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Old 07-21-2008, 07:20 PM   #8 (permalink)
Big Dave
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Join Date: Jan 2008
Location: Steppes of Central Indiana
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The Red Baron - '00 Ford F-350 XLT
90 day: 27.99 mpg (US)

Impala Phase Zero - '96 Chevrolet Impala SS
90 day: 21.03 mpg (US)
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It’s always a tradeoff between minimizing wake area and having an excessively steep slope. My bed cover does a nice job of minimizing wake area – a 47% wake area reduction – but does so at the price of having a seventeen degree slope.

It is time for me to revise my wake cover to make it handier to use. What I am thinking of is to reduce the slope to 11 degrees (1-in-5). This will mean my wake area reduction will be only 27%.

Going to a 1-in-4 slope (14 degrees) would result in a 37% reduction in wake area.

Does Hucho have a graph showing the effects of wake area reduction on drag?

I can’t do a full boattail. That would result in a thirteen foot long “tail” if one stuck to the one-in-five slope I’m planning. The truck is enough of a bear to park as is. The other extreme is simply a flush commercial cap. Zero degree angle but zero wake area reduction.
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2000 Ford F-350 SC 4x2 6 Speed Manual
4" Slam
3.08:1 gears and Gear Vendor Overdrive
Rubber Conveyor Belt Air Dam
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