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Old 06-30-2016, 12:42 PM   #11 (permalink)
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Quote:
Originally Posted by mikesheiman View Post
So I'm guessing 10-12 degrees is the suggested angle range for any and all tapers in the back (essentially along straight lines inward)?
The 10-12 degrees applies to flat surfaces (fastbacks), and yes they are easier to build than the curve of the forum's aero-template.

If you can pull off a 3D curved surface, go for it. Many people have done it, more than one way to get there too.

EDIT:...................................

I think the upward slope of the body and floor is half of the top's decline angle.

I did not draw a five degree slope up for the bottom of the tail, should be there though for driveway clearance if nothing else.

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Last edited by kach22i; 06-30-2016 at 01:23 PM..
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Old 06-30-2016, 12:52 PM   #12 (permalink)
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Would appreciate elevation pics; front, sides, rear and top. Maybe a bottom pic to see your belly pan flow. Intakes, cooling and exhaust considerations too.
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Old 06-30-2016, 01:26 PM   #13 (permalink)
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Quote:
Originally Posted by kach22i View Post
Aerodynamics by George Kachadoorian | Photobucket


A picture is worth a thousand words?

I included Frank's in-fill comment for the front wheel, that of course would be a rounded edge, just showing the concept here.

As originally presented, looks like one of those designs which would perform better backwards - sorry.
George, I think you nailed it.

Mike, question about the "shoulder" at the back of the sides - the area where George's sketched fill meets the suggested taper: is there something under there?

If the fill could continue down and in (rather than the "shoulder"), then it would be even better.
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Last edited by NeilBlanchard; 06-30-2016 at 01:32 PM..
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Old 06-30-2016, 03:04 PM   #14 (permalink)
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Ya know, I think we can be much more aggressive with our retreating angles of attack.

I recall discussing the latest Porsche 911 a few years ago, compared to my own vintage air-cooled model.. The old cars were about 27 degrees on the rear window, the liquid cooled ones of late are 20-22 degrees.

These are some of the lowest Cd cars on the market, many wind-tunnel images show attachment.

Be bold.

The 10-12 degree angle are for flat roofs like 1971 Ford Mustang Mach-1.

You have curves, curves love air and vice versa.

Aerodynamics by George Kachadoorian | Photobucket


EDIT: I'm old and my memory sucks, looks like 16-17 degrees, but you get the idea, right?

I at least got my own car right.


http://s184.photobucket.com/user/kac...?sort=3&page=1


When you have time, check out this thread - long but good.

How To Line Up Template - Sports Car Design

And another good thread:
Kammback Angle Okay?
Quote:
Originally Posted by kach22i View Post
It's less than 22 degrees, gradual incline and generously rounded corners.

Looks good to me.
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Last edited by kach22i; 06-30-2016 at 03:13 PM..
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Old 06-30-2016, 05:15 PM   #15 (permalink)
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Just having fun...
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Old 06-30-2016, 05:46 PM   #16 (permalink)
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Just having fun...
That puts me out of a job.

Gosh that's nice.

Reminds of these:
The World's Most Fuel Efficient Car: 285 MPG, Not A Hybrid - Gas 2


Volkswagen XL1 Car Price in India, High Mileage Car
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Old 07-01-2016, 12:50 PM   #17 (permalink)
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This is a trike, so the side taper can be more aggressive.
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Old 07-01-2016, 01:19 PM   #18 (permalink)
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Quote:
Originally Posted by NeilBlanchard View Post
This is a trike, so the side taper can be more aggressive.
...totally different final shape then. Might need a 'naked' pic to see his hidden mechanicals, the pic looked like it had covered rear wheels
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Old 07-01-2016, 02:33 PM   #19 (permalink)
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Yes, a 5:1 airfoil is 5x as long as its widest dimension. A 75% Kamm truncates the tail at 0.75 x the full length. A vehicle that is a maximum of 50" wide would be 250" long then shorted to 250" x 0.75 or 187.5" (15' 7.5"). You have some good sketches to consider. Something like a Mercedes C-111 or Lola T-210 front and a tail from the Riley XR3.
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Old 07-01-2016, 03:34 PM   #20 (permalink)
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Quote:
Originally Posted by NeilBlanchard View Post
This is a trike, so the side taper can be more aggressive.
I'm not so sure about that.

Read this a couple of times.

Quote:
Originally Posted by mikesheiman View Post
And, agreed, it does look like it would perform better backward, but then how would/could I make it stable as a 3 wheeled vehicle and have enough headroom for the rear passengers? Not asking that as a rhetorical question...I may well (if only quite eventually) remake the car in such a body style eventually if it's possible.
The front does look more narrow than the rear, but I don't think it's a trike.

Hopefully mikesheiman; will chime in and provide the requested information.

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