Aeromodability of a VW Bug?

[gtkid2002]

Ahah! Speaking of Fluid Dynamics!! I found an awesome link, did some reading, made a bitmap image, and posted the video to youtube. What do you all think?

http://www.youtube.com/watch?v=5BUdkAvgyXo

Granted it is VERY ROUGH, it took me all of a minute in MS Paint, and there are no wheels touching the ground. Hopefully will be the center of the car?

[botsapper]

Those are some nice images, but would require some uber fabrication skills to build one like that.[/QUOTE]

...there are some uber fabricators out there...
http://farm4.static.flickr.com/3532/...2d4dddb707.jpg
http://farm6.static.flickr.com/5004/...f51f685959.jpg
http://1.bp.blogspot.com/_FoXyvaPSnV...-Cabrio-18.JPG
http://www.slipperybrick.com/wp-cont...-vancake_1.jpg

[123]

There are defiantly some people with lots of fabrication skills but those are much simper then the aero version. After seeing those first pictures you posted botsapper I wish I still had the rusty westfalia I parted out, would get out the welder and start building.

[euromodder]

Originally Posted by gtkid2002

On the bit about the fenders, here's a different sketch of what I'm trying to go for.

Looks good.

The ground clearance seems unrealistically small though.

[gtkid2002]

Yeah. I'm not sure if I should allow compensation for if I hit a speedbump or if I hit a pothole, as stupid as that sounds. I'm thinking of this thing for being used only for highway and some mild city use, so the suspension wouldn't be being used much.

Although it would be kinda cool to have it be fiberglass or something till the last four to six inches between the body and the road, and extend it down to about two inches or so of easily replaceable chloroplast or something for makeshift wheel pants (I really didn't know that's what they were called. Kind of a silly name, but it fits!). Or cardboard so it's recyclable, and if it does scrape off, it'll be a bit more biodegradeable than a Styrofoam cup, haha. I guess I have to keep in mind that I will use a socket wrench for a hammer now and then. Probably should design the car for higher clearances so it doesn't get the belly pan raped every time I take it up a steep driveway.

I know my skillz aren't anywhere near the caliber of some of the stuff Botsapper posted, but they should be enough to make a roll cage with a skin. That's basically all I'm doing.

Although I still have no clue how the crap I'm going to make doors. That is the only thing that concerns me. I should be keeping the original VW doors, so I could always repurpose those hinges or maybe even a good portion of the door. Make it so it uses the stock window, but chop the top part so it only goes halfway up or something.

Another thing has me wondering - Could I get away with using Plexi for the windows on this, or does it -have- to be safety glass? If I can use Plexi, I will for as much as I can, but if I must use the original windows, then chances are this thing will have funny looking windows.

I was playing with that online fluid program a bit more, and I ended up making a design that didn't seem to do too badly. It kinda looks like a messed up ice cream cone. Here's a link.

http://www.youtube.com/watch?v=JNGLx2G6SN0

I know the aerodynamics are different, but I figure if rockets can use pointy nose cones, why can't I, at least for testing?

Another thing - That Aerodynamic template reminded me of a Deer Hoof. Just one side of it. Randomness Achieved.

[Pendragon]

gtkid2002,

botsapper's drawing has many compound curves which would be a challenge for most anyone's fabrication skills. (Can you say 'panel beaters'?) The pix he posted show the work of some very talented people, but their work was nowhere as complicated as I believe this would be.

As to the suspension, this is just my opinion, but I would be very concerned about taking any vehicle on the road which did not have a suspension capable of dealing with a pothole or bridge transition given the state of our roads, bridges and highways these days.... I have seen lowriders bounce uncontrollably when in their lowest position on the road. It was pretty scary, but that is just my opinion. It will be you who is in the vehicle to deal with the problem.

Cheers

[skyl4rk]

http://www.youtube.com/watch?v=9XUKOUbp_PA

[nimblemotors]

Exactly. My opinion is that a VW bug would do very well if you reversed it, where the front as the back and the back was the front, much better aerodynamically. This racer is even more so, just as I'd make it in reverse, swoop the back together like that, and have the front chopped, and whole car narrowed. It would be quite a car.
I would make it an EV.
It would be a huge amount of work.

Originally Posted by euromodder

This looks like one of those cars that would do better going rearwards

[gtkid2002]

I wonder if I can get tires like in the video that skyl4rk posted and use them legally nowadays...

Nimblemotors - I would try and do something like that, but I don't really want to play with the original body. Considering for starters I'm just having a roll cage and a wire mesh/fiberglass skin to start with, that seems like a ton of work. I would consider doing an EV, but the kits for those are uhh.. pricey. I know doing an engine swap is as well, but I also would really be stuck at home with that because of a lack of charging stations.

Heh. But the concept of driving a backwards VW Bug does sound really amusing.

Pendragon - I'm going to leave the stock suspension in place, I was just thinking about leaving the body (at least some of it that would be easily replaceable) in areas that could get damaged so I could streamline a bit further. Although that just got me thinking. It would be a pain, but make individual wheel pants for the front wheels, and still have them enclosed by the main body (with access hatch of course) so that way the wheel pants would bounce with the tires and not be damaged.

[aerohead]

Originally Posted by gtkid2002

Aerohead - If I had an all custom body that had a Cd of .18, using the stock VW engine, what do you think the mileage would be?

Also, I noticed on Aerocivic that the rear underside of the boat tail slanted upwards. Is something like that ideal or should I just stick as closely to the template as possible.

Right now I've got the top-looking-down view mostly sketched out, overlaid on the chassis. I can't use photoshop for crap so I'm doing it by hand. Right now I'm trying to follow the template for the most part, but I don't really like the idea of having it inflated a complete foot over where the chassis is, so it goes down in steps. Here's a picture of what I mean.



(Yes, I know not all the lines match up, but the jist of it is all I need right now)

Should I try and follow the lines I drew up, or just inflate the sides so it very strictly follows the template?

gtkid,if you maintained the frontal area and dropped the Cd to 0.18 that would be a 63.6% drag reduction.
At 5% better mpg per 10% drag reduction @ 55 mph,you're looking at a 31.8% improvement.If you started at 28 mpg,you might expect 36.9 mpg.
If you cut the roofline down a bit like the Ghia,40 mpg would be easy.
I'm going to have to look at your image.Sorry! missed that.
The bug has beautiful body side camber when viewed from above.If you line up the Template at the 'high point' for the sides you can use the Template to do the sides.
I would not widen the front as that would aggravate the frontal area.
If I'd kept a 1974 issue of Hot VW Magazine I could have shown you a concept for a very properly modified Bug and Ghia VW enthusiasts proposed before VW AG killed those cars.
I'll look at your drawing.