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Old 06-17-2013, 10:14 AM   #31 (permalink)
kach22i
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Quote:
Originally Posted by Xist View Post
Nice post.

Quote:
Originally Posted by aerohead View Post
*My boat tail was also 20-degrees in 1980,with a length equal to 75% of body height,bending gently into the slope......
If we take a car of approximately 4.5 feet in height, the boat-tail would be 3 Ft 4-1/2" long, right?

The 75% of body height, that's a scaling factor, right?

In effect, we can scale down the template 70-75% (range listed) and get 97% (31/32x100) of it's benefits, right?

Why don't we just scale down the template then?

Is there a chart showing the losses when scaling down?

Say for instance:

X.100/100% (1:1)

X.75/97%

X.50/39%? (just a guess)


It's that last ratio I'm interested in most. (see edited comments far below)

If I had at least three reference points I could start to chart this scaling relationship of L to H and percent of boattail affect.

EDIT-1:
Automobile 2 - Odds And Ends Photos by kach22i | Photobucket




EDIT COMMENTS:
Scaling down the template for "boattailing purposes" by a factor of 75% to get it to 1/4th of it's original size results in getting 31 mpg in lieu of 32 mpg on a Dryden/NASA style van, right?

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Last edited by kach22i; 06-17-2013 at 10:57 AM..
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