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Old 12-06-2014 | 04:37 PM
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Default Low water pickup depth below bottom

DOES ANYONE HAVE EXPERIENCE WITH WHAT THE MINIMUM DEPTH YOU CAN GET AWAY WITH ON LOW WATER PICKUPS.

I have Latham Marine low water pickups mounted on the transom near the bottom of the V on a 30ft Sutphen with twin 502s. With the front edge flush with the bottom, the back is right at 1/2" deep and they are 2 1/4" wide. That's a lot of drag and probably a lot of pressure at 75mph. Previous owners have installed a 25psi water dump regulator and they start dumping right after planned off around 25mph.

Just to reduce drag I am going to grind the back edge off a little at a time until the 25psi regulators don't dump anymore. I have water pressure gauges connected after the water pump. Anyone played with this - that could add a mph or two. I have heard that some boats have them less than 1/8" deep and round the front edges to draw up the water better.

Also, what is adequate water pressure??? I would guess 10-15psi. Thanks.
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Old 12-06-2014 | 04:45 PM
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I plan on cutting water channel groves into the bottom of the hull feeding the pickups and allowing to raise them higher.
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Old 12-06-2014 | 04:47 PM
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3" below the bottom 92 mph I'm at 28psi
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Old 12-06-2014 | 04:49 PM
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The pickup @ 3" deep cost me 3mph but the motor doesn't get hot.
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Old 12-06-2014 | 05:08 PM
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you must have steps.

mine are almost level w/ the bottom of the boat,,maybe 1/8th" max.25-27psi of water pressure at 90+mph.
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Old 12-06-2014 | 05:09 PM
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Originally Posted by offshorexcursion
I plan on cutting water channel groves into the bottom of the hull feeding the pickups and allowing to raise them higher.
was told to do that by Ritchie Sutphen,said I may get alittle speed out of it.
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Old 12-06-2014 | 05:47 PM
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Originally Posted by sutphen 30
you must have steps.

mine are almost level w/ the bottom of the boat,,maybe 1/8th" max.25-27psi of water pressure at 90+mph.
On a flat bottom 1/4"-1/8" at the rear is normally enough.
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Old 12-06-2014 | 06:10 PM
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Latham has the depth built into them as long as the front edge is flush to the bottom that is where Latham says to install them. Cutting some grooves in the hull is a good idea. Latham creates the angle in the pickup. I just install the same one on my 26 sutphen and Lathams instructions said to mount front edge flush with bottom. Kind of wish I would have ground some channels now though.
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Old 12-06-2014 | 06:12 PM
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[ATTACH=CONFIG]533773[/ATTACH]Here's the on I just mounted, unfortunately I don't have any side angle pics.
Attached Thumbnails Low water pickup depth below bottom-image.jpg  
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Old 12-06-2014 | 08:22 PM
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My suggestion is to call Sutphen and see what their suggestion is to reach your goal.
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