better backwards

[steveW]

Somebody who appears to be intelligent suggested that an early 911 would have better aerodynamics if it were to travel in reverse.

I've spent all day looking at mine and it does seem like quite a reasonable suggestion.

Any ideas?

[MotoSook]

The 911 would be more "streamlined" traveling backward, what fun woudl it be if the engine were in front and you were facing backwards

[B D]

Probably true, but aerodynamics mean little downforce is what really matters. Better downforce facing forwards I believe.

[Dantilla]

I've heard that the early 928s had a lower Cd going backwards.

I've never heard that about a 911. Maybe.....

[MichiganMat]

Think water. Ive heard that the shape of a droplet of water is the most aerodynamic of any shape on the planet.



911s, and especially 928s, are more like a water droplet when in reverse than forwards.

[Fishcop]

At the risk of being a know-it-all A droplet of water (or any other "drop" of viscous substance) will form a sphere within Earth's atmosphere. The shape above is indicative of the droplet as it leaves its source, surface tension will pull it into a round ball very rapidly.....

[Jack Olsen]

The difference between "most aerodynamic" and "best aerodynamics for driving corners fast" are two different things. You need to generate downforce to go fast around corners, and the unmodified early 911 shape is pretty terrible for that.

[trj911]

Drive it backwards? Then the motor would be in the front just like every other car! Next someone will suggest water cooling!

[Randy Webb]

No, water drops from a shape like above as they fall due to aerodynamic forces. The Cd for a water drop shape is about 0.1

A complicating effect is that water is a liquid - not rigid. There was a guy named Lange or Lang who was doing hydrodynamics on dolphins, specifically the ability of the blubber to conform to the water interface -- funded on USN contracts. He found in one publ. that this surpressed the induction of turbulence. Then, I never saw or heard from hiim again. A few years later, the super secret new USN subs began appearing with a special special coating on the hulls. Draw your own conclusions....

[raceman]

lt was common knowledge that the original VW bug had a more efficient profile in the windtunnel-backwards.That`s probably where that came from.l pride myself on my ability to drive in reverse at high speeds(plenty of practice) but l`ll suck up the .02 and get it going forward

[Wil Ferch]

It is a well documented fact that the 928 is more aero efficient if it were to run backwards....I think the basis was total drag and lift.

---Wil

[dotorg]

Originally posted by Wil Ferch
It is a well documented fact that the 928 is more aero efficient if it were to run backwards....I think the basis was total drag and lift.

---Wil

Well damn, they should drive them that way, then. At least the motor would be on the right end of the car

[Fishcop]

Interesting Randy.... The Blub-Sub

I was thinking more about shot than water I suppose. We have a an old "shot tower" where I grew up. I was fascinated with the falling lead becoming round before being packed into cartridges etc...

[Randy Webb]

I think it must be th reater denisty of Pb -- or maybe the very high surface tension of water is involved.

Do you guys still allow Pb shot over there? I know they are trying to restric it here - not to mention the suits by landowners next to shooting ranges.

[Wayne 962]

The Aztec was designed around the theoretical perfect airfoil shape with the lowest possible coefficient of drag:



I'm in this fuzzy pic somewhere... Hmm, pretty sure I'm the tall one with the jeans/jacket...

-Wayne

[Fishcop]

Is that a mullet you have Wayne?

Randy, same boat over here... still legal for the time being, but on the way out.