Glossary

Often a word you hear in racing has a totally different meaning at the track than it does on the street...

A
Aerodynamics: The study of how air and motion move around, over and under a racecar to create pressure on the racecar.
Annual: An event, once held two successive years, can be described as annual.
Apex: The point at which the entrance to a corner ends and the exit begins.
Apron: The paved portion of the track that separates the racing surface from the infield.

B
Backup: Referring to a spare racecar.
Backstretch: The back portion, usually somewhat straight, of a an oval race track - between turns two and three.
Banking: The slope of a race track, measured in degrees from the apron to the outside wall.
Big Three: Refers to domestic automakers General Motors, Ford and Chrysler.
Bite: Refers to the adhesion of a tire or tires to the racing surface.
Bondo: Brand of body filler.
Brickyard: Refers to Indianapolis Motor Speedway.

C
Camber: The vertical angle of a car's wheels in relationship to the chassis and the ground.
Compound: A formula that determines different qualities and hardness of a racing tire. The softer the compound, the "stickier" they are, thus creating more grip between the tire and the track. Softer tires tend to wear faster.

D
Downforce: The aerodynamic force on a vehicle.
DNF: Did not finish.
DNQ: Did not qualify.
Drafting: The practice of two or more cars running close together to minimize their combined aerodynamic drag.
Dropped cylinder: An engine cylinder that fails to function.
Dyno: Slang for a dynamometer, a machine used to test an engine's horsepower and other performance factors.

E
Esses: A series of acute left and right hand turns on a road course.

F
Frontstretch: The front portion of a track between turns four and one, usually containing the start/finish line.

G
Groove: The preferred path on a race track; sometimes called "the line."

H
Halfway: The midway point of a race.

I
IROC: International Race of Champions.
IRL: Indy Racing League.

L
Loose: A handling condition in which the racecar's rear tires lose traction first, as opposed to tight.

M
Marbles: Small marble-sized pieces of worn tires and debris that collects at the top, or outside, of a track during the race.
MPG: Miles per gallon.
MPH: Miles per hour.

N
NASCAR: National Association for Stock Car Auto Racing.

O
Outside pole: Slang term used to describe the position to the outside of the first position at the start of a race.

P
Pole: Used to describe the first place starting position in a race.

R
Rearend: Refers to the differential in the rearend housing of a racecar.
Restrictor plate: A metal plate with four holes installed between the carburetor and intake manifold to reduce air flow and thus horsepower. Required at some tracks to reduce speed.
RPM: Revolutions per minute.
Road course: A race track with both left and right hand turns.

S
Scuff: A race tire that has been run a short distance, i.e. the manufacturer's sticker has been scuffed off.
Set up: Adjustments made by the crew to the variable components of the racecar to try to gain optimum performance. Factrs which determine set up are usually educated guesses as to variables that will influence track conditions, including the weather.
Short track: An oval race track less than one mile in length.
Speedway: An oval race track between one mile and 1.5 miles in length.
Stagger: The difference in diameter between the tires on a racecar.
Sticker tire: A race tire that is new; the manufacturer's sticker is still attached.
Superspeedway: An oval race track that is more than 1.5 miles in length.

T
Tight: A handling condition in which during cornering the car's front tires lose traction first; as opposed to loose.
Tri-oval: A race track on which either the frontstretch or backstretch is diamond-shaped; as opposed to straight.

W
Wedge: Used to describe the imbalance among the weights carried in the springs of a racecar. Shifting wedge means moving a portion of the total weight of the racecar from one corner spring to another, to affect handling. Originated from the practice of driving a wedge between the leaves of a leaf spring.