beetle and aero

[pickstock]

theyve got lots of work

whether theyve been tunneled or anything is different

[yodogg]

I can't find the link anymore but the shells (with front and rear aeros) most certainly have been wind tunnel tested for minimized lift and optimized high speed stability (ie balanced down force at nose and tail). Of course, wind tunneled or not, it's what happens on the track that matters. Fun Cup cars have become as attractive as they are because they are able to go fast (120-130+ mph) and really handle without lifting (take a look at the undulations and elevation changes that occur along the Spa course- it routinely spits out cars that can't keep their noses down) for, in racing terms, relatively little money.

[pickstock]

ok yeah we dont have anythign like that here, if you buy the bodies i spose they have area done

i expected them all to be built in peoples back yards as most motorsport is here

[yodogg]

Hi Pickstock,
I, like you, am more interested in backyard/homemade solutions. But that doesn't mean I can't look to the Fun Cup mods for inspiration. The effect of the front spoiler should be easy enough to duplicate with 18-22 gauge sheetmetal and a big hammer. I'd look up as many pics as possible of the front end of the fun cuppers (side views and head on) and focus on trying to get the angle and dish (curve) right. You needn't be perfect for it help.

It is a bit harder to make an effective reproduction of the rear wing. However, if rather than trying to reproduce the curve of the wing, you simplified the design by using a blade of sheet metal (6"x48" or thereabouts, sheetmetal of 18g) with a straight 2" lip of 15-20 degrees (think Harrold Helper on steroids). I would just look on eBay or performance sites for a pair of adjustable brackets long enough to place your wing up around roof height. From there you will need to spend time on the road testing and and fine tuning your mods.

I think you may surprise yourself at what can be accomplished.

[FJCamper]

Rear wing?

I thought that was some kind of oversize rear window sun shade.

Makes sense now.

Next you'll be telling me you can turn these little VW's into real race cars.

FJC

[yodogg]

Hi FJC,

My goal is to become the Smokey Yunick of beetle aero!

[yodogg]

When making aero mods to the beetle body without the luxury of wind tunnels or computer modeling, beyond trial and error, you would like to look to what has been successful already or what works on similar bodied cars. The hard part with the beetle of course is that it isn't easy finding examples of either.

When it comes to similar body shapes, both the 911 and 356 have some general similarities, but the rear slope is much less severe, so placement and angle of rear mods must be reconsidered when transferring to the beetle. Another body that may have some relevance is the Audi TT, especially the first generation, while the rear drop still isn't as steep as the beetle's it is a bit steeper than the porsche's. Additionally, the TT has enjoyed some popularity in racing of it's own and therefore the mods being used there can be added to the list of potential "cheats" that can be tapped into when molding a beetle body.

When it comes to what has already been done to beetles across the world, searching through the archives of this forum and others like it, there is a treasure trove of good and sometimes great aero mods to use and perfect.

What would be nice is to try and pull them together into a single post or sticky with a series of pics of the mods, what purpose the car is being used (hot street, autox, road race, drag etc), and a drivers impression of how effective they have been.

[Wally]

Aero does have my interest a LOT too as I do some track driving like Humble as well and the car runs easily 135+ mph.
I now run a duck tail (mainly to house an intercooler), front air dam and splitter/front under tray. In this pic a temp rear 'wing' was tested at the Nurburgring:



I still think the biggest improvement that I felt was the front air dam.

[yodogg]

Hi Wally,

That is a great lookin 1303, I really like the look of the fender flairs!

The biggest improvements I noticed came with, first, lowering the ride height and then with our front spoiler.

Was there any noticeable difference in handling with the rear wing? Also, where did you get it (or is it home-made)? I have to admit that I'm a bit jealous of the "test track" you have there!

[Wally]

It was difficult to tell what and if the rear wing did as you'd have to drive on the absolute limit to find out. The Ring is a tricky track but it was hot and maybe the tires got stickier, but traction and stability did seem very good that time. So it likely did something positive and on a track at high speeds, you need all the help you can get

I have a love/hate relationship with a rear wing. Don't really like it, but it works and all the faster GT3's, GT2/GT3 RS's and what not run them, so it probably needs it even on a street car.
The wing is in the basis a aircooled.net part (RonLummus or BigWig origin?) which I made higher by adding strokes of alu and a center pod added as well for stability. Very rude, but for testing, it stayed on at least.
Took it off afterwards to improve, but haven't yet, so not much pics. Here's from the rear tho:

[yodogg]

I have a love/hate relationship with a rear wing. Don't really like it, but it works and all the faster GT3's, GT2/GT3 RS's and what not run them, so it probably needs it even on a street car.

Yes, rear wings (even ducktails, which I think look fantastic on a 911) just somehow look a bit out of place, aesthetically, on a beetle. I wonder if that contributes to why it seems so rare to see them even on road racing beetles. The more likely reason is the relative lack of aftermarket bolt-on ready options (at least in the states) available for the beatle. That, combined with the comparatively dramatic effect that lowering a bug (correctly) and reducing airflow underneath it has on stability, may make the time and hassle of building or modifying a rear wing seem unnecessary.

BTW- how much is your 1303 lowered?

[Humble]

After adding my rather large rear wing it's a wonder how I got through high speed turns without it. A large single element wing that's properly designed (or close enough) does wonders for both a porsche and a beetle. The fun cup cars, porsche cup cars and my own bug run wide wings nearly even with the roof line to get them into the air flow. It seems to make the biggest difference on the bug due to it's lift generating shape.

A good wing for the bug isn't too hard to find but they aren't cheap either. A viper gts wing, porsche cup wing or a couple from APR work great on a beetle but you'll need to fabricate your own mounting plates and stanchions.

[pickstock]

What would be nice is to try and pull them together into a single post or sticky with a series of pics of the mods, what purpose the car is being used (hot street, autox, road race, drag etc), and a drivers impression of how effective they have been.

i say go for it

this thread was made for it, but got way out of my league

[FJCamper]

Wings, air dams, spoilers, etc., all add drag, and we of little horsepower have to always keep that in mind.

Porsche's first "aero" design was the RSR, the duck tail and front air dam adding to stability without adding drag. Read that again. More stability but no added drag. It was an engineering miracle.

By the time Porsche went to the whaletail, they had the extra power to push it.

Beetle-shaped cars really benefit from a rear wing or roof spoiler that breaks the vacuum from the non-racy people's car rear end, not that it has to add downforce. They feel the stability and mistake it for downforce.

Real downforce takes a a big wing set at an attack angle relative to the level track surface to make downforce. Leaping over hill tops ("getting air") can make lift for a moment!

And drivers fall in love with downforce once they experience it. But from a championship campaign point of view, do we have the power to overcome the downforce drag?

917's did. The last series of them were aerodynamic bricks, all drag and downforce just to stay on the ground.

We modest Beetle Bug guys have to tradeoff very carefully. A Herrod's Helper is more efficient than a fancy duck tail for us.

FJC

[Wally]

.. do we have the power to overcome the downforce drag?


FJC

Dude! read my sig again. Now read that again