1986 Jetta Carbonfiber whaletail

[Sven7]

Looking good. If you can, make the edge radius grow larger as it goes back. This will allow pressure differences on side or top of the car to dissipate before they leave the body, reducing vortexes and drag.

PS- Merkur was not a Mercury- it was simply a brand Ford of Europe made up in order to sell their cars here.

Also, your camo Windstar is awesome!

[Varn]

Just got my first layer sanded a bit. I don't like to sand down so that more than 30-40% of the under layer shows. I wet sand to prevent breathing the crap.



There is distortion in this photo making it look bigger than it really is.

I intuitively agree that the rounded shape is best. Then I looked carefully at the Prius. They made the top distinctly at right angles to the sides. And it seems to work. The Jetta is as square as the Prius. I just thought that I would carry it out at the ends. I could always end up with a complete tail keeping this top wing as a starting point.

[Varn]

Did some tuft testing this morning. 16" behind the fairing I was getting smooth flow 9" above the trunk lid there was turbulent flow below 9". I used some 1/4" dia wire and hung yarn at various heights. I moved the tree back to 25" and the yarn was spinning around at 13" above the trunk lid. Obviously the effect of my roof extension doesn't extend too far back something between 16 and 25 inches.

Here is the tuft test at 16" behind the edge of the fairing.
The top and second yarns are flowing back the lower two are all over

[aerohead]

Originally Posted by Sven7

I assume you mean the Merkur XR4Ti which wears what is essentially a Ford Sierra Cosworth spoiler.



Not sure it'll give you much gain, if any, but it'll be interesting to see.

The spoiler is derived from Ford's Probe III concept car of 1983.This bi-wing spoiler received a U.S.Patent in 1982 and Germany in 1981.
On the Probe,the top wing of this 'Flow-Stepped Tail' helped alter the aft-body departure angle from 26.5-degrees,to 18-degrees, helping the car achieve Cd 0.22.
On the Sierra XR4 the wing dropped the Cd by 0.02.
For the Jetta it should do a bit better,as it is a more 'significant' enhancement.

[BamZipPow]

What are the chances of finding the actual spoiler and adapting it to yer car?

Car-Part.com--Used Auto Parts Market comes to mind...

[Varn]

Here is what I came up with. If it passes the test I plan on layering it with carbon, then popping the finished parts off digging out the foam and reattaching them to the body.

Bampow. Do you mean like "purchase" a premade lip.... Now go clear your mind of such words like "purchase" .

[aerohead]

What you're doing is what might have happened with the Mercedes-Benz 190 EVO,with diminutive backlight spoiler combined with raised trunklid spoiler.
'will be interesting to 'see' the numbers your combo produces.
Thanks for the 'sweat!'

[euromodder]

Originally Posted by Varn

Did some tuft testing this morning. 16" behind the fairing I was getting smooth flow 9" above the trunk lid there was turbulent flow below 9".

Well, that settles the height of the wing then.

You could angle the vertical supports of the wing inwards (narrower towards the back - say 15-20° ) as they will be hit by air spilling over from the sides

[Weather Spotter]

looks good, keep up the good work

[mcrews]

are you going to mold them on or use attaching points?