Before reading the rest of our site, it may be necessary to familiarize yourself with some basic terms of the racing world:

Understeer: Condition in which a car's ability to turn is less than input by the driver. This occurs when the front tires have little grip, and are unable to effectively turn. This can happen under heavy acceleration.

Oversteer: Condition in which a car turns more than input by the driver. This occurs when the rear tires lose too much traction, such as when the rear tires lock under heavy braking.

Adhesive Limit: Amount of force required to cause a tire to lose grip and slide.

Coefficient of Friction (m): Value between 0 and 1 that tells how much friction exists between two surfaces. In racing the Coefficient of Friction is mostly used in reference between tires and road. A higher value of m means the tire has more grip than a tire with a lower m.

Torque: Force at a distance. The equation to find torque is Torque = Fd. Engine torque is measure in foot-pounds (ft-lb) or Newton- meters (Nm). Later in the site you will see exactly how torque affects a car.

Horsepower: Measure of power an engine is capable of. Power is equal to work over time. 1HP is equal to 550-ft-lb/s or about 745-J/s or 745-watts. An engine must use this power to overcome friction and air resistance.

Contact Patch: The small area of a tire that is in contact with the road.

G: The acceleration due to gravity. One G is equal to 32.2-ft/s² or 9.8-m/s². A car's acceleration is often measured in terms of G. This is because it is easier to measure sideways acceleration on a tire with G. As a measure of force, G is equal to the weight of the car, which will be explained later. A car that weighs 9800-N (1000-kg) accelerating at .5-G (4.9-m/s²) is applying 4900-N of force to the wheels.

Slip Angle: The angle between the direction the wheel is aimed, and the line of actual travel. At higher speeds, or low traction conditions, the slip angle increases.

    Also, in case you are unfamiliar with some basic physics equations and laws, we will give a short explanation of some:

Newton's First Law: An object at constant velocity continues at that velocity unless acted upon by a force. Everyone knows, however, that you need to apply some gas to keep the car moving at a constant speed. This is because countless outside forces are acting upon the car, including friction and air resistance.

Newton's Second Law: An applied force causes a proportional change in the object's acceleration. This is simplified in an extremely important formula: F = ma. This says that the force equals the object's mass times it's acceleration.

Newton's Third Law: Every force causes an equal force opposite in direction. When the tires apply a force to the ground, the ground pushes back with an equal force, propelling the car forward.

Kinematic Equations: The following four equations may be useful in finding some values:

    Throughout this web site, we will use a theoretical car for all the calculations. The car is roughly based on a late model Chevrolet Corvette (late 80s to early 90s model). The values are from Brian Beckman's site The Physics of Racing. The following values will be used: