Speed Tips
(or a basic physics lesson)
by
Steve Lowry
Former Redwood Empire Council Pinewood Derby Chairman
1. Potential energy is your friend: Put all the weight in the rear of the car. The further up the track the weight is, the farther it falls and the more it pushes the car.
A. Move the axles (If legal in your council) to the ends of the car, but don't let the tires extend beyond the ends of the car because they will make the car more than 7" long. This help keep the weight from lifting the front end off the track. If you are stuck with the existing wheel base use the slot nearest to the end of the block as the rear of the car and put as much weight rear of the wheels as possible without making the front end to light.
B. Remove as much wood from the car as possible without making car too fragile (Remember the car takes a real beating at the finish line), so you can put more weight in the rear.
2. Friction is your enemy: The more friction between the car and the
track the slower the car will run. 
A. Remove all the rough ridges from the axles with a FINE file. Then polish the axles with increasingly fine sandpaper(200-1000 grit) , then with polishing compound and finally graphite with carpenters pencil. Do this by putting the axle in a standard drill or Dremel drill and spin them while working with the file, sandpaper and then pencil.
B. Angle the axle heads so less axle head touches the
wheel.
C. Round and smooth wheel hub where it touches the car to minimize the area that touches the car. Polish 1000 grit and graphite with carpenters pencil.
D. Use carpenters pencil to work graphite into axles and wheel hubs and use thick draftsmen lead for inside the wheels.
E. Work copious amounts of graphite into the paint while tacky (not quite dry) where the wheel hub touches the car.
F. Indent car body where wheel touches the car to minimize touch area. Do this by grinding a little above axle hole and a little below axle hole.
G. When redrilling axle holes, raise one wheel off the track. I always lift a front wheel, but lifting a rear wheel is an interesting idea.
H. Use fine graphite (and lots of it) and work it into the wheels by spinning the wheels on the axles with a drill before putting them on the car.
3. The Center Rail is Slow: The straighter the car runs, the less it hits the center rail and the faster your car will be.
A. The way you create a straight running car, first starts with a good test road.
B. A good test road is stiff a flat, smooth, surface about 8 ft. long that you can incline and level from side to side.
C. Start your test procedure by putting a dot on the edge of each axle head with a permanent marker . The dot lets you keep track of how much you have turned it. Now you can angle the wheels in and out ever so slightly by rotating the axle, one direction or the other because every axle has a slight bend to it. This process is a tedious one but it can make your car very fast, if the axles were put in straight in the first place.
D. The best way of making the above process easier is to put the axles in straight at first. Having access to a drill press and being very careful when the new holes are drilled for the axles helps a lot.
E. Don't be afraid to build another car if you can't get the car run straight. Practice makes perfect.
Important: The Pinewood Derby is YOUR SON'S project. These tips are for you to pass along to your son. The younger Cubs need more help, but the older ones, especially the Webelos, should do it themselves. If they don't have the attention span or drive to do a good job so be it. The car should only be as good the Cub is willing to put the time into it.
Remember to check with your local Pinewood Derby rules before using any of these procedures to make sure they have not been deemed illegal.