B

B-post

Post extending from the roofline to the base of window behind the driver’s head.

Ball joint

A ball inside a socket that can turn and pivot in any direction. Used to allow suspension to travel while the driver steers the car.

Banking

Measured in degrees, it is the maximum angle of the track, from horizontal, in a turn or on the straightaways.

Bear grease

Slang term used to describe any patching material used to fill cracks and holes or smooth bumps on a track’s surface. Can also be used as a sealer on the track.

Bell housing

A cover, shaped like a bell, that surrounds the flywheel and clutch that connects the engine to the transmission.

Bias-ply

Layers of fabric within a tire that are woven in angles. Also used as a term to describe tires made in this manner.

Binders

Slang term for a race car’s brakes.

Bite

(1) “Round of bite” describes the turning or adjusting of a car’s jacking screws found at each wheel. “Weight jacking” distributes the car’s weight at each wheel.

(2) Adhesion of a tire to the track surface.

Bleeder valve

A valve in the wheel used to reduce air pressure in tires.

Blend line

Line painted on the track near the apron and extending from the pit road exit into the first turn. When leaving the pits, a driver must stay below it to safely “blend” back into traffic.

Blister

An overheating of the tread compound resulting in bubbles on the tire surface.

Blown motor

Major engine failure, for instance, when a connecting rod goes through the engine block. Usually produces significant smoke and steam.

Bodywork

The fabricated sheet metal that encloses the chassis.

Bore

Pistons travel up and down within each cylinder, or bore, in the engine block.

Brake caliper

The part of the braking system that, when applied by the driver, clamps the brake disk/rotor to slow or stop the car.

C

Cam shaft

A rotating shaft within the engine that opens and closes the intake and exhaust valves in the engine.

Camber

The amount a tire is tilted in or out from vertical. Described in degrees, either positive or negative.

Carburetor

A device connected directly to the gas pedal and mounted on top of the intake manifold that controls the air-fuel mixture going to the engine.

Chassis

The steel structure or frame of the car.

Chute

A racetrack straightaway.

Compound

A formula or “recipe” of rubber composing a particular tire. Different tracks require different tire compounds. “Left-side” tires are considerably softer than “right-side” tires, and it’s against the rules to run left sides on the right. There are four basic components: rubber polymers, carbon blacks, oils and curatives.

D

Deck Lid

The trunk lid of a race car.

Dirty air

Aerodynamic term for the turbulent air currents caused by fast-moving cars that can cause a particular car to lose control.

Donuts

Slang term for black, circular, dent-line marks on the side panels of stock cars, usually caused after rubbing against other cars at high speed.

Down force

A combination of aerodynamic and centrifugal forces. The more down force, the more grip a car has. But more down force also means more drag, which can rob a race car of speed.

Draft

Slang term for the aerodynamic effect that allows two or more cars traveling nose-to-tail to run faster than a single car. When one car follows another closely, the one in front cuts through the air, providing a cleaner path of air that is less resistance for the car in back.

Drafting

The practice of two or more cars, while racing, to run nose-to-tail, almost touching. The lead car, by displacing the air in front of it, creates a vacuum between its rear end and the nose of the following car, actually pulling the second car along with it.

Drag

The resistance a car experiences when passing through air at high speeds. A resisting force exerted on a car parallel to its airstream and opposite in direction to its motion.

Drive shaft

 A steel tube that connects the transmission of a race car to the rear end housing.

Dyno

Shortened term for “dynamometer”, a machine used to measure an engine’s horsepower.

E

Engine block

An iron casting from the manufacturer that envelops the crank shaft, connecting rods and pistons.

Equalized

When the inner liner of a tire loses air pressure and that pressure becomes the same as that within the outer tire, creating a vibration. The inner shield should have a higher PSI than the outer tire.

Esses

Slang term used for a series of acute left- and right-hand turns on a road course, one turn immediately following another.

F

Fabricator

A person who specializes in creating the sheet metal body of a stock car. Most teams employ two or more.

Factory

A term designating the domestic  “Big Three” auto manufacturers: General Motors (GM), Ford and Daimler Chrysler. The “factory days” refer to the periods in the 1950s and ’60s when the manufacturers actively and openly provided sponsorship money and technical support to some race teams.

Fan

An electrically or mechanically driven device that is used to pull air through the radiator or oil cooler. Heat is transferred from the hot oil or water in the radiator to the moving air.

Firewall

A solid metal plate that separates the engine compartment from the driver’s compartment of the race car.

Flat-out

Slang term for racing a car as fast as possible under the given weather and track conditions.

Flywheel

A heavy metal rotating wheel that is part of the race car’s clutch system, used to keep elements such as the crank shaft turning steadily.

Four-barrel

A type of carburetor.

Frame

The metal “skeleton” or structure of a race car on which the suspension parts and roll cage are mounted. Also referred to as a “chassis.”

Front clip

Beginning at the firewall, the frontmost section of a race car. Holds the engine and its associated electrical, lubricating, and cooling apparatus; and the braking, steering, and suspension mechanisms.

Front steer

A race car in which the steering components are located ahead of the front axle.

Fuel

Also known as “gasoline”.

Fuel cell

A holding tank for a race car’s supply of gasoline. Consists of a metal box that contains a flexible, tear-resistant bladder and foam baffling. A product of aerospace technology, it’s designed to eliminate or minimize fuel spillage.

Fuel pump

A device that pumps fuel from the fuel cell through the fuel line into the carburetor.

G

Gasket

A thin material, made of paper, metal, silicone or other synthetic materials, used as a seal between two similar machined metal surfaces such as cylinder heads and the engine block.

Gauge

An instrument, usually mounted on the dashboard, used to monitor engine conditions such as fuel pressure, oil pressure and temperature, water pressure and temperature and RPM (revolutions per minute).

Gears

Circular, wheel-shaped parts with teeth along the edges. The interlocking of these two mechanisms enables one to turn the other.

Greenhouse

The upper area of the race car that extends from the base of the windshield in the front, the tops of the doors on the sides and the base of the rear window in the back. Includes the A, B and C pillars, the entire glass area and the car’s roof.

Groove

Slang term for the best route around the racetrack; the most efficient or quickest way around the track for a particular driver. The “high groove” takes a car closer to the outside wall for most of a lap, while the “low groove” takes a car closer to the apron than the outside wall. Road racers use the term “line”. Drivers search for a fast groove and that has been known to change depending on track and weather conditions.

H

Handling

Generally, a race car’s performance while racing, qualifying, practicing. How a car “handles” is determined by its tires, suspension geometry, aerodynamics, and other factors.

Harmonic balancer

An element used to reduce vibrations in the crank shaft, located on front of engine.

Hauler

The 18-wheel tractor-trailer rig that teams use to transport two race cars, engines, tools, and support equipment to the racetracks. Cars are stowed in the top section, while the bottom floor is used for work space.

Heat cycle

Each time a tire is raised to operating temperature is a heat cycle.

High heat

Above normal (260 degrees Fahrenheit) tire temperature.

Horsepower

A measurement of mechanical or engine power. Measured in the amount of power it takes to move 33,000 pounds one foot in a minute.

I

Ignition

An electrical system used to ignite the air-fuel mixture in an internal combustion engine.

Intake manifold

A housing that directs the air-fuel mixture through the port openings in the cylinder heads.

Intermediate track

Term describing a racetrack one mile or more, but less than two miles, in length.

Interval

The time-distance between two cars. Referred to roughly in car-lengths, or precisely in seconds.

J

Jet

When air is sent at a high velocity through the carburetor, jets direct the fuel into the airstream. Jets are made slightly larger to make a richer mixture or slightly smaller to make a more lean mixture, depending on track and weather conditions.

K

L

Lapped traffic

Cars that have completed at least one full lap less than the race leader.

Lead lap

The lap that the race leader is currently on.

Line

Slang term for the best route around the racetrack; the most efficient or quickest way around the track for a particular driver. The “high line” takes a car closer to the outside wall for most of a lap, while the “low line” takes a car closer to the apron than the outside wall. Drivers search for a fast line and that has been known to change depending on track and weather conditions. Also called a groove.

Loading

Weight at a given tire position on a car due to aerodynamics, vehicle weight and lateral G-forces in a turn.

Loose

Also known as “oversteer”. When the rear tires of the car have trouble sticking in the corners. This causes the car to “fishtail” as the rear end swings outward during turns. A minor amount of this effect can be desirable on certain tracks.

Loose stuff

Debris such as sand, pebbles, or small pieces of rubber that tend to collect on a track’s apron or near the outside wall during a race.

Lug nuts

Large nuts applied with a high-pressure air wrench to wheel during a pit stop to secure the tires in place. All NASCAR cars use five lug nuts on each wheel, and penalties are assessed if a team fails to put all five on during a pit stop.

M

Magnaflux

Short for “magnetic particle inspection”. A procedure for checking all ferrous (steel) parts (suspension pieces, connecting rods, cylinder heads etc.) for cracks and other defects, utilizing a solution of metal particles and fluorescent dye and a black light. Surface cracks will appear as red lines. Marbles: Excess rubber build-up above the upper groove on the racetrack. Also known as loose stuff.

N

Neutral

A term drivers use when referring to how their car is handling. When a car is neither loose nor pushing (tight).

O

Oil pump

This device pumps oil to lubricate all moving engine parts.

P

Piston

A circular element that moves up and down in the cylinder, compressing the air-fuel mixture in the top of the chamber, helping to produce horsepower.

Pit road

The area where pit crews service the cars. Generally located along the front straightaway, but because of space limitations, some racetracks sport pit roads on both the front and back straightaways.

Pit stall

The area along pit road that is designated for a particular team’s use during pit stops. Each car stops in the team’s stall before being serviced.

Pole position

Slang term for the foremost position on the starting grid, awarded to the fastest qualifier.

Post-entry (PE)

A team or driver who submits an entry blank for a race after the deadline for submission has passed. A post-entry receives no driver or owner points.

Push

Also known as “understeer”. A car is said to be pushing if the front wheels lose traction before the rear wheels do. When a race car is pushing, it doesn’t seem able to steer sharply enough through the turns. Instead, the front end continues toward the wall.

Q

Quarter-panel

The sheet metal on both sides of the car from the C-post to the rear bumper below the deck lid and above the wheel well.

R

Rear clip

The section of a race car that begins at the base of the rear windshield and extends to the rear bumper. Contains the car’s fuel cell and rear suspension components.

Restart

The waving of the green flag following a caution period.

Restrictor plate

A thin metal plate with four holes that restrict airflow from the carburetor into the engine. Used to reduce horsepower and keep speeds down. The restrictor plates are currently used at Daytona International Speedway and Talladega Superspeedway, the two biggest and fastest tracks in NASCAR.

Ride height

The distance between the car’s frame rails and the ground.

Roll cage

The steel tubing inside the race car’s interior. Designed to protect the driver from impacts or rollovers, the roll cage must meet strict NASCAR safety guidelines and is inspected regularly.

Round

Slang term for a way of making chassis adjustments utilizing the race car’s springs. A wrench is inserted in a jack bolt attached to the springs, and is used to tighten or loosen the amount of play in the spring. This in turn can loosen or tighten up the handling of a race car.

RPM

Short for revolutions per minute, a measurement of the speed of the engine’s crank shaft.

S

Scuffs

Slang term for tires that have been used at least once and saved for further racing. A lap or two is enough to “scuff” them in. Most often used in qualifying.

Setup

Slang term for the tuning and adjustments made to a race car’s suspension before and during a race.

Short track

Racetracks that are less than a mile in length.

Slick

A track condition where, for a number of reasons, it’s hard for a car’s tires to adhere to the surface or get a good “bite”. A slick racetrack is not necessarily wet or slippery because of oil, water, etc.

Slingshot

A maneuver in which a car following the leader in a draft suddenly steers around it, breaking the vacuum; this provides an extra burst of speed that allows the second car to take the lead.

Splash and Go

A quick pit stop that involves nothing more than refueling the race car with the amount of fuel necessary to finish the race.

Spoiler

A metal blade attached to the rear deck lid of the car. It helps restrict airflow over the rear of the car, providing downforce and traction.

Stagger

The difference in size between the tires on the left and right sides of a car. Because of a tire’s makeup, slight variations in circumference result. Stagger between right-side and left-side tires may range from less than a half inch to more than an inch. Stagger applies to only bias-ply tires and not radials.

Stick

Slang term used for tire traction, as in “the car’s sticking to the track”.

Stickers

Slang term for new tires. The name is derived from the manufacturer’s stickers that are affixed to each new tire’s contact surface.

Stop and Go

A penalty, usually assessed for speeding on pit road or for unsafe driving. The car must be brought onto pit road at the appropriate speed and stopped for one full second in the team’s pit stall before returning to the track.

Sway bar

Sometimes called an “anti-roll bar.” Bar used to resist or counteract the rolling force of the car body through the turns.

T

Template

A device used to check the body shape and size, to ensure compliance with the rules. The template closely resembles the shape of the factory version of the car.

Tight

Also known as “understeer”. A car is said to be tight if the front wheels lose traction before the rear wheels do. A tight race car doesn’t seem able to steer sharply enough through the turns. Instead, the front end continues toward the wall.

Toe

Looking at the car from the front, the amount the tires are turned in or out. If you imagine your feet to be the two front tires of a race car, standing with your toes together would represent toe-in. Standing with your heels together would represent toe-out.

Track bar

A lateral bar that keeps the rear tires centered within the body of the car. It connects the frame on one side and the rear axle on the other. Also called the panhard bar.

Trading paint

Slang term used to describe aggressive driving involving a lot of bumping and rubbing.

Trailing arm

A rear suspension piece holding the rear axle firmly fore and aft yet allowing it to travel up and down.

Tri-oval

A racetrack that has a “hump” or “fifth turn” in addition to the standard four corners. Not to be confused with a triangle-shaped speedway, which has only three distinct corners. 200 mph tape: Also known as “racer’s tape”. Duct tape so strong it will hold a banged-up race car together long enough to finish a race.

U

V

W

Wedge

Term that refers to the cross weight adjustment on a race car.

Wedge, round of

Adjusting the handling of the car by altering pressure on the rear springs.

Window net

A woven mesh that hangs across the driver’s side window, to prevent the driver’s head and limbs from being exposed during an accident.

X

Y

Z