How to Make a Balloon Car Go Faster

Give your balloons a good stretch before inflating them to loosen up the material.

If you want to become a balloon car racing champion, you can do it by making a few small changes to your balloon car. This project doubles as an educational science experiment and as an entertaining activity to share with your friends. Knowing what makes a balloon car go as fast as possible gives you the ability to modify your car to win every time--in which case, maybe you won't want to let your friends in on the secret.

Instructions

1. Streamline your car before attempting to alter its speed--the best balloon in the world won't help a poorly designed car. Choose a lightweight yet sturdy material such as cardboard or poster board and cut the car so it is wider in the back and thinner in the front. This provides stability while creating less resistance pushing back against the car.

2. Choose wheels made from a smooth material wide enough that the car won't wobble or fall over during use. Check that the wheels roll freely without getting stuck or scraping against the car. The smoother the surface of the wheel, the less friction between it and the ground and the faster your car will go.

3. Race the car on a smooth surface. A tabletop works best. It gives the wheels a surface to grip but doesn't cause any excess friction. If your car slides on the smooth surface, try a slightly rougher surface, like the floor, to give it just enough traction to shoot forward.

4. Attach a regular round party balloon to your car and fill it up with as much air as possible. The more air in the balloon, the faster the car will go. A balloon you've blown up several times will stretch slightly and hold a little more air than a rigid balloon fresh out of the package.

5. Fill the balloon as much as possible and hold the end tightly to prevent any air from escaping. Release the end when you're ready and watch your car zoom away.

References

• Science Squad: Balloon-Powered Car