Aerodynamics of a bug

[volkdent]

Hugo, you must be a brother from another mother. I've been looking for that crashed up New Beetle rear door for a while now, but nobody seems to be crashing them around here. My plan was to make a Lexan rear window that is the same as a normal one but the top 1/4 cut out, and place the New Beetle one in there instead. Let us know what you come up with!

Jason

[hugovw1976]

Originally Posted by volkdent

Hugo, you must be a brother from another mother. I've been looking for that crashed up New Beetle rear door for a while now, but nobody seems to be crashing them around here. My plan was to make a Lexan rear window that is the same as a normal one but the top 1/4 cut out, and place the New Beetle one in there instead. Let us know what you come up with!

Jason

Hi, bro.

[lazylongboarder]

On the way back from the airport in my 74' std. T1 with my best friend, the car had 28 year old shocks at the time, really worn out torsion bars/springs, down hill on the free way I got my bone stock beetle with 135's on the front and 195's in the rear not lowered to 98 MPH! If any one has gone that fast in a worn out stock VW it feels like 198 mph and 18,000 RPM, and it's rediculously fun and unsafe. Since then my beetle, first car, was a victim of a hit and run in a parking lot when I was not present and I was boo hooing like a school girl. So I decided to make my car so killer that NO ONE COULD TOUCH IT ! I'll show them! No but seriously, I had the Cal-look sickness at the time until I was introduced to the germanlook style in June 2002 by seeing the Bug-art T4 powered beetle in that months VWtrends issue, then I was cured. So some of you have seen VWCustoms "Project Pepper" which happens to be my brake setup; 6 pot calipers and 14" rotors front and rear from the front of the crazy fast Cayenne turbo which according to Porsche "stops the 7700 lbs. vehicle with a 7800 lbs. trailered load (without brakes) from 80 mph without a hint of fade". With that said I think that my beetle should'nt have a problem stopping with similar hp (450) figures. Also, the Cayenne Turbo has 4 pot 12.8" brakes out back.

[ericglooker]

[QUOTE=chigger]
"A rear spoiler is a necessity also to break the rear lift. It doesn't have to be very big. The angle is important. It and the underbody difusers output should create a defined flow much like using sheet metal. If drawn it would look like a pointed tail coming off the rear of the car. The spoiler can also be used to pump a wing. In order to work properly the wing must be positioned over the ground with no car parts under it and as low as possible. This would look quite weird and work very well, maybe to well as it might lift the front end. Raising the wing until the airflow from the spoiler flows below the wing would pump the wing and perhaps create the same effect."

What if you replaced the rear bumper with a spoiler this way it would use the air comming over top of the car and also the air from under the car. and not only would it work well and wouldnt look retarted and ricer like those huge wings do. (my 2 cents)

[bow]

i say put a scoop under the car and make it an air conditioner and it would spoil the air under the car also look for pic's of the under part of lambo's

[rip]

Originally Posted by jimby

its easy to plug some numbers into a spreadsheet ive got

i need the frontal area of a bug in Metres squared
the Cd (aerodynamic drag cooeficient of a bug)
mass
gear ratios
horsepower
Centre of gravity height
rear wheel radius
maximum rpm

jimby was wondering if you wouldn't mind giving me a copy of this spreadsheet? I'd like to see how it works.

Thanks
Rip

[Uber Affe]

Originally Posted by bow

i say put a scoop under the car and make it an air conditioner and it would spoil the air under the car also look for pic's of the under part of lambo's

That sounds great in theory, but I had a leak in the seam of my right front floor panel that used to leak and gurgle water like a babling brook when I hiy a puddle and it was quite high off the ground as y suspension was stock.
I'ts raining cats and dogs right now and I guarantee the H2O would fill up like a jet in a jacuzzi w/ an intake underneath...EVEN with some kinda trap on it.

[bow]

put a flap to release the water on days it is raining

[thelazerviking]

thelazerviking Research and Design team presents...






tada.


no fancy spoilers venturis diffusers wahtever the hell.

instead of your fenders being restrictive they can be used for downforce.

....and a duct to cool the brakes off and help air flow can also be incorporated into the green area.

you can reverse the whole thing for the back of the front fender to create better airflow and vent out that fender too indstead of those louver ideas and junk tghat probably won't work so well



stop trying so hard.

[LOAF]

Lazer..

Where in NJ are you.. it is great to know that there is someone else from NJ..

Alex

[beetle1303]

something I was thinking of doing is shown in the pics below. I know the pics are from a 911 rsr, but the basic idea is the same. In order to take things to the next level I would like to have an inner fender, as the cars have positioned in front of the wheel (looking the car from below). This would minimize air turbulance above the fake bottom in front of wheel

Any comments are welcome

Chris

[beetle1303]

Originally Posted by thelazerviking

you can reverse the whole thing for the back of the front fender to create better airflow and vent out that fender too indstead of those louver ideas and junk tghat probably won't work so well

I was thinking of making the front wings as the 935 K3 car. Flat on top following the curve of the front (side view) merging to the front quarter panels (where the 1303 has the fat trim piece) and being open (view from the back)

Chris

[thelazerviking]

the bug is like a giant airfoil, especially with it's flat bottom. put a front spoiler on it and lower the car then instead of high pressure under the car it should be a lower pressure. i think the reason the rear end feels so light at high speeds is because of how rounded out the back end it, there's probably a very great area of low pressure there, pulling the rear end up. if the front is lower than the rear that should help keep the rear end down too because it creates low pressure in the rear of the car, that's basically what a spoiler does though. check out how airplane winds work with airfoils.

[bean_8044]

this reminds me of something i was working on in Japan.
http://www.asahi-net.or.jp/~ge8w-ngk.../mente272.html
Its in japanese, but you can see the schematics which is all you really need. No, that wasnt my car, but i was trying to make it work on mine

[PJL54Oval]

HotRod Magazine just did an article on this subject. Some simple things to do are the front air dam, Lower the front of the car sightly more than the rear (accelerates the air under the car), Add side skirts to prevent air from entering the bottom from the sides and Spoil the air off the back of the car. Spoiling the air actually accomplishes two things. It decreases lift especialy with the shape of the beetle and also reduces drag by eliminating the low pressure at the back of the car.

Now on a completely different line of thought, has anyone here ever seen the Chaparral 2J? It was nick named the "sucker car" and had two fans mounted on the back of the car to literally suck the air from under the car. If you are running an air cooled engine you could draw some of the air from under the car (like some of you do) and this actually helps! Here's a link that shows the two snowmobile engine driven fans on the 2J car. http://www.petroleummuseum.org/Chaparral/Tour4Indy.html

I doubt that this will help us much but it was really cool to see.

Jim Hall was a pioneer in Ground effects and dominated road racing. He won indy his first year (Johnny Rutherford driving) by channeling the air under the car to create down force.