VW Beetle TDI Kammback

[SwamiSalami]

Originally Posted by markweatherill

There's something in that overall shape, I think.
See the Toyota Will Vi:

And this concept from Teijin:


These are 'closed' shapes so I wonder what the aero difference would be with a rear panel on yours?

Yea, I agree. There is something to the overall shape. It is a semi-kammback. Dr. Wunibald Kamm, aerodynamicist created the "Kamm" design in the 1930s. You should google it.

Yes, I do think a closed shape would be better. I'm working on this!

Thanks!

[Daox]

Originally Posted by dieselbeetle

So I guess what I mean is...with a scanguage, how do you know the moment is right to take a readout?

You set a specific route. That route should eliminate as many variables as possible. This usually means finding a quiet country road that has a decent speed limit.

Seriously, it is a good read:
http://ecomodder.com/forum/showthrea...ery-11445.html

[UFO]

dieselbeetle, that Kammback looks much better than I imagined it would. I've been so hung up on developing an Ernie Rogers wing, I'd not considered the Kammback.

Nice work!

[jedi_sol]

Originally Posted by Daox

You set a specific route. That route should eliminate as many variables as possible. This usually means finding a quiet country road that has a decent speed limit.

Seriously, it is a good read:
http://ecomodder.com/forum/showthrea...ery-11445.html

Even if there is a gradient in your route, you should do runs in both directions to average out the difference in the gradient.

[Piwoslaw]

Originally Posted by dieselbeetle

Spot the differences between the picture above and the one below:



Answer: The sides are angled inward at the same angle that the top is sloped down. The teardrop we are after is a three-dimensional shape, not just 2D.

When you work on the permanent version, try to get rid of the corners, like MetroMPG did:

[SwamiSalami]

Originally Posted by Piwoslaw

Spot the differences between the picture above and the one below:



Answer: The sides are angled inward at the same angle that the top is sloped down. The teardrop we are after is a three-dimensional shape, not just 2D.

When you work on the permanent version, try to get rid of the corners, like MetroMPG did:

I couldn't agree more, this would improve flow greatly. However, I ran into big problems because of the convex shape of the beetle's rear window. I'm mathematically perplexed.

[SwamiSalami]

Originally Posted by groar

Beware, it begins with only a test (mine was with cardboard) and a morning you find a chloroplast car in your driveway

You should consolidate the chloroplast as the gravity will make it bend.
This will be accentuated by fast speed for the top and side winds for the sides of your mod.
You should abuse strong tape and monitor it closely before the heat deteriorates it and so your mod flies away...

Does your mod always permits you to open your hatch ?
Please take a picture with the open hatch.

How much your mod reduces the rear view from the steering wheel ?
Please take a picture from inside.

Did you felt a difference under your right foot ?
I can definitively feel a difference with/without the rear wheel skirts, the car accelerates stronger and it's more difficult to keep it at a steady speed when the road isn't perfectly flat.

What about a rear wheel skirts test now ?

About the scangauge, I have 3 advices : buy it, buy it and buy it.

Have fun,

Denis.

I WAS able to open my hatch. However, I have removed my kammback until my next road trip. I'll photograph it then for ya!

I am very happy with the amount of rear visibility. I'd estimate the kammback reduced it by only 10-15% if any at all. A picture from the inside is a great idea. I'll do this as well on my next road trip.

I'll be driving to Texas from Orlando the first week in June. I'll definitely be enclosing my results and many new pictures.

[Bill in Houston]

Originally Posted by dieselbeetle

I'm mathematically perplexed.

Forget the math. Just get some cardboard and a marker and start cutting. Once you make one you like out of cardboard, then you can transfer it to acrylic or coroplast or shower surround or whatever you like.

[SwamiSalami]

That's a good point. What I'd really like, though, is to have someone design a kammback and 3d print it!

[jedi_sol]

Originally Posted by Bill in Houston

Forget the math. Just get some cardboard and a marker and start cutting. Once you make one you like out of cardboard, then you can transfer it to acrylic or coroplast or shower surround or whatever you like.

CAD = Cardboard Aided Design