4 barrel

A-car

A-frame

A-post

A/C

ABS

advertised duration

A measurement of lifter rise that is not taken at a consistent point. For this reason advertised duration numbers can vary greatly, and should not be used in the comparison of camshafts. Manufacturers determine the advertised duration by using the following formulas: Intake: Degrees BTDC intake valve begins to open + 180 degrees of crank rotation + degrees ABDC intake valve begins to close = advertised duration.Example: 33 degrees BTDC + 180 degrees + 67 degrees ABDC = 280 degrees.Exhaust: Degrees BBDC exhaust valve begins to open + 180 degrees of crank rotation + degrees ATDC exhaust valve begins to close = advertised duration.Example: 69 degrees BBDC + 180 degrees + 39 degrees ATDC = 288 degrees.

aerodynamics

Air Bag

(1.) A type of passive restraint with an inflatable bag in the steering wheel or in the dash ahead of the front passengers. In a front-end collision, a sensor at the front of a vehicle will immediately cause the air bag to deploy and inflate, preventing the driver and passenger from being thrown into the steering wheel, dashboard, and windshield.
(2.) An inflatable bladder used either in place of a spring or in conjunction with a spring to compensate for changes in load by increasing or decreasing air pressure.

air box

air cleaner

air dam

A fiberglass, rubber, or metal piece below the front bumper of the racecar, used to increase front downforce for added stability at high speeds.

airfoil

Sometimes called wings, these aerodynamic devices improve traction by increasing downforce on a vehicle. Though airfoils improve cornering and provide stability at higher speeds, they do increase drag.

align bore

alignment

all motor

a term to describe a vehicle with a normally aspirated engine; an engine without nitrous, a supercharger, or a turbocharger

all wheel drive

(1.) Drivetrain where every wheel is under power.
(2.) NIRA division of heads-up racing. Allows 4 cylinder engines only, and you must be an NIRA member to compete.

alternator

A belt-driven device that powers a vehicle's electrical components and recharges the battery while the engine is running.

AN

Short for Air Force/Navy or Army/Navy. This is a very high quality grade of automotive and aircraft plumbing and high pressure fittings, often used in brake and fuel lines.

An electrochemical process used to get a controlled surface oxidation on aluminum parts to protect them from corrosion. Anodized parts can be dyed in a variety of colors.

anti-sway bar

A metal bar attached across the width of a car, front or rear, designed to resist body roll during turns by transferring load or force from the inside wheel to the outside one.

antilock brakes

This is an electronically controlled braking system that prevents the wheels from locking up under hard braking, by automatically engaging and releasing the brakes.

apex

(1.) In oval track it is the point of a turn closest to the edge of the track. Race drivers typically get in close to the apex of turns, trying to straighten their line and save time. (2.) In sport compacts, apex refers to one of the three tips on the rotor in a rotary engine.

apron

A paved portion of the racetrack between the infield and the actual racing surface.

aspect ratio

The relationship of a tire's section height to section width.

aspirated

A term that describes how an engine receives air. A "normally" aspirated engine is one that is not turbo or supercharged.

autocrossing

A test of driving skills and speed through a course of pylons.

average spring rate

A ratio, expressed in pounds of tension per, that provides an estimation of how changes in spring installed height will affect seat pressure.

AWD

Abbreviation for all wheel drive. See all wheel drive.

B-post

This is the post behind the driver's head that extends from the roof line to the base of the window.

back clearance

The measurement of space between the inside diameter of the piston ring and the base of the ring groove, when the ring face is flush with the ring land of the piston.

backspacing

The distance from the mounting surface of the wheel, which contacts the hub, to the back of the rim flange.

balaclava

A ski mask style fire-resistant hood with an open face or eye cutouts, made with Nomex or Proban, worn under helmets during a race by drivers and some pit crew members (sometimes called a head sock).

ballast

Extra weight used to reach race class weight requirements. The weight can be used to improve handling in circle track applications by adjusting preload, changing travel, etc.

Banjo chassis

NASCAR chassis designed by Banjo Matthews that was widely used in the 1960s, 70s, and 80s Winston Cup racing.

banking

The sloping area of a racetrack from the apron to the outside wall, more specifically at a curve or corner.

bbl.

An abbreviation for barrel, as in 4 bbl. carburetor.

BDC

Short for bottom dead center. See bottom dead center.

bead seat

The area where a tire rests and seals on the inside of the wheel flange.

bear grease

Slang term for a patching material used on racetrack surfaces to fill cracks and holes or smooth bumps.

bearing

A device that supports, guides, and reduces the friction between fixed and moving parts, such as those designed to surround journals on a rotating shaft, holding the shaft in place. For example, main bearings hold the crankshaft.

bearing cap

The bottom or removable half of the seat where the bearing is placed.

bearing crush

The extra bearing material that extends past the housing bore when pressure is exerted on the bearing during installation.

bearing eccentricity

A gradual reduction in the wall thickness starting at the crown and ending at approximately .380 in. from the parting lines.

Beemer

Slang term referring to a BMW.

bellhousing

The metal cover that fits over the clutch and pressure plate assembly on a manual transmission, or over the torque converter on an automatic transmission. It also attaches the transmission housing to the engine block.

belly pan

An aerodynamic pan that smoothes the motion of air under the chassis.

bench racing

Jargon for discussions about racing hypothetical cars at hypothetical races.

bias ply

Term used to describe tires that are made with layers of fabric woven in angles. Also refers to the method of constructing them. (Last used in NASCAR in 1992).

big end

The larger end of a connecting rod that connects to the crankshaft or, on a drag race track, the end of the track when you achieve your highest mile per hour.

billet

A part machined from a solid piece of metal, such as aluminum, would be a billet part.

binders

Racing jargon for brakes.

biscuits

Nickname for rubber suspension or engine mount bushings.

bite

The grip or traction a tire can get on a particular surface.

bleed rate

The time it takes the hydraulic lifter to lose its pressure once it is fully pumped up solid with oil.

blend line

The track area near the apron that is divided from the racing surface by a painted line. The area extends from the pit road exit up to the first turn. It allows drivers to safely rejoin the field on the racing surface.

blower

A nickname for a supercharger or turbocharger.

blown engine

Refers to either a supercharged engine or a ruined engine.

Blue Oval

The nickname for Ford Motor Company's emblem.

blueprinting

the machining of parts to match the exact design of the manufacturer

bolt circle

The number of lug holes on the diameter of the imaginary circle that each lug hole is centered on.

bolt-ons

Parts that are designed to simply be bolted on with hand tools without any other major effort or modifications.

A cylinder's diameter. Also used to describe the process of increasing a cylinder's diameter, as in bore the cylinder.

Boss Motor

A high performance Ford 302, 351 Cleveland, or 429 V8 engine, found originally in 1969-71 Mustangs, called Boss Mustangs.

bottom dead center

The lowest point of piston travel in the cylinder bore.

Bowtie

The nickname for Chevy's emblem.

Boxer

Any engine that has its pistons moving in a horizontal or back-and-forth motion, rather than an up-and-down motion (like a boxer's fists). Porsche and Subaru currently produce Boxer engines.

bracket racing

Type of drag racing that uses dial-ins and handicapping to give a fair competitive field.

brake fade

This temporary phenomenon occurs during heavy brake application when brake fluid and/or rotors become overheated, reducing the effectiveness of brakes.

brake horsepower

The measure of usable power at the crankshaft.

break-out

Also termed as run-under. In drag racing this is when you run quicker than your dial-in time, resulting in a loss unless a double break-out occurs.

bulb

See red-lighting.

bump steer

The change in a tire's camber and toe-out caused by hitting bumps.

bumpstick

A nickname for camshaft.

burned piston

A lean condition in a cylinder causing significant heat to burn a hole through a piston.

burnout

the pre-drag race act of spinning the tires of a racecar in order to heat them up and remove debris to increase traction during the launch

bye run

In drag racing, this is when one races unopposed.

C

Celsius or Centigrade, a measure of temperature.

C-post

The post that extends from the top of the deck lid to the base of the rear window to the roof line.

c.i.d.

Cubic Inch Displacement. The volume of an engines cylinder and combustion chamber, with the piston at bottom dead center, multiplied by its number of cylinders. (bore x bore x stroke x .7854 x no. of cylinders)

cam

(1.) An eccentric (off-center) lobe or projection on a rotating shaft used to transmit a motion at a predetermined time during the rotation of the shaft.
(2.) Short for camshaft.

cam button

A device, sometimes called a thrust button, which keeps the camshaft in place.

camber

The angle of the front tires in relation to the road surface. When the tire is straight (or sits square), the camber is 0. When the top of the tire leans in, the camber is negative; when the top of the tire leans out, the camber is positive.

camshaft

A rotating shaft with a number of cams or eccentric lobes used to operate the engine valves, usually via pushrods and rocker arms.

CAP

Competition Award Points. IASCA points award in competition.

CART

Championship Auto Racing Teams, an Indy Car and Formula 1 race sanctioning body run by racing team owners

caster

The angle of the ball joints in the steering gear. If the angle is toward the front of the car, the caster is negative; if the angle is toward the back of the car, the caster is positive, which forces the tires to stay straight.

cat-back exhaust

An exhaust system that includes all the components from the catalytic converter back, including the muffler and tailpipe.

cc

Cubic Centimeter. A measure of volume. Often used to determine the size of cylinder head combustion chambers.

centerline

This usually refers to the camshaft positioning or timing in relation to the crankshaft phasing. It is expressed as the number of degrees the crankshaft must rotate after TDC until the number one intake lobe has reached its peak.

cfm

Cubic Feet per Minute. A measurement of air flow, such as through a carburetor.

chassis

The steel structure or frame of the racecar.

chopped

A slang term describing the customization of a vehicle’s roof by cutting the pillars and glass to lower the height of the roof.

Christmas Tree

An electronic Drag race starting system that consists of a series of lights used to start a drag race. Each lane has two Pre-Stage lights, two Stage lights, three yellow lights, a green light, and a red light.

chute

(1.) Starting position for a grag race; a car that is properly staged is "in the chute"
(2.) Fast, straight section of an oval track or road course.
(3.) Parachute, used to slow both drag and lake scars from high speeds. In drag racing, a chute is required on any car capable of 150 mph or more and at Bonneville, on any car faster than 175 mph.

circuit breaker

A device designed to break the electrical connection or circuit in the event of an overload. Circuit breakers may have either an automatic or manual reset.

closed exhaust

An exhaust system that has full length pipes and mufflers.

Club racing

The term used by the SCCA to refer to road racing.

clutch assembly

The combination of the clutch and pressure plate.

clutch lockup

(1.) The progression of clutch disc engagement controlled by an air timer management system
(2.) The action of a torque converter clutch in an automatic transmission reducing engine speed at cruising rpms

cog swapper

Slang term referring to a transmission.

cogs

Slang term referring to gears.

coilovers

These shock absorbers that have an integral coiled spring built around them are replacements for the spring and shock/strut in a suspension system. Their advantage is height adjustability, and more performance-oriented tuning.

coking

Oil that hardens or thickens in an engine due to excessive heat.

combat wing

Slang term for a stacked or "batman" style wing. It is a knockoff of the Skyline GTR spoilers.

combustion chamber

A recessed area in the cylinder head where the burning of air-fuel mixture takes place. Each cylinder/piston has a combustion chamber.

Comp 4

NIRA division of heads-up racing. Reserved for 4 cylinder-powered entries that are normally aspirated.

Comp 6

NIRA division of heads-up racing. Reserved for 6 cylinder-powered and rotaries that are normally aspirated.

compound

Refers to the formula or "recipe" of the rubber making up a tire. Tire compounds can range from soft to hard. In NASCAR the left side tires are of a considerably softer compound than the right side, and it is against the rules to run the left side tires on the right.

compression ratio

The ratio of the cylinder volume with the piston at bottom dead center to the cylinder volume with the piston at top dead center.

condenser

a device used to store electricity in a points-type ignition system

contact patch

The total distance from the outer edge to the inner edge of the tire's tread surface that contacts the road.

counterweights

Metal weights used to balance a crankshaft.

course rally

This type of rally involves more logic. The teams follow a route at an assigned speed while trying to figure out the course destination.

cowl

Part of a vehicle structure between the engine and passenger compartments to which the windshield and dashboard are attached.

crankcase

An oil-filled housing which encases the crankshaft, formed by bolting the oil pan to the bottom of the engine block.

crown

The top surface of a piston.

Crush Sleeve

A sleeve used to position the pinion gear in the differential case and is designed to crush when torqued to a specific pressure.

cupping

An irregular wear pattern on tires, which occurs when the tire is underinflated. Because of this, the tire's tread and part of the shoulder or side rub the ground.

custom

A vehicle modified more for appearance than performance.

cut a light

Getting a good start at the beginning of a drag race, measured against the countdown lights on the Christmas Tree.

dB

Decibels. A measurement used to express differences in power of sounds loudness in audio systems.

deck lid

Refers to the trunk lid.

deep staged

This occurs after a driver is staged and rolls a few inches farther to cause the pre-stage light to go out, but also comes closer to a foul start.

deflection

Twisting or bending of the tire/wheel assembly caused by wheel flex.

degree of banking

This refers to a track's slope height at its outside edge.

degreeing in the camshaft

Making sure the camshaft's position coincides with that of the crankshaft for synchronized rotation.

delay box

an electronic device which allows a driver to initiate a run by releasing a hand held button instead of depressing the accelerator, thereby decreasing reaction time

detonation

Irregular combustion of the air/fuel mixture when it burns too rapidly, resulting in an audible knocking or pinging.

dial-in

(1.) Used in bracket racing to give all racers a fair chance. It is the ET that you think you can repeat. Dial-ins are used in eliminations to set handicaps.
(2.) Also used to describe tuning an engine to its maximum performance.

dialing under

In handicap elimination racing where break-out is in effect, NHRA Stock and Super Stock competitors can opt to select a time faster than the national index.

diaper

A blanket that encases the oil pan to serve as a containment device in the event of an engine explosion. This blanket is often made from ballistic and absorbent material such as Kevlar.

die casting

A process that includes pouring molten metal or composites into a mold or die under pressure, producing smooth, accurate castings.

differential

Gearing device which transmits power from a driveshaft or transaxle to the driving axles, and which also allows the wheel on the outside of a turn to rotate faster than the wheel on the inside to prevent tire scrub

directional tires

Tires designed to be used in one direction of rotation, usually indicated on the tire with an arrow.

dirty air

Air turbulence caused by fast moving cars that can cause a car to lose control.

DIS

Distributorless Ignition System. An ignition system that does not use a distributor, but instead has multiple coil packs to direct the voltage.

disc brakes

A braking system using rotating metal discs (rotors) fitted against the wheels. A set of abrasive linings are mounted on a caliper fitted around the rotor. The caliper compresses the friction pads against the disc, slowing the rotation of the disc and wheel when the brake pedal is depressed.

DNF

Did Not Finish. A term for a race car driver who didn't finish a race due to a crash, engine malfunctions, etc.

DNQ

Did Not Qualify. A term for a racer who did not meet qualifying requirements to be eligible for a in a race.

DOHC

Dual or Double Overhead Cam. See dual overhead cam.

donut

Turning or spinning a car in tight circles.

doorslammer

A Drag race car with a production or stock body (original or fiberglass reproduction) and a gasoline or alcohol-fueled motor.

double break-out

This occurs in drag racing when both drivers break-out. The driver who breaks-out by less and did not red-light is the winner.

double overhead cam

See dual overhead cam.

double wishbone

A front suspension system that has both an upper and lower control arm.

downforce

The downward pressure a car receives when moving through the air. This downward pressure aids in the cars hugging or sticking to the track.

drafting

The practice of driving directly behind another race car, allowing the front car to experience most of the wind resistance, causing the rear car to use less horsepower and fuel while traveling at the same speed. The addition of the rear car also reduces the drag on the front car, and effectively "pushes" the front car along (WITHOUT physical contact). Therefore, the two cars will both go faster than just one by itself.

drag

The resistance an object or vehicle encounters as it travels against air.

drag coefficient

A measure of an object's ability to move through the air, also known as its "slipperiness." An object or vehicle with a low drag coefficient would be more slippery, or would travel more easily through air than an object with a higher drag coefficient.

drivetrain

The system that transfers engine power to the drive wheels. It includes the transmission, driveshaft, differential, U-joints, and axles.

drop forging

The process of shaping metal while it is hot and pliable.

dropped cylinder

A rich condition in a cylinder preventing the spark plugs from firing.

dropping

Slang for lowering a vehicle.

drum brakes

A brake system which includes a hollow drum containing abrasive pads (shoes) around the wheel hub. When the brake pedal is depressed, the pads expand out to apply pressure to the drum, slowing its rotation and the wheel's.

dry sump oil system

A separate tank is used for the oil reserve along with an external belt-driven oil pump. It provides increased oil control, horsepower, and accessibility.

DSM

Diamond Star Motors. A joint venture between Chrysler and Mitsubishi that produced the Eclipse, Talon, Laser, Stealth, and 3000GT.

DSP

Digital Signal Processors. Their function is to take the signal from an audio system's head unit, and using an analog-to-digital processor, place the signal in the digital domain where it can be manipulated by advanced microprocessors.

dual overhead cam

An engine with two camshafts placed in the cylinder heads, over the valves. Also referred to as double overhead cam or DOHC.

Dualie

A pickup with dual rear wheels often used for towing.

dumped

A car with a radically lowered front end.

dumping

Intentionally using your brakes so your opponent will hit the finish line first, to try and force a break-out.

duration

The amount of time the valve is kept open during its tappet lift, measured in crankshaft degrees of rotation.

duration at .050 in. cam lift/tappet lift/lifter rise

The measurement for camshaft duration that is measured at an exact point (.050 in. of lift). This is the duration measurement that should be used in the comparison of camshafts.

east-west

A slang term for a transverse or sideways engine placement in a vehicle.

eccentric

(1.) When two or more holes or round parts do not have the same central axis. For example, a camshaft with its offset lobes.
(2.) The shaft the rotor moves around in a rotary engine.

eccentric bearing

A bearing that is thickest at the crown, with the ends a few ten thousandths of an inch thinner

ECM

Engine Control Module, which is an electronic device used to monitor engine operations

econobox

A small economy car

EFI

Electronic Fuel Injection. See fuel injection.

EGR

Exhaust Gas Recirculation. A pollution control system that returns exhaust gases to the engine for reburn, reducing final emissions.

elapsed time

See ET.

electrolyte

A solution that conducts electrical current, such as the mixture of sulfuric acid and distilled water in a battery

eliminations

Tournament style competition where two cars are raced at a time, resulting in one winner and one loser. The winner progresses on to another round of racing.

emery paper

A corundum-magnesite abrasive coated paper, used for sanding

EMF

Electromotive force, or voltage

endo

To flip a vehicle end-over-end

engine bay

The area of a vehicle that contains the engine and related components.

engine dynamometer

A device that measures the output of an engine at the flywheel in brake torque, which is then converted to brake horsepower. Also known as a dyno.

esses

A series of sharp left and right turns, one immediately after another on a road course, resembling the letter "S".

ET

Elapsed time. This is the time it takes for a car to go from start to the end of the quarter mile.

ethylene glycol

A type of liquid used as antifreeze

fascia

the part of a vehicle's body that is in front of the fenders; also called the nose

fatigue

The breakdown or failure of metal or other materials under repeated or extended stress.

field

The total number of cars entered in a particular race or class during an event. For example, a race with 16 cars has a 16 car field.

fire bottle

a remote activated fire suppression device; also a slang term for a fire extinguisher

flash shield

Used to protect the driver from engine backfire, this device encompasses the air inlet of a carburetor's sides, top, and rear.

flash speed

During launch, this is the rpm the engine revs to when nearing lockup. This is achieved by making a standing start in high gear with the accelerator pedal to the max (there is no holding or braking of the drive wheels) and noting the rpm at which the vehicle begins to move.

flash stall

See flash speed.

flat-out

flush fit

A condition where the wheel’s entire mounting pad fits against the hub mounting surface with no interference or obstructions.

flywheel

A large disc, cast iron, aluminum or steel, located at the rear of the engine on the crankshaft. It keeps the crankshaft turning at a constant speed and transfers engine power to a manual transmission.

foot-pounds

four banger

Slang term for a 4 cylinder engine. See also four-popper.

four on the floor

four-cycle engine

Engine operation where an explosion occurs in each cylinder on every other revolution of the crank. The four cycles are intake, compression, power, and exhaust.

four-popper

Slang term for a 4 cylinder engine. See also four-banger.

four-stroke engine

See four-cycle engine.

front-steer

When the steering box and components are located in front of the car's front axle.

fuel cell

(1.) A lightweight container, usually plastic or stainless steel, used to replace the heavier stock gas tank in a race car.
(2.) In NASCAR it is a tank for gasoline, made of metal with a flexible tear-resistant bladder with foam and baffling designed to eliminate or reduce fuel spill.

fuel injection

An intake system in which the fuel is injected or sprayed into the engine cylinders rather than mixed with air in a carburetor, ensuring more reliable, complete fuel delivery and air mixture.

fuel slosh

Liquid fuels are violently turbulent in the fuel cell during hard acceleration, cornering, braking, and from rough terrain. This usually results in fuel moving away from proper areas such as jets or pickups in tanks/cells. Most fuel cells are foam-filled to limit this problem.

fuel wash

When an engine floods from too much fuel.

full boil

Slang term for having the engine at full throttle.

furnace brazed

A process used to reinforce where a bronze paste is applied to the surface, typically on a turbine or stator, and then heated allowing the paste to fuse to the surface.

fuse

A device designed to provide protection on a circuit at a specific amperage. When this amperage is exceeded, the device will physically break or open the circuit.

fusible link

Resembling a wire, this device is designed to perform the same task as a fuse, by breaking the circuit when a specific amperage is exceeded. Most commonly used in ignition switches and other high current circuits.

G-force; G’s

The gravitational pull on a body (yours and your vehicle) that is felt when a change in direction is made, such as during hard cornering. The greater the gravitational pull, the greater the number.

gasket

A thin membrane used to seal the union of two machined parts. Generally made of a pliable material such as cork, rubber, copper, or a composite.

Gasoline Alley

Indianapolis Motor Speedway's garage area.

Gear Drive

A type of system with two or more gears, such as a system designed to transmit the rotary motion from the crankshaft to the camshaft.

gelcoat

A smooth, hard coating on fiberglass vehicle body components that provides a paintable surface.

Gilmer belt

a cogged drive belt used with a matching pulley to prevent slippage

glow plug

In a diesel engine, an electrical plug which pre-heats the combustion chamber to aid in cold weather starting

GPH

Gallons Per Hour

grease

A semi-solid petroleum product used as a lubricant

grease fitting

A fitting located on vehicle parts, particularly steering and suspension components, through which grease can be applied for lubrication. Also called a zerk fitting.

greenhouse

The upper part of a car to include the A, B, and C pillars, the entire glass area, and the car's roof.

groove

Refers to the fastest route around a track.

gross horsepower

An engine's output without accessories, exhaust system, or pollution control devices.

ground

Any metal part of a vehicle’s structure that is directly or indirectly attached to the negative side of the battery; used to conduct current from a load back to the battery

gusset

Triangular piece of metal used to add extra strength in corners, such as on a roll cage

H-car

Slang term referring to any Honda model.

hairpin

A 180 degree turn on a race course that reverses the driver's direction.

handicap

In bracket racing eliminations the time difference between two cars dial-ins are used to give the slower car a calculated head start. This calculated head start is programmed into the Christmas Tree to give the slower competitior the green light first. (Example: In time trials you run the following ETs: 13.05, 13.01, 13.07. In eliminations you decide to dial-in at 13.00, while your competitor dials in at 11.00, you will receive a 2.00 second head start.)

handling

Term referring to a cars steering agility.

harmonic balancer

A cast iron or steel disc which attaches to the front of the crankshaft and acts to counter crankshaft twist and dampen engine vibration. Also known as a harmonic damper.

header

An exhaust system piece composed of several thin-walled steel tubes which connect to the exhaust ports in the cylinder heads. Each tube feeds into a common collector tube, which transmits exhaust gases to the rest of the exhaust system.

heads-up racing

A competitive drag race with no dial-ins. Both competitors leave the line at the same time, and the one crossing the finish line first is the winner.

heat range

A measure of the spark plugs ability to dissipate heat.

heat-treated

A process in which a metal is heated to a critical temperature where its crystalline structure changes, and then quenched or cooled. This process adds strength.

HEI

High Energy Ignition. A GM ignition system which has the coil and spark control module integral with the distributor.

Hemi

An engine with cylinder heads that feature hemispherical combustion chambers that allow more air-fuel mixture in, forcing the mixture to swirl for better burning. This results in increased power.

hi-po

Slang for high performance.

high groove

When a car is closest to the outside wall for a majority of the lap.

holeshot

To beat a drag racing opponent away from the starting line by having a quicker R/T or reaction time without red-lighting.

homologation

(1.) A stock-style racing vehicle that is required by a race sanctioning body to have a production-model available for public sale.
(2.) A category of IMSA racing for non-turbocharged sports cars.

hone

A tool used in the process of honing. The two most common types of a hone are:
(1.) A three-legged hone where each leg holds a fine textured grinding stone.
(2.) A ball type hone where multiple abrasive ball stones are placed in a random pattern and suspended by a tiny flexible plastic rod.

honing

The process of enlarging or finishing the inner surface of a hole, such as cylinders or valve guides, through the use of a hone.

hop up

To modify a car or engine for better performance.

horsepower

A measurement of an engine's power output or the amount of work it does; one horsepower is the amount of power it takes to move 33,000 ft.-lbs. in one minute.

hot tank

A heated chemical tank that often uses methylene chloride to clean parts prior to machining.

huffer

A nickname for a supercharger.

I-head

Another name for an overhead valve engine (OHV).

International Auto Sound Challenge Association. A coalition of the top manufacturers in mobile electronics equipment, that provide a forum for autosound competition.

IdBL

IASCA dB(decibels) League. A division of IASCA that holds autosound competitions that classifies cars by the number and size of woofers in a system.

IDRA

International Drag Racing Association. An import drag race sanctioning body.

IDRC

Import Drag Racing Circuit. One of the largest import drag race sanctioning bodies, founded in 1997, and based out of Irvine, California.

IFS

Independent Front Suspension.

ignition interval

The interval between power strokes in a four-cycle engine.

IHRA

International Hot Rod Association, a Drag racing sanctioning organization with divisions including Top Fuel, Alcohol Funny Car, Top Fuel Harley, Pro Stock, and Pro Modified.

impeller

A rotor that transmits motion usually through the movement of fluid under pressure.

IMSA

International Motorsports Association. This is a roadracing organization.

index

Elapsed time assigned by a race sanctioning body to allow different classes to race together with a fair handicapped starting system.

inline

Internal combustion engines where the cylinders are arranged vertically and in a row, generally 4 or 6 cylinder arrangements.

Input Shaft

A shaft used in a vehicle’s transmission that receives power from the engine and delivers it to the transmission gears.

installed height

It is the dimension measured from the bottom of the retainer to the surface where the spring rests on the head when the valve is in the closed position.

intercooler

On a supercharged or turbocharged engine, a radiator type heat exchanger between the blower or pump and the engine which cools the air entering the engine that has been heated due to compression. It can be liquid or air cooled, and the object is to increase the density of air entering the combustion chamber to create more power.

IROC

International Race of Champions, an annual competition for champion road racing and stock car drivers who compete in identical cars.

IRS

Independent Rear Suspension.

IT

Improved Touring. This is the most popular entry-level production-based category of SCCA Touring. It is made up of 4 and 6 cylinder and rotary-powered automobiles with limited modifications usually centered on suspension improvements. Most vehicles are at least five model years old, but no older than 1968. Comprised of four classes (ITS, ITA, ITB, ITC), they compete only at a regional level.

ITA

Improved Touring-A. SCCA Touring class.

ITB

Improved Touring-B. SCCA Touring class.

ITC

Improved Touring-C. SCCA Touring class.

ITS

Improved Touring-S. SCCA Touring class.

jack

A device to lift one corner or end of a vehicle off the ground.

jack stands

Portable stands that are adjustable in height and placed under the axle or frame of a vehicle so someone can work safely underneath with adequate clearance.

jam nut

A thin nut tightened against a standard width nut to lock it into place and keep it from moving.b

JDM

Japanese Domestic Market.

jet car

A drag racecar that is powered by a turbine engine, usually a jet engine from a military aircraft.

jig

jimmy

(1.) Old hot rodders slang for GMC.
(2.) Also used as a designation for a specific model of a GMC SUV.

journal

The areas of a rotating part, such as a crankshaft, that are supported by bearing inserts which support and position the part.

juice; on the juice

A slang term for nitrous oxide; a vehicle or racer using nitrous.

jump start

To start a vehicle with a discharged battery by using a booster cable connected to a good battery.

jumper cables

A pair of cables used to connect a discharged battery to a charged battery. Used for jump-starting.

kilowatts

The metric equivalent of horsepower. 0.746 kw = 1 HP.

knurled

A series of small grooves or ridges on a tool or other object to aid in gripping.

lateral run-out

The side to side motion (wobble) of a wheel as it rotates.

launch

The start of a Drag race, or the way a car starts a race (takes off).

LCD

Liquid Crystal Display. Used in digital device displays (i.e. gauges, computers, etc.)

lean

Air/fuel mixture with a higher than normal proportion of air.

lean mixture

A normal air-fuel mixture for a stock application would be 14.7 parts air to 1 part fuel (14.7:1). A lean mixture would be a higher amount of air, say 15:1.

LED

Light Emitting Diode. A light shedding diode that is used for signal indicator and display purposes.

Lexan

A durable thermal-resistant plastic material developed by GE used in place of glass. Lexan is lighter than glass and shatterproof.

lifter

Small cylinders, either solid or filled with oil, that sit on the faces of the camshaft lobes. As the cam rotates, the lifters move up and down, which, in turn, moves the pushrods and rocker arms to open and close intake and exhaust valves.

limited slip differential

Mechanically limited axle shafts and drive wheels that prevent wheel spin on slippery surfaces by transferring torque to the wheel with the best traction.

line lock

A solenoid that holds or locks the front brakes so the rear tires can spin during the burnout.

little end

The smaller end of a connecting rod where the piston pin is routed through.

load rating

The maximum weight the wheel is designed to carry.

lobe

This is the egg-shaped portion of the camshaft that activates an intake or exhaust valve lifter.

lobe separation

This is the physical spacing between the intake and exhaust lobe that is measured in degrees of the camshaft. This physical spacing can not be changed unless there is a regrind of the lobes.

locker

Another name for a locking rear-end.

locking rear-end

A differential that acts as a locked rear-end in straightaways, but allows turns to be made by applying power to one wheel while the other rotates freely. This rear-end usually has a positive action, ratchet-type differential. See also locker.

lockup

The point when the torque converter has almost no slippage due to the transmission input shaft speed and engine speed nearing each other. Standard torque converter efficiency is about 94 percent, while lockup converters have 100 percent efficiency.

lockup converter

When a certain engine rpm is reached this torque converter uses an engagement clutch to lock the position and prevent any slippage. This 100 percent efficiency will improve fuel economy.

loose

In the corners this is when the rear tires have trouble sticking.

loose stuff

Term referring to debris that collects on a track, such as sand, pebbles, or small pieces of rubber.

low groove

When a car is closer to the apron than the outside wall, such as in the turns.

lowered

A slang term describing the customization of a vehicle’s suspension in order to decrease the ride height.

Lowrider

A vehicle that has been massively lowered with suspension modifications and smaller wheels. The most common feature is a hydraulic jacking system that not only allows the suspension system to be raised and lowered rapidly, but from front-to-rear and side-to-side also.

MacPherson Strut

A type of front suspension that saves space by mounting the coil spring directly above the shock absorber. The unit is attached to the vehicle at the top by the coil spring and at the bottom by a lower A-arm.

magnaflux

An inspection process for metal parts that uses magnetic powder, an electromagnet, and ultraviolet light to detect small cracks.

make

The name of an auto manufacturer. For example, Ford, Chevy.

mandrel-bent

A method of bending tubing that maintains the same inside diameter throughout the bend. This means there will be no crimping or crushing of the tube at the bend. Mandrel-bent tubing is used most often for exhaust systems. The main benefit for using this type of tubing will be no disruptions to slow the flow of exhaust gases, which is particularly important at higher rpms.

marbles

Term referring to excess rubber buildup near the outside wall area of the track.

Mazda Speed

Mazda high performance division.

methanol

Technically pure methyl alcohol produced synthetically for drag racing

misfire

Lack of an explosion occuring in one or more cylinders while the engine is running.

model

The name of an auto maker's product line, for example, Ford Ranger, Chevy Blazer.

Mopar

Nickname for a Chrysler/Dodge/Plymouth car or part, believed to be short for Motor Parts.

Mountain Motor

The nickname given to the IHRA Pro Stock class to emphasize the engine size difference from the NHRA Pro Stock class. The NHRA cars may run up to 500 c.i.d. while the IHRA cars may run up to 815 c.i.d. This term can refer to just the engine or the entire car class.

mounting pad

The smooth surface area on the back of the wheel center that contacts the brake drum or rotor.

muffler

A canister shaped device in a vehicle exhaust system used to absorb noise.

Mugen

Honda factory high performance division.

NASCAR

National Association for Stock Car Auto Racing. The sanctioning organization for Winston Cup, Busch Grand National, and Craftsman Truck Circle Track racing.

negative camber

An inward tilt at the top of the wheels on a vehicle, measured in degrees.

negative offset

When the mounting surface of the wheel is inboard of the wheel centerline.

neutral

Term referring to when a car is neither loose nor pushing.

NHRA

National Hot Rod Association. A Drag race sanctioning organizations with divisions including Top Fuel, Funny Car, Pro Stock, Pro Stock Truck, and Pro Stock Bike, among others.

NIRA

National Import Racing Association. A nationally based drag racing association.

Nissan Motorsports International. High performance division of Nissan.

nitromethane

An extremely high octane racing fuel used in Top Fuel Dragsters and Funny Cars.

Nitrous Oxide

A nitrogen-based gas which is mixed with gasoline or other fuel, then injected or sprayed into the combustion chamber. Nitrous adds extra oxygen and cools the air-fuel mixture, allowing a denser charge and hotter burning, which results in more power. Usually used in short, high rpm spurts for instant acceleration.

Nomex

A flame resistant material used in racing suits and protective undergarments.

NPT

National Pipe Thread. A standard designation for a type of threaded fitting. It allows for compatibility between different manufacturers.

NSRA

National Street Rod Association. An organization devoted to Street Rodding.

offset

The positive or negative distance from the wheel centerline to the mounting surface of the wheel.

OHC

Overhead Cam. An engine design where the camshaft is placed in the cylinder head(s) and over the valves.

OHV

Overhead Valve. An engine design that has the camshaft below the valvetrain.

oil pressure

The pressure that oil exerts on an engine and its surrounding components, typically expressed in psi or Bars.

oildown

The act of spilling or leaking petroleum-based fluids (generally oil) on a racetrack, usually the result of blowing a motor or transmission.

open chamber head

A cylinder head design featuring combustion chambers with little or no quench areas to increase breathing and develop higher horsepower.

ORV

Off Road Vehicle. A truck, SUV, or buggy used for recreational or competition purposes on unpaved surfaces.

out-of-round

a condition where a round object, such as a tire, cylinder, or journal, no longer has a perfect diameter, possibly caused by flat spots or part failure

oversteer

The tendency for the rear end of a car to spin out of a turn when the car is cornering.

pace lap

See parade lap.

panhard bar

A lateral bar connecting the frame to the rear axle. Its function is to keep the rear tires centered within the body of the car. Also known as a track bar.

parade lap

A warmup before a race, led by the pace car, during which drivers warm up engines and zigzag to warm up tires. Used also to set pit road speed, based on tach reading. Also known as the pace lap.

PC

Pro Comp. NIRA division of heads-up racing. Must be an NIRA member to compete in this class.

PE

Post-entry. See post-entry.

Pentastar

The nickname for Chrysler's emblem, and a nickname for its products.

PFW

Pro Front Wheel Drive. NIRA division of heads-up racing. Must be an NIRA member to compete in this class.

pilot chute

a small, spring loaded chute that pulls the main braking chute from its pack

PIRA

Pacific Import Racing Association. A West Coast based drag race sanctioning body.

piston

A cylinder that fits into the engine block cylinder bores and the combustion chamber in the cylinder heads. It is connected to the crankshaft by a metal rod. Its up-and-down motion, facilitated by the turning crank, allows the air-fuel mixture to expand and compress as it is ignited.

piston ring

Rings designed to fit into the grooves on pistons, providing a seal that creates compression and prevents oil from contaminating the air-fuel mixture.

Pitman Arm

A lever that connects the steering gear to the centerlink.

porting

The process of enlarging or contouring ports or chambers in a cylinder head.

posi

See limited slip differential.

posi-traction

See limited slip differential.

positive offset

When the mounting surface of the wheel is outboard of the wheel centerline.

post-entry

When a team or driver submits the entry blank after the deadline. This type of entry receives no NASCAR Winston Cup points.

pound-feet

See foot-pounds.

POW 4

Power 4. NIRA division of heads-up racing. Reserved for 4 cylinder-powered entries that have power adders (2 max).

POW 6

Power 6. NIRA division of heads-up racing. Reserved for rotary or 6 cylinder with power adders.

pre-staged

When the vehicle is about seven inches behind the starting line and the yellow pre-stage light at the top of the Christmas tree is lit.

preignition

A combustion of the air/fuel mixture that occurs before the spark plug has fired, resulting in an audible knocking or pinging.

PRO

Pro Import. NIRA division of heads-up racing. Must be a NIRA member to compete in the class.

Pro Street

A vehicle with the look of a Pro Stock Drag car, but is street legal.

Proban

A cotton-based flame resistant material used in racing suits and protective undergarments.

push

See tight.

pushrod

Hollow steel rods in the valvetrain that transfer lifter motion to the rocker arms.

Quadra-Trac

A full time, four wheel drive system offered by Jeep on its full size vehicles which incorporates an inter-axle differential with a limited slip.

Quadrajet

A spread bore carburetor, manufactured by Rochester, typically with two small primary venturii and two large secondary venturii. It was usually installed on General Motors engines.

qualify

To become eligible for a spot in a race by meeting speed requirements, and beating other drivers qualifying times, etc.

quench area

The quench area is the shallow, flat surface in the combustion chamber at the top of the piston at top dead center (TDC) used to push the air/fuel mixture towards the center of the combustion chamber for increased combustion temperatures and lower emissions.

R/T

Reaction time or light. This is the amount of time or delay incurred from the last yellow light on the Christmas Tree to the starting of the ET timer.

raking

The process of lowering the front end of a car in relation to the rear end.

RalliArt

Mitsubishi high performance division.

ram air

an air intake that channels the force of the air outside a moving vehicle into the air/fuel delivery system

RCE

Rotary Combustion Engine. This is a 4-cycle engine invented by German mathematician Felix Wankel. It differs from conventional engines by using a triangular rotor that revolves around the eccentric (shaft). The rotor stays in constant contact with the chamber walls and as it rotates it collects air, fuel, and spark. This action turns the crankshaft.

rear-steer

When the steering box and components are located behind the car's front axle.

reciprocating

Any motion that reverses itself, such as back-and-forth or up-and-down motion.

rectifier

a device that converts alternating current into direct current for an automotive electrical system

red-lighting

Leaving the starting line before the green light is activated and resulting in a foul start.

redline

(1.) The point where the engine develops its peak usable horsepower and rpm.
(2.) Also refers to the point on a tachometer that indicates maximum rpm.

relay

an electrical switch designed to carry large amounts of current, yet be activated by a smaller switch incapable of carrying a high current

restrictor plate

Racers running on high speed oval tracks are sometimes required to mount aluminum restrictor plates between the carburetor and intake manifold to limit the fuel and amount of air reaching the engine, slowing the car's top speed for safety reasons.

rheostat

a device used to vary the amount of voltage applied to an electrical unit

rich

See rich mixture.

rich mixture

A good air-fuel mixture for stock applications is 14.7 parts air to 1 part fuel (14.7:1). A rich mixture would have less air than that, say 13:1, which is a good mixture for race applications.

rim diameter

The diameter of the wheel measured from bead seat to bead seat.

rim flange

The inboard and outboard edge of the wheel rim that clip-on weights attach to.

rim width

The width of the wheel typically measured to bead seat from bead seat.

road rally

A group of people divided into teams competing in regular cars. Using everyday roads, and within legal limits they challenge themselves to achieve a certain distance and route within a specified time. The idea is not to be late or early, but to arrive on time.

rocker arms

Valvetrain components that "rock" back and forth as they are moved by the pushrods, opening and closing intake and exhaust valves.

roll bar

A tubular frame inside a passenger compartment or truck bed that protects the driver from being crushed if the vehicle rolls.

roll cage

A more extensive network of protective bars than a roll bar, usually welded to the frame in at least six locations for extra support.

roller cam

A camshaft designed for use with roller lifters

roller lifter

Lifters that have a wheel or roller on the camshaft end, that rolls on camshaft lobe faces. This allows the use of radical high lift cams, since the roller provides more surface to lessen the harsh impact of high rates of lift on the valvetrain.

rollers

Slang term for wheels.

round of bite

Describes the turning or adjusting of the car's jacking screws found at each wheel, and is used to distribute the car's weight at each wheel.

roundy-round

A slang term for an oval or closed racetrack, like Indy or Daytona.

rpm

Revolutions Per Minute. The amount of time(s) an object will orbit about a point within a minute. For example: When a vehicle is said to be at 2,500 rpm on the tach, it is the measurement of the crankshaft rotating 2,500 times a minute.

run-under

See break-out.

sandbagging

This is when a competitor dials-in an ET that is slower than the ET the car can run, so that you can hit the finish line before your opponent without breaking out.

SCCA

Sports Car Club of America. This is the largest road race sanctioning body in America.

scuffs

These are tires that have been previously used at least once. They are usually used in qualifying.

section height

The overall height of the tire sidewall measured vertically from the bead seat to the tread surface.

section width

The overall width of a tire from sidewall to sidewall.

sender; sending unit

a device mounted in the engine or fuel tank to convert mechanical properties to electrical signals for the purpose of operating electrical gauges

shaved

A slang term describing the removal of external vehicle parts, such as mirrors, door handles, and trim, in order to give the car a smoother, less cluttered appearance.

short track

A track under one mile in distance.

Showroom Stock

Category of SCCA Club racing that is for mass-produced street cars no more than five model years old, and with limited modifications (i.e. exhaust systems, steering wheels, brake pads, drivers seats). A roll cage and necessary safety equipment is required. This category is further divided into two classes: SSB and SSC.

shrink fit

A heating and/or cooling process for adapting a part or fitting that is slightly larger than the space available for it, resulting in an extremely tight fit.

Skyline

Refers to the Nissan Skyline GTR. It is a twin turbo, AWD coupe that is not sold in the U.S.

slammed

Slang term for an extremely lowered vehicle.

slick

(1.) This is a track condition where a car's tires can not get a good bite.
(2.) Special tires for racing, designed for maximum traction during hard acceleration and cornering. Slicks have no tread for maximum tire contact and feature a broad, flat surface of extremely soft rubber, which gets sticky when heated.

slider clutch

a multi-disc clutch designed to slip until a predetermined rpm, which decreases shock load to the drive wheels

slingshot

(1.) This is a maneuver in which the second car in a draft steers out from behind, the lead car, breaking the vacuum, to take the lead.
(2.) Dragster chassis with the cockpit behind the rear wheels, allowing a maximum percentage of the vehicles overall weight to be placed toward the rear for best possible traction.

Slip Angle

The angle of difference between the direction a tire tread is pointing and the direction the tire is actually going.

slug

A nickname for a piston.

solenoid

An electromagnetic spring with a metal core that converts electrical energy to mechanical energy.

Solo II competition

The term used by the SCCA to refer to autocrossing.

spoiler

A wing/blade mounted to the rear deck lid that uses air flow over the rear of the car to increase downforce for high speed stability.

sponsor

A business or individual who financially supports a race car, driver, or team.

spool

A one piece ring gear carrier that locks the rear axle shafts together and provides equal rotation of both wheels.

SSB

Class of Showroom Stock Club racing that is typically made up of entries like the Nissan 240SX, VW Golf VR6, and Neon coupes.

SSC

Showroom Stock Class. Class of Showroom Stock Club racing that is typically made up of slower vehicles than in the SB i.e. Mazda Protégé, Dodge Neon sedan, Honda Civic EX coupe, Nissan 200SX SE-R).

ST

Super Tuner. NIRA division of bracket racing for cars running 12.00-13.99, and they do not have to be an NIRA member to compete.

ST/1

Street Tuner 1. NIRA division of bracket racing for cars running 14.00-15.49, and they do not have to be an NIRA member to compete

ST/2

Street Tuner 2. NIRA division of bracket racing for cars running 15.50-up, and they do not have to be an NIRA member to compete.

stabilizer bar

See anti-sway bar.

stacks

Short exhaust pipes, or short air-ram tubes attached to the top of port fuel injectors or carburetors.

staged

When both the Pre-Stage and Stage lights are activated on the Christmas Tree.

stagger

When referring to bias ply tires only, the variation in a tire's circumference between the right and left side tires of the car.

stall speed

The approximate point at which the torque converter will couple or a point where the output nears the input.

stator

(1.) The bladed wheel of a torque converter that multiplies torque by redirecting transmission oil from the turbine to the impeller. The design of the stator greatly affects converter stall speed and efficiency.
(2.) Three stationary windings as part of an alternator that have overlapping pulses to smooth out current flow.

STI

Subaru Technica International. This is the high performance division of Subaru.

stick

(1.) Refers to a tire's traction.
(2.) Camshaft

stickers

New tires that still have the manufacturer's label on them.

Stock

Refers to an SCCA class of Solo II. This class consists of mass-produced vehicles able to be used for normal street driving, with minor modifications allowed (i.e. aftermarket shocks, wheels, tires, etc.).

Street Prepared

SCCA class of Solo II competition This class includes any Stock class vehicle with modifications to the suspension, ignition, intake, exhaust, and body (work to accommodate larger wheels and tires), but no internal modifications are allowed.

Street Touring

SCCA class of Solo II competition that allows sedans (four-seaters) with a maximum c.i.d. of 2.4L and naturally aspirated to compete.

stroke

The distance a piston travels within the cylinder. Also used to describe the process of increasing that distance, as in bored and stroked the engine.

stroker

An engine fitted with an altered crankshaft that has a larger stroke, increasing the engine's size without increasing the size of the block.

stroking

In NASCAR this is a driver that stays back in a race to not punish or wear out equipment before the end. Also called sandbagging.

subframe

used in the construction of unibody vehicles, where a full frame is not used

sulfation

When a conventional battery is left in a discharged state for an extended period of time and lead sulfate accumulations harden on the plates preventing the battery from recharging, or holding a charge.

supercharger

A pump device which forces air into an engine.

superspeedway

An race track with a mile or more of distance, this includes road courses. Racers have individual terms for the three types of oval tracks. First is a "short" track which is under a mile. Second is an "intermediate" track of at least a mile, but less than two. Finally a "speedway" is of two miles or longer.

sway bar

See anti-sway bar.

switchgear

(1.) Slang term for a shifter.
(2.) Also a term for switches (i.e. headlights, fog lights, heater controls, etc.).

T-1

Touring 1. SCCA Touring Category, this class allows for aftermarket wheels and open muffler and exhaust systems, as well as other options. No vehicle may be more than five years old.

T-2

Touring 2. SCCA Touring Category, this class also allows for aftermarket wheels and open muffler and exhaust systems, as well as other options. No vehicle may be more than five years old.

tappets

Another term for valve lifters.

TDC

The position of a piston at the end of an upward stroke.

tear offs

Clear plastic sheets covering a driver's helmet visor, designed to be removed when debris obscures view.

teardown

physical inspection of a vehicle by a race sanctioning body to ensure the vehicle meets class specifications; also used to describe dismantling an engine for a future rebuild

tech inspection

A pre-race inspection by track or race-sanctioning organization officials to determine whether a vehicle meets rule requirements.

terminal speed

The maximum or top speed achieved at the finish line.

throttle stop

a device that is preset to automatically decrease the throttle on a bracket racecar to keep the car under the dial-in

thrust button

Another term for a cam button.

tight

Term used when the front of the car has difficulty turning into the corners.

toe

The difference between the center front and center rear tire tread measurements. Tires leaning in toward the front are toed-in.

toe-in

A condition where the fronts of two tires on the same axle are closer together than at the rear

toe-out

A condition where the fronts of two tires on the same axle are farther apart than at the rear.

tonneau cover

A cover, usually vinyl, for the bed of a pickup truck, often attached with a series of snaps and braced with metal supports across the bed.

top dead center

The highest point of piston travel in the cylinder bore.

torque

The measure of active power that produces a twisting or turning around an axis. This is usually expressed in the measurement of foot-pounds or pounds-feet.

torque converter

This is a fluid-filled case used with an automatic transmission that consists of three main parts. The impeller, stator, and turbine are the main parts that work together to redirect fluid flow resulting in the multiplication of torque.

torque rating

The proper pressure to be applied when tightening and securing the wheel and tire assembly to the automobile with lug nuts. Torque is usually measured in foot-pounds.

torquing

Securing fasteners, such as wheel lug nuts or cylinder head bolts, to a specified pressure rating, usually measured in ft.-lbs. of pressure.

tour rally

This is a rally involving time, speed, and distance in the first leg, and then a straightforward course to follow. The challenge can be more driver or navigator oriented and points are awarded upon each category. Also termed as touring.

touring

See tour rally.

track bar

See panhard bar.

traction bars

a device used to control rear-end torque and stabilize suspension; also used to keep the front end of a racecar from lifting too high into the air

transmission blanket

a flexible wrap intended to contain parts in case of transmission explosion

TRD

Toyota Racing Development. The high performance division of Toyota.

tri-oval

This is a racetrack that has a fifth turn instead of the standard four.

tubbed out

A slang term referring to the installation of larger wheel wells so larger tires will fit under the car.

tuned header

A header with primary tubes of equal length.

turbine

The bladed portion of a torque converter that receives the flow of fluid to drive the disc and provide torque to the transmission.

turbocharger

A device which forces air into the engine. It features a turbine wheel driven by exhaust gases and connected to a compressor by a steel shaft. As the throttle is pressed, more exhaust is channeled to the turbine, causing it to spin faster, which in turn rotates the shaft and forces the compressor to move more air into the engine--creating more power.

Type R

Refers to the race version of a Honda or Acura.

underdrive pulley

A pulley (or set of pulleys) with a diameter smaller than stock to reduce the rpms of an accessory, reducing parasitic horsepower loss.

Understeer

A condition in cornering where the slip angles of the front tires are greater than the slip angles of the rear tires. This causes the vehicle to break traction and slide, pushing toward the outside of a turn.

unibody

Short for unit body, it is a vehicle structure that combines the frame and body into a single stressed unit for increased strength and lighter weight.

Unsprung Weight

The mass of vehicle components not supported by the suspension system.

valve lift

The distance a valve actually lifts from its seat.

valvetrain

The system of parts that controls valve movement, including lifters, pushrods, rocker arms, valves, and valve springs, located in the cylinder head.

vapor lock

Vaporized fuel in the fuel line or fuel pump caused by excessive heat. This creates a high pressure bubble that blocks fuel and stalls the engine.

venturi

A barrel of a carburetor, with a constricted throat that causes incoming air to speed up, creating a low pressure area, resulting in fuel vapor being drawn out of the carburetor bowl.

VIN

Vehicle Identification Number. The serial number issued by the OEM manufacturer to identify the model year and installed equipment of a particular vehicle.

viscosity

A measurement of a fluid's ability to flow at various temperatures, used frequently to rate motor oils. A higher viscosity fluid would be more resistant to flow than a lower viscosity fluid.

voltage regulator

an electronic device used to provide a uniform output of power to supply both a vehicle’s electrical system and keep the battery fully charged

volumetric efficiency

The actual amount of airflow into an engine compared to the theoretical maximum amount of airflow.

VTEC

VW

VWR

wedge

wedge, round of

weight jacking

weight penalty

wets

windage tray

wiring harness

a group of wires bundled together to connect any number of devices together electronically

WRCE

wrench

(1.) Slang term for a racing mechanic.
(2.) Also a hand tool used for tightening and loosening bolts, nuts, or other fasteners.

x-member

Y-block

y-pipe

A pipe with a "y" shape that merges two pipes or tubes into one. Commonly used in vehicle exhaust systems.

yoke

Z-car

zerk fitting

A fitting located on vehicle parts, particularly steering and suspension components, through which grease can be applied for lubrication. Also called a grease fitting.

zero lash

The point at which there is zero clearance between the cam lobe, lifter, pushrod, rocker arm, and valve stem, with no preload on the lifter.

zero offset