Glossary

The glossary is under construction. Please check back as more entries are added. Hyperlinks indicate that more extensive information is available.

A

Aerodynamics: Aerodynamics is the science of understanding how fluids (including air and water) interact with solid objects and other fluids. The forces created by air pushing on the car can work for or against increasing speed. See also: Drag, Downforce, Side Force, and Lift

C

Center of Gravity: The Center of Gravity, often abbreviated CG, is the point on an object at which it is in perfect balance. If the object is something simple, with a uniform distribution of mass, the CG is at the geometric center of the object (e.g. the CG for a block would be at the center of the block); however, if the object is not uniform (say, a race car), the CG has to be found other ways and may not be in the exact center of the object. The CG is important because the CG is point at which we can take gravity (and sometimes other forces) to act on the object; that is, we can pretend that the object is a point with the same mass.

Center of Mass: The Center of Mass is identical to the Center of Gravity when you're working in a uniform gravitational field. Astronomers, for example, have to be concerned about the fact that the gravitational field varies depending on how close you are the object generating it and they have to account for that separately. The difference is irrelevant for racing, but probably not irrelevant to your physics teacher.

D

Downforce: When air hits the car, each air molecule exerts a force on the car's body. We call those forces by different names depending on the direction in which they push the car. Downforce is the force of air that pushes the car straight down. Downforce is important because the grip depends on how hard the tires are being pushed into the track. More downfrorce means more grip.

Drag: When air hits the car, each air molecule exerts a force on the car's body. We call those forces by different names depending on the direction in which they push the car. Drag is the force of air in the direction opposite the car's motion. Drag is caused at the nose of the car by air molecules hitting the front bumper, and at the rear of the car as air coming off the wing creates a partial vacuum that literally sucks the car backward. Unfortunately, there is no aerodynamic force that pushes the car forward -- all of that force has to come from the engine. Note that the air usually exerts a force at an angle, so that, for example, the force on the hood is made up of some drag and some downforce.

N

NACA Duct: NACA Ducts are found in the windows to bring air into the cockpit and in the front of the car to bring air toward the brakes. A NACA duct brings air into a vehicle with minimal increase in drag.

T

Tegris: Tegris is a material that has about 70% of the strength of carbon fiber, but at about 10% of the cost. Tegris is used for the splitter and in the door as a safety element. Tegris (made by Milliken and Company) originally was called MFT for Moulded Fabric Technology, but was re-branded in 2007.

Y

Yaw: Yaw is when the direction the car is moving is different than the direction the car is pointing. Yaw became a particularly big issue for NASCAR in early 2008, when teams were introducing very large amounts of yaw into the body via displacing the rear end of the car.