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Thread: Polar Bear 2018 Video
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03-12-2019, 10:20 AM #91
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03-12-2019, 10:32 AM #92Senior Member
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03-12-2019, 10:50 AM #93
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03-12-2019, 11:00 AM #94Senior Member
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Polar Bear 2018 Video
Last edited by dakota4ce; 03-12-2019 at 11:02 AM.
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03-12-2019, 11:34 AM #95
At a very simplified representation there are planning hulls and displacement hulls. Then you start taking sections through an actual hull port to starboard, bow to stern, keel to water line and looking at how that shape transitions and how the waterline changes with speed. Now you start getting into that CFD. You want to engage different shapes at different speeds to produce different results at different speeds. Initial lift at slow speeds, less lift at desired speed etc. Why shape a hull that fights your desired end result? Most wakeboats were already headed the right direction anyway but some have optimized for surfing better than other thus requiring less offset weight.
I guess all those fluids and aerodynamics classes I took are holding me back in the physics department.
You are looking at displacement in only a static situation. When the boat is sitting still overall weight of the boat + ballast will displace = weight in water. When you start moving all that changes.
I’m not arguing that a Makai needs more weight than a FI to achieve the same results. I think in fact that’s the point. One manufacture is set with killer wave from factory no need to 2-3k in lead and ones not.'06 Outback - Gone but not forgotten
'13 Mojo
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03-12-2019, 11:40 AM #96
I'm not sure I understand "equal". Are you saying boat weight + ballast weight for each boat should be the same? That's not "equal". You add weight to the SE to get total weight the same as the RI257 you aren't equal because now you could add 2K to the RI and make it better.....
'06 Outback - Gone but not forgotten
'13 Mojo
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03-12-2019, 11:47 AM #97Senior Member
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Except how do you explain that if you give the Makai the same amount of weight as the FI it makes a very similar size and awesome wave? It really doesn’t need “more” than the Fi.
If you close that 1200 pound gap between the Polar Bear Fi and Makai, the waves are very similar. I have run mine at that weight. It’s ridiculous.
But....That shouldn’t happen with their hull designs being so different—right? Or maybe their differences simply don’t matter a lot in this situation and at these speeds. And overall displacement really isn’t the most important factor. It’s really about the depth of the hull in the water at weight and speed. And it’s ability to stay down. Nobody is really planing at surf speeds.
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03-12-2019, 11:50 AM #98Senior Member
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Equal overall weight in order to sink the boat to similar depths.
The Ri comes with a LOT MORE stock water ballast than SE.
Yes you could add more to the Ri if you want. If you can get the motor to actually push it. You’re going to run into the limit of a single propeller to be able to push it.
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03-12-2019, 11:53 AM #99Senior Member
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03-12-2019, 11:56 AM #100