Golf Ball Textured Pinewood Derby Car

[Halo Blu]

Has anyone added a "Golf Ball" Texture to their car before?
There's a 'Myth Busters' episode that explores the question why Golf balls have divots, and the answer is- To make the ball more aerodynamic, and less resistant to air, and travel farther, faster. So, they added the texture to a midsize sedan, and through their tests, they proved a car with that kind of exterior skin was better in every aspect of the car without.
Apply the same texture to a Pinewood Derby Car, and it might have similar findings. Removed wood weight, more aerodynamic, able to travel further- faster!
Seems logical... (???)

[video]https://www.youtube.com/embed/LKxEkT2H8pI[/video]

 

[Halo Blu]

Thanks to whoever cleaned this post up, for me, the result was an 11% gain with a textured car over, one without. Not sure how this translates to Derby Cars, but I found it interesting.

 

[LightninBoy]

Thanks to whoever cleaned this post up, for me, the result was an 11% gain with a textured car over, one without. Not sure how this translates to Derby Cars, but I found it interesting.

The only place where the divots have an impact is on the edge of the shape - in other words where the shape falls away from the boundary layer of the air. A golf ball is spherical and spins, therefore there is no fixed edge and therefore the divots need to be everywhere to be effective.

In a shape like a car, where there are fixed edges, the only place the divot would have an impact is just ahead of that edge. And it doesn't need to be a divot - it can be anything that disturbs the laminar flow. In tennis balls, the fuzzy material serves the same function. Airplanes employ this same basic principle via "turbulators".

I've experimented a little with the turbulator concept. I took a thin strip of Velcro and placed it on the back edge of the car. It had no impact and even may have slowed the car by .001. However, my testing was far from exhaustive or definitive. There may be something there.

However, I'm certain putting divots all over the entire car would have no value.

 

[pony express]

A textured vinyl covering was slower than without.

 

[txchemist]

Putting many divots on a car body using a ball-pein hammer probably slowed it considerably, but I felt much better afterward!!

 

[Kinser Racing]

Putting many divots on a car body using a ball-pein hammer probably slowed it considerably, but I felt much better afterward!!

I usually just break it over my knee. It makes me feel better to know I won't have to deal with it any more.