How to Make a Fast Wooden Race Car

Find wheels that rotate smoothly on their axles, with as little friction as possible. It is difficult to sand wheels and make them rotate more smoothly, so, spend the extra time needed to find just the right wheels. Feel the outside of the wheels; they should feel smooth, and with no burrs or rough spots. Do not buy wheels with treads.

Smooth the axles (which are nails) by sanding or filing off any burrs under the nail heads.

Weigh the finished car, and ensure that it weighs close to 5 oz. without going over that weight (which is the limit for Pinewood Derby racers). Add small weights if necessary to approach 5 oz. Gravity forces the car down the track, but a car that is too light will lose speed while traveling the flat part of the track. Add enough wood in the back of the car to hold the weights. Use a precise scale. Post office scales work well.

Roll the car along a wooden floor to see how straight it moves. Any veering to the right or left will cut down on speed. To fix this problem, the axles will need to be adjusted. Drill new holes, do not attempt to bend the axle. Be certain which axle is causing the problem and the direction in which it needs to be moved.

Smooth the body of the car down to reduce air friction. A smoother finish will produce less wind resistance, allowing the vehicle to move faster. Start by using either a file or rasp. Then switch to coarse sandpaper and finally to fine sandpaper.

Lubricate the vehicle by squeezing a small amount of graphite onto the axle as close to the wheels as possible. Then work the substance in by spinning the wheels.