Pinewood Derby & Aerodynamics

[5KidsRacing]

So last night I helped my friend and his kids tune their cars. One car was a thick wedge and was generally aerodynamic, the other was made to look like a pwd track with little cars on it... That car was full block height in the back and then it curved down to maybe 1/2" in the front... It looked like a PWD track and had little cars glued to it and all.... cool car. They both had the same parts and the track car was .080 slower. Both were steady and no wiggles, but I couldn't do anything to get that pwd track car faster.

So not that I doubted you John, but this video was spot on...

[video]http://www.youtube.com/watch?v=skpQVJfTm9E&feature=youtu.be&a[/video]

 

[txchemist]

If your kid wants to add a bunch of stuff to the car, try and make every edge smooth. This data comes from the video and shows the effective drag coefficient. The sharp edges of the flap are very bad.