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Old 07-26-2015, 02:03 PM   #11 (permalink)
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Lift the hatch to the correct angle and take a picture. Measure the added overall length. Decide whether you can live with the added length; else consider a Kamm-back. The closed hatch probably stiffens the back of the body.

The gap would need to fill all four sides, so you'd open the hatch, insert your filler and close the hatch on it. Any gap will infiltrate dust and exhaust gases because of the pressure differential.

A slant roof chop could help, but lowering the back changes the bottom of the car, too; increasing front end lift. Best to be level or slightly down in front.

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Old 07-26-2015, 04:33 PM   #12 (permalink)
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The closed hatch also definitely attenuates noise.

Didn't someone on here do this? I do not remember enough to do a search. He had an 80s fast back or something...
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Old 07-27-2015, 03:04 AM   #13 (permalink)
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Old 07-27-2015, 03:05 AM   #14 (permalink)
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please forgive the advertisment sticker on the side of the car
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Old 07-27-2015, 05:23 AM   #15 (permalink)
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Your car is shaped a lot like my old Festiva, Black Widow. If you're interested in wheel skirts, I'm sure my DYI is still on here.

Adding a front grill block, rear wheel skirts and a Kammback (along with changing driver habits and routes, and a lot of P&G) gained me a lot of mpg back in the day. I went from 42 mpg to the high fifties, and broke 60 mpg one tank.
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Old 07-27-2015, 02:28 PM   #16 (permalink)
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http://ecomodder.com/forum/showthrea...ion-21952.html

You can confirm the angle of the hatch with the Template Tool. It looks to me like it should be opened a little more. At that point the bottom of the hatch blocks the view in your rear view mirror. I'm not sure what to do about that.

It looks like the hatch could be opened all the way and then closed on a rubber rod or tube to seal the top. The triangular side pieces should be flushed to the contour of the C-pillar. The bottom could be a tub to increase the size of the boot, or a subwoofer box if you have a sound system. It needs to extend to a difusser at the bottom for maximum result.
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Old 07-27-2015, 02:55 PM   #17 (permalink)
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Hey Arklan,

Welcome.

Get down to a lower angle when you take your side photo of the car - and back up. Use a telelphoto setting on your camera or zoom in, line yourself up with about the middle of the car's length and have the camera's lens level with the roof of the car. You want as undistorted an image as possible.

Then you can take that photo and superimpose the template onto it and see how much you need to raise the hatch. I think the hatch with an added section of bodywork under it to fill the gap is a good way to go. It makes use of mostly materials that are already on the car. Can't fault that.

Cowmeat's suggestion of a grille block and fender skirts are spot on. That little car has no power to spare, I'm sure. Doing anything to reduce the load on it when cruising is going to pay dividends.
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Old 08-03-2015, 08:26 PM   #18 (permalink)
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Filling the dark blue area behind the car with boat tail makes this drag go away.
[/QUOTE]

I assume this theory would work for say an suv such a 4runner
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Old 08-03-2015, 10:09 PM   #19 (permalink)
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Quote:
Originally Posted by Xist View Post
The closed hatch also definitely attenuates noise.

Didn't someone on here do this? I do not remember enough to do a search. He had an 80s fast back or something...
I looked into it for testing purposes on the beetle, but the hatch tapers wider, so it would be a bit like superman's cape. Not exactly a streamlining maneuver.
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Old 08-05-2015, 04:39 PM   #20 (permalink)
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suv

Quote:
Originally Posted by Asanelli View Post
Filling the dark blue area behind the car with boat tail makes this drag go away.
I assume this theory would work for say an suv such a 4runner[/QUOTE]

This tail was tested on a 2012 GM SUV model,both in the wind tunnel and CFD.
It provided a 26% drag reduction,or +14% mpg HWY.

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