I'm building a car and racing it tomorrow

[Huskymaniac]

http://www.wink106.com/common/page.php?id=631

Myself and three other people need to build a pinewood derby car out of Legos and run it down an ice track. Any suggestions? I'm thinking we should keep the center of mass at the exact center of the car so, if it starts spinning on the ice, it won't wobble. Not sure about long and skinny versus short and wide or if a bigger wheelbase is better or worse in this case. I guess it depends on whether or not one assumes the car will lose traction and start spinning. If it spins, you don't want a large rotational inertia to rob you of energy. However, a large wheelbase might keep it from spinning. Since we won't have limited slip differentials (or will we...) I have to think it is likely we will lose traction one wheel at a time.

[wdb]

I wouldn't bank on the track not having dividers to keep the cars apart. Too long a wheelbase might jam you between the dividers. You might want to wait until you see the track to make wheelbase decisions.

I'm torn between centered weight down low and hanging as much as possible on the downhill end. Again, the track may make that call.

Aero is good too, even at this scale. Smooth lines, super low so no air can go under, heck even a rear diffuser sloped at the classic 15 degree angle!

Make sure you have low rolling resistance. Smooth what you can. And align the wheels as well as you can manage too.

And beer.

[Huskymaniac]

One problem is that we will be limited to the box of Legos they give us.

[LetItSnow]

Nose heavy deltawing? Figure, the back would probably keep things straight.

Pics or it didn't happen!

[EdWindows]

Make sure to build it with AWD so you get the best traction.