa,

Your right with that and I guess it's relative to the size of the dimples. The porus side lifts easier because the contact patch is so much smaller than the smooth side.

I think the dynamics change when water is passing by something at 80 mph as compared to being static?

Only one way to tell make yourself a little test bed and video tape it, I don't know what will happen - maybe it works?

Debating a tech issue as you know only goes so far, you have make it and test it to get real data whether it is virtual or physical testing.

i have tried this theory, and it is good for 1 to 1.5 after the 85 mark. so in these cases it did work. i do agree about trying every theory before commenting on it directly.
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Old 12-26-2007, 02:30 PM
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Originally Posted by monstaaa View Post
i have tried this theory, and it is good for 1 to 1.5 after the 85 mark. so in these cases it did work. i do agree about trying every theory before commenting on it directly.
Good point.
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Old 12-30-2007, 01:19 AM
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The dimples on a golf ball move the seperation point of the air from the ball, reducing turbulence and thus drag.


This was not discovered by scientists, but, by players noticing that their well dented gutta percha golf balls traveled farther.

I don't think it will work on a boat hull bottom.
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Old 12-30-2007, 07:58 AM
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surf boards have used dimples for speed for a few years now.

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