Using Graphite makes the biggest
difference (about 44 inches).
The second most important thing is
to make sure the wheels are aligned. (About 8 inches faster on my test
Sanding and waxing the wheels made
the car about 7 inches faster.
Having the graphite "worn
in" was about 6 inches faster than a freshly graphited car.
Having an aerodynamic shape made
the car about 5 inches faster.
Having the weight towards the back
and the back wheels closer to the back was 2 to 4 inches faster than
having them in other locations.
Using the results of these tests, my
Dad helped me build two cars. We made the shape flat and pointed to be
aerodynamic. We put the weight and wheels toward the back. We sanded,
polished and waxed the wheels. We also filed the bumps off the inside of
the heads of the axle nails. When we put on the wheels, we rolled the cars
on a table to make sure they rolled straight and made adjustments as
needed. Then we put graphite on the axles and spun the wheels a lot to
work in the graphite.
New car Results:
Using all these modification, one of my
new test cars was faster than my fastest Cub Scout car. The other one was
close but only beat one out of 10 races.
My fastest car from when I was in Cub
Scouts averaged 2.845 seconds in 10 runs. The fastest time was 2.812.
My new blue test car averaged 2.825
seconds. The fastest time was 2.797 seconds. 2 inches faster than my
fastest Cub Scout car. (0.015 Seconds faster)
My new red test car averaged 2.873
seconds. The fastest time was 2.854 seconds. 5 inches slower than my
fastest Cub Scout car. (0.042 seconds slower)
The results were a little different
each time ran them and one of the cars we made using these tips was slower
than the other. But both were fast. There's always the element
of chance that could make the difference between winning and losing.
But using these tips can give you a better chance.
Next, I'd like to test the two new cars
to find out why the red one is a little slower. And I'd like to test more
tips we've found on the Internet. Then maybe I can put my results on the
Internet so other kids can make fast cars.
1st Place Butterfield Elementary Science Fair 6th Grade
1st Place SARSEF
Engineering Middle School 3-28-2002