Cars ride on guide wire from start of track to end of track
Co2 cartridge is punctured –propelling car forward
Two cars race
Cars go through end gate
light goes for fastest car
Race time is recorded for each car
What do you use for the track?
Many times when people are new to CO2 racing, they hear about cars running on a "track" and think that a track specially made for CO2 cars is needed to race them.
We will race our cars on the floor. You can easily build a simple and inexpensive race track. Not as good, but a lot cheaper
CO2 Racetrack
The only track required is 50# test fishing line.
Fishing line is used as a guide line that the eye-hooks on the bottom of the cars attach to.
The fishing line runs between the start gate and the finish gate
We will likely run our races using only fishing line along the concrete floor of my lab. The smoother the surface, the faster the times will be.
length of the track
The length of the track is also important. You need to have at least 60 feet without any obstructions. Any shorter distance than this, and the cars will destroy themselves upon finishing a race.
The optimum track length is 66 feet (20 Meters), which is in scale with real dragstrip lengths of a quarter mile.
How fast are these things?
Up to 60 mph (100 kmh)
Engineering Principles
The following Engineering Principles
Relate to how and why a CO2 car works
Newton’s Laws of Motion
Mass
Drag
Friction
Newton’s 2nd Law of Motion
greater force = greater action.
Acceleration is dependent upon the mass and force of the car.
Scientifically this is called drag: the resistance of wind moving over an object.
Minimizing DRAG
The Balancing Act:
– Advantages:
Aerodynamically shaped cars have less
drag so they go faster.
– Disadvantages:
Aerodynamically "clean" cars are more
difficult to build, but worth the effort
Friction
Friction is a product of gravity
• On a CO2 car, Friction occurs primarily in three places:
Between the wheels & the ground.
Between the axles & the car body.
Between the eye-hook & the fishing line.
Minimizing Friction
Make sure the axle & tires freely rotate.
Make sure the wheels are not rubbing on the car body.
Be sure to install your eye-hooks properly. Poorly aligned eye-hooks are often the cause of a slow car.
What's the best design for a CO2 car?
Your Car must meet the size and dimensional requirements of TSA.
The best design is the one that wins. There is no "one design" that is best.
Generally, the two best indicators of a good car are clean aerodynamics and high craftsmanship. Often, really good designs that are built poorly will loose to so-so designs built well.
