back home...
well, the best for me, even for a daily is to get a flat bottom for the pan. this would extend forward under the head (1303 talking) and expand toward the sides of the car, leaving exposed the wheel wells and the control arm mounts on the head. at the back it should stop at the torsion bar housing, leaving the rear exposed.

the even more extreme solution would be to conseal the tranny as well (bottom) and sides, trying to form two wells for the rear wheels. In order to cool the tranny, i would use naca ducts starting at the torsion housing and blowing through two eclipses at the sides of the tranny box towards the axle mounts.although there will be a need for a means of cooling the bottom and getting access to the drain plug and fill plug of the tranny.

That's where differencies start, depending on rear tire size, offset and engine/exhaust configuration, the size of the rear wheel wells will have to vary for the rest of items to fit.

best would be to fabricate a diffuser at the back, keeping the tire and part of the suspension to the outside of each side of the car, tranny in the middle, but narrowing both diffuser paths (extending away from the centreline) for the engine/exhaust combo to fit.

Depending on the angle of the diffuser the fender/rear apron/fender combo will have to be chopped in order to for a bit of a proper profile for the 2 diffuser paths.

This only some idea, based on physics, NOT calculations. it also provides a means of "hiding" all enhancements from others, and not increasing drag the biggest aero prob of the bug imo is the rear, where we got an engine aft of a huge well ( where the tranny sits) and two wings that perform in a "parachute way" for the car

In the end it comes to the owner to decide which way and how far to go...

Chris

Just wanted to add this link for searches:

Bug Aerodynamics

Jason

Thanx Jason for posting the link here!

I made my own Roof Spoiler that's attached to the rear window rubber:
http://www.gerrelt.nl/roofspoiler/beta1.jpg

http://www.gerrelt.nl/roofspoiler/beta2.jpg

http://www.gerrelt.nl/roofspoiler/beta3.jpg

See this article on how I made it: Creating a Roof Spoiler.

That turned out great, that was my first choice as it is very subtle. I decided to go with the roof spoiler however because I fear that by that far back on a bug the lift is already quite considerable, the roof spoiler breaks up the laminar flow about 8 inches more toward the front.

How did you come up with the angle of the lip?

Jason

Thanks, Jason,

A guy who was into gliding (airplanes without engine), told me that everything above 12 degrees becomes an obstruction, while 12 degrees and lower is a deflector.

I don't know if it also applies to cars, but it turned out to be a nice angle.

Regarding roofspoiler placement:
I think a small roofspoiler further up front equals a bigger spoiler further back.
But it also depends on the speed you drive, the faster you go, the bigger the spoiler must be.
But I am no aerodynamics engineer... :)

Greetings,
Gerrelt.

Nice rear spoiler Gerrelt.
I also had the same idea as Gerrelt, but never finished it. It was slightly bigger with the same mounting concept.
http://i24.photobucket.com/albums/c4...2.jpg~original

Thanx Oldskool1303!

Yours would have been great too. It's got a more race-track look, more extreme.

If you could incorporate a third brake light would be something!

Yes! I thought about that, that would be excellent.

But.. I haven't found a nice way to get a wire to the inside of the car...
Maybe it could be led through the window rubber, but I don't really like that.
And drilling the glass is probably a big no-no... :cool:

Any ideas?

I really like this, it would probably work pretty well, especially for how unobtrusively mounted it is. It makes a lot of sense to me not to bolt through unless you have to.

Jason

nice... can we get some close up shots of it PLEASE... :)

Chris.

Gerrelt,

I too like your very discreet spoiler. Well done! One question - how did you fix it in position? Is it just held under the window rubber with some sticky pads on the end sections? My query there would be if there was any water ingress around the rubber as it will be stretched wider and the spoiler is not quite so smooth as the glass?

You have got to market this idea.

Clive

Hi Clive,

Thanx!

I've put some tape on the sides of the spoiler, on the inside. I didn't want to loose the spoiler after all that work. :lmao:
But it's held on pretty good by the window rubber alone. But, for assurance, a piece of tape or some sealant on the inside would be best.

I've been driving with the spoiler since June last year. I have driven through the rain, and I haven't seen a leak. The window is still resting on the rubber, making a good seal.

I have almost finished a mold. With this mold I plan to make more of these spoilers. Do you want me to inform you when they come available?

Greetings,
Gerrelt.

Hi Gerrelt,

It sounds as though its well proven then.
Please let me know when they become available either here or on my e-mail address - clive.williams@bwdltd.com

Many thanks:cheers:

Clive

Hi

I was driving my sons 1303 on a freeway today and I was thinking of this subject, is that weird?

Anyway I wondered what the affect would be on the "Parachute" area when you run a non air cooled motor, Subaru etc which has no sealing around the engine to body area, the otherwise trapped air would be able to escape through vents in the engine lid or the under rear window vents.

Steve

Interesting Thread! The vw bug has a Cd value of 0,48.A teardrop has 0,05 and an average aircraft wing profile has 0,08.The funny thing is a T2 vw bus has a cd value of 0,44 eventhough it has a larger surface area up front,it is much longer than the bug,which gives it an overall better value.
The bug´s aerodynamics are greatly improved by lowering the vehicle and adding spoilers as everyone knows.However,I haven´t seen any values to compare.
Some of the Käfer Cup bugs and a few of the hillclimb bugs have slots or holes in their fenders and some run shorter rear fenders allowing more air to pass out the back.If your racing,looks aren´t as important as function so I doubt that anyone is really going to adapt that to their street car.

I didn't realise a bus has a better cd :)

However cd is ratio thing so a brick has a cd of 1 regardless if it is the size of a Lego block or the size of a house. You multiply the cd and the frontal area to get the drag figure.

Rear Spoiler
 

Why don't you get one of these and make a mould of just the part you want.
It tucks under the window rubber.

I have one of those. I don't think it would help aerodynamically. Do you have a picture of the part that it mounts onto? (the part that actually tucks under the rubber). I'm missing that and it would be nice to see what it looked like :)

I think everyone's seen my aero by now, hard to miss...

http://i93.photobucket.com/albums/l4...5.jpg~original

Large vents in the front fenders seem to help a bit but I won't know for sure until I take it to a race track. The rear wing is almost necessary above 120, and can be felt as low as 50-60mph. I've also trimmed up the rear fenders to help them air out a bit as well. Currently I'm working on front aero which is not present and the bug understeers as a result. With the airdam and splitter in place the balance should be a lot better and I'll be able to dial in the rear wing properly.

For street use something above the rear window is best. A small strip like carbon joe did but a little bit taller, 2.5"-3" from drip rail to drip rail, would be ideal. Vents in the top of the front fenders might work for the street but I don't think they will be as effective, however they won't ruin the paint on your rear fenders.

A 1302 and 1303 seem to have a different characteristic than an older (pre -67)1200 bug.I rode with Armin Klein in his bug on the Autobahn here in Germany.We were doing 257Km/h (160mph) passing a Porsche Boxster S at full speed.He uses an inductive type digital speedometer.Even it may be 10Km/h off that´s still pretty quick.I didn´t notice any lifting or instability whatsoever.He has no spoilers whatsoever.He has a Remmele Uni-ball set up in the rear,the front is a standard lowered front beam.It´s a daily driver that he races regularly.Here are some vids of the car while racing.

http://www.myvideo.de/watch/6952465/...zburgring_2009 - open track day training in Salzburg

http://www.myvideo.de/watch/6952429/...g_Classic_2009 - race in Salzburg

http://www.myvideo.de/watch/5607224/...e_Leipzig_2008 - Porsche track day in Leipzig

www.turboboxer.de

And me. here is fine or a pm :) perhaps could combine on the international shipping?

Sorry haven't got the spoiler anymore, otherwise I would have taken some more photos for you.
I remember it being small pieces of z shaped metal with a hole drilled in it, then a plastic screw, screwed through the spoiler into the metal hanger, which was wedged under the rear window rubber seal... clear as mud I know

And me
Here is ok or pm me
Am also interested in combined international shipping?

I just put you guys on a list, once I finished a couple and know the price, I will inform you.:)

Thanks, I think I got the picture :) All I seem to be missing is the z-shaped metal pieces. I think I actually have the plastic screws too.

Hi

I owned flat screen bugs for years, Ovals, 40 hp bugs, late standard bugs & 1302s. Until a few years ago I had never owned a 1303 long term.

Seat of pants stuff, but the 1303 with its round front screen does feel much more slippery than a flat screen bug.

Steve

I haven´t been over 100mph in a 1303 yet,I never owned one either,so I lack the comparison. The 1303 does seem much quieter (wind noise) than the standard bugs,so there must be an aerodynamic improvement.Maybe the front of the 1303 has some disadvantage compared to the 1200 due to the round front valance? Technically the 1303 is far better than the standard bug,no question about that.

Lucky you said that here and not The Samba :lmao:

LOL!!! They will also tell you that the Cal-look rake is the best for aerodynamics!

found this... if you save it and voom in you can See the #'s

http://i41.photobucket.com/albums/e2...s.jpg~original

Chris.

That's one of the pages that came with a Kamei spoiler.

I've got that page and the rest of the pages here: Kamei spoiler documents

Sadly, the quality is not much better.

If somebody got these pages in better quality, please e-mail them to me!

Love it. Now to clean my screeen,as I did a spit take.

Nice tidy looking spoiler. Not sure if it is a one-off or comercially made as I can't read Dutch :)

http://www.keversite.nl/fotoalbum/fotos/107573.jpg

That's one I made :), here is a bigger picture of it:

http://www.gerrelt.nl/roofspoiler/spoilers/kever_Ed.jpg

And this is another one:

http://www.keversite.nl/fotoalbum/fotos/107065.jpg

And this is the one on my own beetle:

http://www.gerrelt.nl/images/phocaga...udel2010_1.jpg

I sold a couple in the Netherlands, and one in Belgium.
I am planning to ship them overseas too.

Does it slip under the seal or is it held on with double stick tape or something? I really like how subtle that is, was the shape designed with a specific angle or was that just the angle that was decided on visually?

Jason

There's a lip on it that slips under the seal. It's hold on pretty good with just that. But to be sure it won't fly off (and fly through the windshield of the car behind you..), you have to put a bit of sealant on the inside on the left and right. Just in de corner where the spoiler meets the window.

Here's a picture of two of them before installing:
http://www.keversite.nl/fotoalbum/fotos/107018.jpg

The angle is aproxametly 12 degrees compared the rear windshield.
I was told that anything above 12 degrees becomes an obstruction instead of an airflow guidance.

When are we going to see some more of these for sale! ;)

and when can you Ship over to Canada... ;)

Us Brits first! Then we'll allow some to float over.

Clive