| [ Total Views: 1867 | Total Replies: 13 | Thread Id: 19060 ] |
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 Cam
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| posted on February 16th, 2004 at 11:03 AM |
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most aerodynamic beetle
Hi everyone...
This was covered briefly in the the slat flat topic. But I was just wondering what is the most aerodynamic model beetle?
Thanks,
Cam
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VWCOOL
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| posted on February 16th, 2004 at 01:35 PM |
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I think it's the Oval. Low screen/roofline, curvy guards... but they're all terrible, really
Pay your debts, CxxT
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Cam
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| posted on February 16th, 2004 at 01:37 PM |
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Yeah, I know. They're all pretty dodgy. I'm thinking oval with shaved rain gutters and flush fit winscreen.
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Kai.A.
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| posted on February 16th, 2004 at 02:01 PM |
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apparently the windscreen is one of the worst areas aerodynamically..... i believe it's slightly better on an '03 because it's curved,
but the front of an '03 is basically fatter so that probably cancels it out....
this car has the right idea, guide the air over the windscreen.....
kai
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70AutoStik
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| posted on February 16th, 2004 at 10:15 PM |
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Not sure on the beetle, but I do remember that the Kombi was the first passenger vehicle to be streamlined in a wind tunnel - got the Cd down to .34
if my memory serves...
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modulus
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| posted on February 16th, 2004 at 10:40 PM |
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That's my recollection as well, but I can't back it up with data at the moment.
so the most aerodynamic 'beetle' would probably be the Karmann Ghia, followed by the Bus, followed by the Beetle as the least aerodynamic
'Beetle'.
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fullnoise
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| posted on February 17th, 2004 at 01:31 PM |
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Aerodynamic Oval - I doubt it.
When I'm driving at decent speed in the rain the drops on the front windscreen don't know where to go.
You'd think they would go up the screen or perhaps to the side in straight lines but they don't. The drops tend to stall, change direction
and even go down the windscreen at high speed. Perhaps a beetle would be more aerodynamic if it was going backwards.
Mind you I've tried that at high speed at Eastern Creek in the wet. But I was too shit-scared to notice what the drops on the windscreen were
doing.
CYA, CT
esratrams
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Cam
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| posted on February 17th, 2004 at 07:42 PM |
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Going around in the wet is very scary. Makes for good footage is people are video-ing it tho 
I think deflectors on the bonnet will be the way to go. I'd just have to try to make them look like an original accesory I guess.
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1303Steve
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| posted on February 17th, 2004 at 08:18 PM |
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Hi
I cant see how a Kombi would be more aerodynamic than a bug, it has a much larger front area to start with and no slopping bonnet.
I reckon a 1303 (L bug) with early headlights would be pretty good.
I agree when I have driven Ghias at speed they seem to get along well with less throttle than a simlar powered beetle would.
1302Steve
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VWCOOL
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| posted on February 17th, 2004 at 09:29 PM |
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Aerodynamic efficiency and the car's total drag are two different things... A car can be more efficient, but have more total drag (ie require
more power to punch through the atmosphere) because of a larger total frontal surface area.
Pay your debts, CxxT
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BiX
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| posted on February 18th, 2004 at 12:58 PM |
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Doesn't Cd take into account the frontal area of a car or object?
Cd = Drag force / ((1/2) * p * A *(U^2))
Noye; drag force = total force due to both friction and form
A= representive area - eg largest x-sectional area of object. |
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HotRodMatt
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| posted on February 18th, 2004 at 01:07 PM |
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| Quote: |
I cant see how a Kombi would be more aerodynamic than a bug, it has a much larger front area to start with and no slopping bonnet.
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Much of the Beetle's drag is caused by it's backend. A sudden drop off like a kombi or off the end of a wing reduces drag considerably.
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2443TT
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| posted on February 22nd, 2004 at 02:16 PM |
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Just curions, but are we talking about aerodynamic drag or lift.
Because at a certain point (speed) the shape of the curved body with flat chassis causes the vw to actually want to fly.
From what I've read this was due to the air in front of the car passing underneith it without changing pressure, but the air going over the car
and around it creating a low pressure region above and behind the car resulting in lift.
From what I've read there is only two way to cut down on the lift effect.
They were to attach wings to the car to provide additional downforce to counderact the lift effect, which looks kind of silly,
or
to reduce the pressure under the car by using a front wing/spoiler and diverting air aroung the car, making a low pressure region under the car.
Going faster only requires more horsepower, who cares about drag.... The way I figure it is that if you are want to go fast, its more important to he
able to control the car at speed without turning into a fireball!!
Cheers,
Ian.
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modulus
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| posted on February 22nd, 2004 at 05:24 PM |
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| Quote: | Originally
posted by iswinkels
...Going faster only requires more horsepower, who cares about drag....
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Well, errr, umm, yes, for certain values of the word 'yes'. Sufficient horsepower will overcome the aerodynamic drag, but it's worth
thinking about what sort of quantities are involved.
At urban speeds, the main source of drag is frictional, and this tends to go up in part proportionately with speed and part proportionately to the
square of the speed. Roughly speaking, going from 50 kph to 100 kph, the frictional drag will increase by a factor of about 2.8 times that at 50
kph.
At speeds where aerodynamic drag counts, this part of the drag increases as a fiunction of the cube of the speed. Roughly speaking, going from 100 kph
to 200 kph, the aerodynamic drag increases by a factor of about 8 times. It's easy to see, that at land-speed-record type speeds, the major drag
component by far is aerodynamic and it increases very rapidly with each minor speed increase.
Consequently, it is easier to go a bit faster by taping over the body joins (...within the class rules..) than it is by adding a second stage
turbocharger.
That said, going really fast requires lots of horsepower as well as painstaking attention to aerodynamics.
hth
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Cam
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| posted on February 23rd, 2004 at 06:46 AM |
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I think a venturi at the rear of the car, with a spoiler at the front and just above the drop off in the roof would make a dramatic difference to
downforce. As for wind resistance.... A deflector on the bonnet, which channels the airflow around the car, shaved rain gutters and some sort of
deflector running vertically on the a pillars.
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Jenny
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| posted on March 3rd, 2004 at 07:16 AM |
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Eureka!
The most aerodynamic Beetle? That's got to be a Eureka!
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