General Glossary
Acceleration: An increase in velocity or speed.
Acceleration squat: The tendency of the rear part of a vehicle to press down on the rear springs during hard acceleration.
Alloy: A metal containing additions of other metallic or nonmetallic elements to enhance specific properties such as strength and corrosion resistance.
Ambient air temperature: The temperature of the air that surrounds an object.
Analog instrument: An instrument having a needle on a dial used for taking measurements, such as temperature and engine RPM.
Anneal:
- A heating and cooling of steel in the solid state, usually requiring gradual cooling.
- To heat aluminum to 640°F (338°C) and then cool it to 450°F (232°C) to soften it to make it ductile.
Annealing: A heat-treatment process to reduce hardness or brittleness, relieve stresses, improve machinability, facilitate cold working, or produce a desired microstructure or property.
Anodize: A protective oxide coating to a metal surface using the metal as the anode in an electrical cell and allowing an electrolyte to act upon it.
Anti-seize compound: A thread compound designed to protect threaded connections from damage due to rust or corrosion.
Ballast: Material that is added to a racing car chassis to change the weight distribution and/or increase the overall vehicle weight to the minimum class requirement.
Barb fitting: A fitting that slips inside a hose and is held in place with a gear-type clamp or pressed-on ferrule.
Baseline: An initial reference point.
Bench test: The testing of an engine or component, out of the vehicle, for ease of observation and study.
Black flag: The signal for a driver to return to the pits for consultation with race officials.
Billet: A solid bar of metal.
Bolt on: An aftermarket accessory that can be installed without modification.
Boss: The reinforced extension on a part that holds a mounting pin, bolt, or stud.
Braze: A weld produced by heating an assembly to above 840°F (450°C) but below the solidus of the base metal.
Butt weld: A type of weld that joins two pieces of metal by fusion.
Calibration: The adjustment of a device or instrument so that output is within a designated tolerance for specific input values.
Case harden: A heat-treating process that hardens the outer surface of metal, while leaving the core soft and ductile.
Casting: A metal object formed to the required shape by pouring or injecting liquid metal into a mold.
Casting flash: A thin metal exuding at the parting edges of a casting mold, evident when the part is removed from the mold.
Casting number: A part number that has been cast into a part during manufacture.
Cast iron: A term used for a family of cast ferrous alloys containing at least 2% carbon, plus silicon and sulfur; may or may not contain other alloy elements.
Caution flag: A yellow flag displayed to race-car drivers to indicate a slow down. Also used to indicate no passing, due to a problem or mishap on the race track.
Centerline:
- To bore align.
- To blueprint.
- The axis of an object.
- Same as intake centerline when referring to a camshaft.
- A line indicating the exact center.
Chassis dynamometer (dyno): A drive-on device, used to measure net road horsepower and torque, delivered by the drive wheels.
Checkered flag:
- A flag waved at a driver, in closed-course competition, to indicate that he/she has completed the race.
- The first driver shown the flag is the winner of an event.
Check-valve: A valve that permits the passage of a gas or fluid in one direction, but not in the other.
Chicane: An artificial series of turns on a straight track, in road racing events, that are marked by pylons or temporary curbs.
Chrome molly (chromoly) steel: A steel alloy that contains chromium and molybdenum.
Circlip: A split-steel snap ring that fits into a groove, to hold various parts in place.
Clean room: An enclosed, ventilated or air-conditioned area, free of airborne particles where delicate components, such as engines and automatic transmissions, can be assembled with minimal risk of contamination.
Coefficient of friction: The measure of the resistance of one surface moving against another.
Curb height: The measurement from the vehicle frame to the road surface.
Curb weight: The weight of a vehicle ready for the road, with a full complement of fuel, oil, and coolant, but without cargo, driver, or passengers.
Diagnosis: A standard procedure that is followed to locate and identify the cause of a malfunction.
Diameter: The cross-section measurement of a round or circular object.
DOM tubing: An abbreviation for drawn-over mandrel tubing, a type of seamless tubing with precise and consistent inside and outside dimensions, used for race-car chassis construction.
Dowel: A pin inserted in an object or part to aid in the alignment of another object or part.
Dowel pin: A round, solid, or hollow pin used to align two or more parts.
Drift: A controlled slide through a turn involving all four wheels.
Dynamometer: A machine on which a vehicle may be driven, simulating actual driving conditions for emissions and diagnostic purposes.
Dyno: Short for dynamometer.
Early apex: Getting to the inside of a turn sooner than usual.
Efficiency: The output of energy divided by the input of energy, expressed in percentage.
Factory specs: Factory specifications; the manufacturer's dimensions, clearances, and tolerances.
Ferrous metal: A metal containing iron, such as steel.
Federation Internationale de l'Automobile (FIA): An international association of national automobile clubs that sanction and regulate major international auto racing series, such as Formula One.
Fitting: A hose end that is designed to mate with a mechanical part.
Flange gasket: A gasket that seals the mating surface of a flanged part and base surface.
Flange nut: A fastener that incorporates a flange or washer thrust surface.
Flapper valve: A ball valve that operates with a vacuum, pressure diaphragm, or motor.
Four-wheel drift: A controlled four-wheel slide on a paved surface.
G-force: The force that is exerted on a vehicle during acceleration, deceleration, or cornering, expressed in units of gravity (g's).
Grease: Lubricant consisting of a stable mixture of oil, soap thickeners (usually lithium, sodium, or calcium), and other ingredients for the desired physical or operating characteristics.
Grommet:
- A reinforced-metal eyelet through which a fastener is attached.
- A rubber or plastic eyelet inserted in a hole to protect wires that pass through it.
Gusset: A triangular piece of metal used to add strength to a corner.
Harmonic: The rhythmic vibration of a moving part or assembly.
Heat exchanger: An apparatus in which heat is transferred from one medium to another on the principle that heat moves to an object with less heat.
Heel and toe: The act of applying one's right toes to the brake pedal while applying the right heel to the accelerator to slow the vehicle as it enters a turn while keeping the engine revved up.
Heli-coil: A trade name for a screw-thread insert used to repair damaged internal threads.
High-pressure line: Any line or hose that carries high-pressure liquid or gas, such as a power-steering hose.
Homologated: A term used when a sufficient number of a particular car have been built to qualify them for racing as a stock-production vehicle.
Horsepower (HP): A measurement of mechanical power or the rate at which work is done.
Inertia: The property of a moving object that causes it to resist any change in speed or direction.
Keenserts: A trade name for a thread-repair system using spiral inserts to repair damaged threads.
Late apex: Getting to the inside of a turn later than usual due to a late entry into the corner.
Lateral acceleration: The centrifugal force that tends to push a vehicle sideways, toward the outside of a turn.
Lateral weight transfer: The momentary shift of a vehicle weight from the inside tires to the outside tires, or outside to inside, due to cornering forces.
Line pressure: The pressure present in a line or hose.
Linkage: A series of levers or rods used to transmit movement from one part to another part.
Lock nut: A nut that is designed to lock when tightened or torqued.
Lock washer: A split-type of washer that helps prevent a bolt or nut from working loose.
Low-pressure line: A hose or line used to carry low pressure vapor, liquid, or air.
Lubrication system: The oil pump, filter, hoses, lines and passages in an engine that facilitate the oiling of all moving parts.
Maintenance specifications: A listing of interval oil and lube grades, service points, and capacities for periodic and routine preventative maintenance service.
Mechanical efficiency: The percentage of input power as related to the output power in a mechanical transfer.
Molybdenum: An element (Mo) used in some steel alloys to add hardness and strength.
Motor vehicle: A machine, usually on rubber tires, that is propelled by means other than muscle power, and which does not operate on rails.
Net horsepower: The maximum engine horsepower as measured on a dynamometer.
Net torque: The maximum engine torque as measured on a dynamometer.
Octane: A gasoline's ability to resist detonation. The higher the octane number, the greater the fuel's resistance to detonation.
OEM: An abbreviation for original equipment manufacturer.
O-ring: A round ring having a square or round cross section used as a seal, such as at the end of a hydraulic line.
Power-to-weight ratio: The relationship of a vehicle's horsepower to its weight as given in horsepower per pound.
Powertrain: A combination of the engine, transmission, and final drive.
Preventative maintenance (PM): A systematic and scheduled inspection and service of a vehicle to ensure proper maintenance to provide a standard for satisfactory and sound operational conditions.
Pyrometer: An instrument used to measure high temperature.
Racer's tape: Duct tape.
R&R: An abbreviation for remove and replace.
Red flag: A signal for all drivers to come to a stop.
Repair order (RO): A written summary report of repairs that are requested or that are made.
Rivet: A fastener used to hold two pieces together.
Running gear: The undercarriage of a vehicle and all of the mechanical components attached to it.
Service bulletin: Technical service information provided by the manufacturer, used as updates for the service manuals and to provide the latest service tips, field repairs, product information, and other related information for the service technician.
Skid pad: A flat area of pavement with a painted circle 300 feet (91 meters) in diameter used to determine a vehicle's lateral grip and lateral acceleration.
Skunk works: A small, secretive group within the research and development department of a large organization that focuses on more advanced research and development.
Solidus: The highest temperature at which a metal or an alloy is completely solid.
Sports Car Club of America (SCCA): A major road-racing sanctioning body.
Stud: A round, bolt-like metal fastener with threads on both ends.
Technical service bulletin (TSB): The periodic information provided by the vehicle manufacturers regarding any problems encountered on current-year model vehicles.
Tensile strength: The maximum tension a metal can withstand without breaking.
Thou: A term used for thousandths, as in a measurement.
Thousandths: One part of a thousand.
Threaded fastener: Any of several types of components that hold parts together in assembly by interference of screw threads with mating threads in another component, such as capscrews, self-threading screws, stud-and-nut, and bolt-and-nut assemblies
Thrust load: Load placed on a part that is parallel with the center of the axis.
Thrust washer: A washer that is capable of supporting a thrust load.
Tolerance: The allowable variation from a standard specification.
Torque sequence: The order in which a series of bolts or nuts should be tightened.
Torque spec: The force required to tighten a nut or bolt.
Torque-to-yield bolt: A bolt that has been tightened to a specified yield or stretch point.
Torque wrench: A wrench that indicates the amount of torque being exerted when used, to enable threaded parts to be tightened a specified amount.
Torx fastener: A six-point fastener that is easy to grip and drive without slippage. Sometimes called a star fastener, this relatively new fastener is used on most late model cars in luggage racks, headlights, tail-light assemblies, mirror mountings, and exterior trim.
Traction: A body's friction on a surface such as a vehicle tire on a roadway.
Troubleshooting: The location of a problem or malfunction by a process of elimination.
Tungsten inert gas (TIG) welding: A welding process using tungsten (W) with an inert gas, such as argon (Ar), as a shield.
Unfair advantage: Not really unfair, the term given for that extra margin realized by a racing team with careful planning and attention to detail. Otherwise known as Quattro.
Unobtanium: A mythical alloy that is lighter, stronger, more flexible and, at the same time, more rigid than anything available.
Vehicle identification number (VIN): The vehicle's identification number, located on the left front of the dashboard, which represents various data such as the model of the vehicle, year, body, style, engine type, and serial number.
Velocity: The rate of motion in a particular direction.
Viscosity: The resistance of a fluid to flowing.
Viscous:
- Thick.
- Tendency to resist flowing.
Viscosity grade: The numerical rating of a fluid's resistance to flow.
Viscosity index: A number to indicate the change in viscosity of an oil when heated.
Yellow flag: A signal to drivers that there is a hazard on the track in closed-course racing.
Yield strength: The amount of force that can be applied to a material before it bends or breaks.
