TheSamba.com :: View topic - Which year bug has the most aerodynamic body?

Wed Aug 31, 2011 2:42 pm

I'm thinking 57 and earlier hard tops because of the smaller front window and lower sloap over it. Along with the different shape front and rear. Or maybe 73 later super beetle hard tops because the large front window is more slanted back and the sides are curved for less wind resistance along with the front end being bubble shaped. Is there any test that anyone knows of to prove any of this? Anyways your input will be appreciated.

Wed Aug 31, 2011 3:26 pm

Later supers with the curved windshields. Less of an aerodynamic smack when you don't have that big flat windshield punching a hole in the air. It's heavier though, so you're better off with a non-Super. Once you get past that aerodynamic hurdle, you may very well be better off with an earlier car. The earlier cars will be generally lighter (albeit not by much). Karmann Ghia coupes are going to be the best aerodynamic type 1-based vehicle, but then you have to overcome an extra 200 pounds of steel... I don't know the weight difference between a super and a '59, say, but I'll bet a super is about on par with a typical Ghia. Earlier will again be lighter in this case as well.

For the record, a bus has a lower drag coefficient than a beetle, it's just a lot heavier. Find a way to trim some weight (something on the order of 1,000 lbs) and you'll have a pretty interesting comparison.

Wed Aug 31, 2011 5:33 pm

Drag is a real funny thing - sometimes what seems obvious is not. The one question is what are you wanting to do? Land speed record or just a more efficient street car? I know that pretty much anything that I have seen on the subject states that lowering pretty much any car makes a substantial improvement.

Start looking here to get some ideas. http://en.wikipedia.org/wiki/Automobile_drag_coefficient#cite_note-1

Wed Aug 31, 2011 5:47 pm

Buses have a lower drag coefficient, but a lot of frontal area--next to speed, the most significant factor in aero drag. Lowering apparently reduces frontal area. I'm really intrigued with slicking-up a Beetle to see what speed can be reached with limited hp. I think reducing frontal area is the best bang/buck.

Wed Aug 31, 2011 6:42 pm

Unless you're planning on running over 80mph, aerodynamic drag is more a function of the frontal area than shape of windshield, etc. So, lowering all around would bring the most immediate results.
Sorry if this sounds like bragging but: If you look at our record-breaking 36 HP CHALLENGE 1958 VW (73.49 mph in the Stone Stock Class) - the major difference between our car and the previous record holders, was the stance. Both previous record holders had very nice stock bugs, well restored/preserved, but standing tall.
Our car was purpose-built for this event: we went with a "Cal Look" stance (lowered front and rear) while minimizing the weight (Aftermarket fenders, bumpers, running boards, no frill interior) and drag (running small tires, low viscosity lubes). It paid off.

FYI: We will be back on the salt this year! We lowered the car a bit, dyno-tuned the engine, and fixed some problems with the shifter.

Finally, we have a request into Mother Nature: if she can't help us with a tail wind, at least ease off on the headwinds!

Dan - Beavergeezers Racing Team

If you're interested in Bonneville and the 36 HP Challenge, check it out at:
http://saltflats.com/36_HP.html
http://www.burlyb.com/

Wed Aug 31, 2011 6:59 pm

The Super Beetle wins the bug contest but take a look at the pre 67 bus or Type 2. Very interesting.........................

Burly

COEFFICIENT of DRAG
For Volkswagens

U.S. Beetle…………..0.48 (0.46 per Wikpedia.org)

Super Beetle…………0.47

Ghia………………….0.40 (unconfirmed) Type 141 top speed is basically 8 miles per
higher compared to Beetle with the same motor!

Pre 67 Bus…………...0.43 (0.42 per Wikpedia.org)

Type 3……………….0.48

Type 3 w/wing………0.34

Vanagon…………….0.44

New Beetle………….0.44 (0.38 per Wikpedia.org)

Rabbit……………….0.42

Scirocco……………..0.39

Porsche 924…………0.31

Porsche 356(1951)…..0.28

ARVW………………0.15 (1980’s Diesel VW Streamliner)

Tatra…………………0.37

Wed Aug 31, 2011 7:30 pm

Not to be obvious but:
Total Aero drag is a function of coefficient of drag X total frontal area. Although the bus has a lower coefficient, the total drag is much higher because it has a much larger frontal area. (Frontal area = height at the highest point from the ground X the width at the widest point-simple as that).

Another question may arise about the underbody drag, tires, etc. But we're not talking F1 level aerodynamics here, so we can assume that height x width is plenty accurate.

Dan

Wed Aug 31, 2011 7:39 pm

dandand wrote: Not to be obvious but:
Total Aero drag is a function of coefficient of drag X total frontal area. Although the bus has a lower coefficient, the total drag is much higher because it has a much larger frontal area. (Frontal area = height at the highest point from the ground X the width at the widest point-simple as that).

Another question may arise about the underbody drag, tires, etc. But we're not talking F1 level aerodynamics here, so we can assume that height x width is plenty accurate.

Dan

Thanx for the clarification Mr D.

Burly

Thu Sep 01, 2011 12:08 pm

:wink: "Aerodynamics are for people who can't build engines" Enzo Ferrari

brad

Fri Sep 02, 2011 11:04 am

This is why I choose the Ghia for the long term project. I figured it would be easier to get into the 1 club with it.

Fri Sep 02, 2011 2:44 pm

some body once said about the F4 Phantom
"With a big enough motor, Even a brick will fly"

sticker on the back window of my Scion XB

guess I should have cleaned the glass first

Casey

Fri Sep 02, 2011 6:20 pm

Facetious is funny, but the wise should learn from people like Costella.

http://www.sonicwind.com/costella.html

earthquake wrote: some body once said about the F4 Phantom
"With a big enough motor, Even a brick will fly"

sticker on the back window of my Scion XB

guess I should have cleaned the glass first

Casey

Fri Sep 02, 2011 7:06 pm

Hey, my running light is aerodynamic...........

Looks better than the gaping hole that was there.

Sat Sep 03, 2011 9:09 am

Mr. Motorhead wrote: Hey, my running light is aerodynamic...........

Looks better than the gaping hole that was there.

I wouldn't change a thing on that bus!!

Sat Sep 03, 2011 12:58 pm

earthquake wrote: some body once said about the F4 Phantom
"With a big enough motor, Even a brick will fly"

sticker on the back window of my Scion XB

guess I should have cleaned the glass first

Casey had I not seen the note about cleaning the window ,I thought it was flying at night or in space,seeing stars!!! on another note baja isant worth a shit for aero.thus my baja has been retro fited with early style fenders,and if I find my round tuit it will get lowered.dang life keeps getting in the darn way of having fun.
3rd note,your sion's aero is probably better than my element's

Sat Sep 03, 2011 5:28 pm

... wonder what aero number a rolling, driving pan would see? :lol:

bryan

Sat Sep 03, 2011 11:07 pm

This photo was found on a different topic

Sat Sep 03, 2011 11:46 pm

Sounds like a slammed super would be the best bet. Anyone want to build a 36hp Hoodride Super Beetle?

Thu Sep 08, 2011 1:57 pm

1938 Berlin-Rome car

Wed Oct 19, 2011 3:02 pm

For reduced drag at lower speed, look no further than the Eco-FE nerds.

http://www.aerocivic.com/