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DOOOOWNforce!
Cam - May 7th, 2004 at 04:23 PM

http://www.oursl.com/images/article/3SLR-enclosed-underbody2-t.jpg
Just wondering if anyone has considered alternate forms of downforce for their beetles?
I've been checking out alot of supercars and their flat underbodies with venturis coming out of the rear. I think this would be piss easy to do on a beetle (well the flat underbody part anyway). I'm trying to think of discreet alternatives to the quite obvious German Look products out there at the moment, which are rad and all, but not what I'm looking for with an early car.

Ironically, I think the car that best shows what I'm thinking is the Ferrari Enzo (bottom two shots). As you can see in the front shot it has an almost invisible front wing. I was thinking of having something akin to this der the front bumper with an oil cooler enclosed in it, then with the apt curves to make it actually work, then feed the very little air left to pass over/under it straight onto the flat underbody. Which would be similar to the modena pic (below)
http://ferrari.jbroadtests.com/Modena/2002/Bilder/2002%20Modena%20Underbody.jpg
Now... With many turbo dub motors I've seen the exhaust(s) exit in front of the rear wheels, with a dry sump motor there should be very little below and behind the pulley. If, again, you ran bumpers (thinking out loud now) there shouldn't be any reason why you can't run a deep venturi upto the rear bumper, with channels in it... Not quite as deep as the Enzo's rear one, but deep and long enough to give the airflow under the car heaps of speed and space to eject itself straight out. And also, the air coming over the body nowhere to go but out over the top of bumper and now in the horizontally, not vertically. Ad to this a Remelle style wind deflector above the rear window and it should help the beetles somewhat "floaty" post 60MPH attitude a fair bit.
http://www.exoticcarworld.com/images/sale/Ferrari/Enzo/BS25-10.jpg
http://www.exoticcarworld.com/images/sale/Ferrari/Enzo/BS25-5.jpg

[Edited on 7-5-2004 by Cam]


Kai.A. - May 7th, 2004 at 09:21 PM

first of all, i reckon you think too much :P

but...

i like the way your thinking here! i'm not a fan of big spoilers/wings etc. on bugs....

i only really have two thoughts on the matter (for now...):

firstly, i think it would take a hell of a lot of trial and error to get any sort of gain, the amounts of downforce required fo a bug will be cinsiderably different to those of a supercar like, say, maybe....an enzo. you'd be starting with a completely blank sheet, unless someone else has tried this before and is willing to share their data.... so i just feel it would be a rather lengthy process....

secondly, that cool air rushing real fast past the underneath of the engine would probably be great for moving the hot air away from your motor, could see some cooler running temps. possibly.

well, there's my thoughts so far...

kai


Cam - May 7th, 2004 at 11:27 PM

haha, thanks dude :P

I think the principal would be the same. Just looking at having the bug stick a hell of alot better than what it already does. The area above the gearbox acts like a big venturi already, this coupled with the air coming down over the back window creates massive lift.
I'm not trying to get perfect balance or efficency here, just aid the car in whichever way I can.

I agree with the air going past the engine bit, I'm contemplating many ways to aid the cooling and fast escape of the "used" air from the fan.


Kai.A. - May 8th, 2004 at 12:59 AM

yeh, it all sounds cool, i'm sure i'll toy with these kinda ideas when i build my circuit racer in a year or two (or three or four.....).

i just think it would be a bit too easy to end up with too much downforce, which is about as useful as a chocolate tea pot (but not nearly as tasty).

hope i'm making some sence, it's late and beers drunkened me.

kai:cool:


AdrianH - May 8th, 2004 at 05:58 AM

Its a bit of a balancing act - downforce to power. The more downforce the more power you need to move it. Theres not much point having it stuck to the road like an F1 car if you need 700 hp to move it past 120 mph.
Having a look at ways of reducing the frontal area (lessenning the wing uplift effect and drag) in conjunction with other things might be a place to start.


BiX - May 8th, 2004 at 08:29 AM

I think the aim would be to lower lift first then to start making small amunts of down force.
For a super bug

1- add a small front buffer style board, along the front of the front T member to get more air around than under the nose
2- use rubber matting or alloy to create a fully flat under neath
3- create a rear diffuser, front diffusser
4- add side skirts

but then again, you may get better results from suspension, tire and a LSD


pete wood - May 9th, 2004 at 11:40 PM

Kimm Garland at indian reckons his car is stable at 180km/h and that it really sucks down onto the road. He doesn't know why, but the car has lowered sills and the bottom 1/2 inch of the mud flaps has worn off, so it must be happening. No other explanation.:)