a glossary of driving terms


4WD Four wheel drive

ABS Anti-lock Braking System

Acceleration The change of velocity per unit time. It has both a direction and a magnitude. Acceleration in the direction opposite of the velocity is commonly called deceleration.

Apex (noun) The point in a turn where the car comes the closest to the inside of the track. see clipping point

Apex (verb) To cause the car to come to the inside edge of the track

Armco, Metal barriers.

AWD, All Wheel Drive

Bench racing Talking about racing. The stories are usually loosely based on fact.

Berm  Concrete curbing at the edge of the track.

Botz dot The little reflector dots between lanes on public roads.

Brain Fade Not paying attention to what you are doing. Spacing out.

Braking point The point at the entrance of the turn at which you first apply the brakes.

CCR Club Codes and Regulations. The N.A.S.A. rulebook.

Centrifugal Force Something that physicists will tell you doesn't really exist. The inertia of a car wanting to go straight will seem to force a car to the outside of the turn. It doesn't really want to go away from the center, just straight.

Clipping point Where your inside wheels touch the inside edge of the track.

Circle of friction A concept used to explain the traction abilities and limitations of a car. There is a finite limit to the vector sum of the forces a tinore can apply betwen the car and the road.

Coefficient of friction The ratio between the sideways force generated by an object and the vertical force applied to it.

Confidence lift Briefly lifting the throttle off of the floor at the entrance of a turn. The foot is lifted and replaced just about as fast as possible. The primary effect on the car is to put a little extra weight on the front wheels to aid in turn down. It is usually really done because the driver's subconcious doesn't think he can make the turn without slowing down. Hence the name, it gives the subconcious confidence without greatly slowing the car.

Defensive line The fastest path around a turn that safely makes it difficult for someone to pass. It differs from the qualifying line by entering the turn a little less than a car width from the inside.

Dicing Competing for position.

Downshift Putting the transmission into a lower gear so the engine will turn faster at the same road speed.

Dragons Teeth, (no-no's) Short berms with small bumps or ridges in them that discourage driving on them.

Drift Exiting a turn with all four tires in a controlled slide. Often the steering wheel is straight, the car is aimed down the straight and throttle is full on. The centrifugal force carries the car to the outside of the track.

Driver's Left The left side, as seen by a driver facing the proper direction on a race track.

Driver's Right The right side, as seen by a driver facing the proper direction on a race track.

Early apex An apex before the geometric apex. This will leave you pointing at the outside of the track on the exit of the turn. In this case you will have to either slow down and turn the steering wheel more, or exit the track.

Ergonomics The study of making things easy and comfortable for people to use.

FIA International automobile racing sanctioning body

FIA curbing Red and white cement berms placed at the apex and exit of turns. These keep the edge of the asphalt from crumbling from drivers driving off of the edge ot the track.

Flat As in "taking it flat out". Keeping the throttle flat on the floor. Not braking or even lifting.

Flat spot (verb)Wearing a flat spot into the tread of a tire, sometimes all of the way to the belts. Usually done by spinning the car, or locking up the brakes.

Formula car An open-wheeled race car. Indy and formula one cars are well known examples.

Full lock Turning the steering wheel to the full extent of its travel.

FWD Front-wheel-drive

G.C.R. General Competion Rules. The rulebook for roadracing in the Sports Car Club of America (SCCA).

Geometric apex Halfway around a turn. If you were to draw an arc of the largest possible radius through the turn, the "apex" would be in the middle of the turn. You only apex at this point on very high speed turns when you don't need to slow down and want to maintain the maximum speed through the turn.

Horsepower A measure of energy per unit of time, equal to 745.7 watts. Also directly related to torque multiplied by rpm.

Hot-pits An area next to the track where work can be done on the car during a track session.

I.C.S.C.C. (the Conference) International Conference of Sports Car Clubs, a race sanctioning body active in the Pacific Northwest.

I.M.S.A. International Motor Sports Association, a race sanctioning body.

Late apex An apex after the geometric apex. Allows an exit from the turn with less steering and more acceleration.

Lateral acceleration A measurement of how fast something is going around a turn. Measured in g's., one-g being the acceleration of a falling object at sea level in a vacuum.

Line The path taken around either a turn or a race track.

Lockup When the brakes are applied so hard that the wheels stop turning.

Loose Oversteer.

Marbles The little balls of melted rubber from race tires that collect on the outside of turns. If you drive from the line into the marbles, you will find yourself suddenly losing traction.

N.A.S.A. National Auto Sport Association, a race sanctioning body.

Oops A comment often made just before an expensive lesson in the laws of physics.

Opposite lock Turning the steering wheel the opposite direction that the car is turning. If the car is oversteering around a right hand turn, turn the steering wheel to the left to regain control. This points the front wheels in the direction the car is heading, even if the rear wheels are pointing 90 degrees from the direction of travel.

Overcook To enter a turn "too hot" (too fast). Rather than making a smooth line out of the turn, you end up having to scrub off speed during the turn, or worse, go off course.

Oversteer What scares the passenger. What causes the rear end of the car to hit the wall. When the rear end of the car loses traction. When the car turns more than it should.

Pauli Principle (or Pauli Exclusion Principle) Two electrons with the same spin cannot occupy the same orbit. Attempts to violate this principle on the track are expensive and pointless.

Performance Driving Driving a car in such a manner as to not only use more of it's performance capabilities than one would (or should) on the street, but so as to require more skill and technique. Unlike racing, it is not competitive, and some margin is left so as to minimize the chance of an "Oops" where the car attempts to violate the Pauli Principle.

Plow, Understeer.

Pre-grid The place to wait in your car before going out on track.

Push, Understeer

Qualifying Line The fastest line for a solitary car to drive around a race track.

RWD Rear-wheel-drive

Red Mist The condition where ego or testosterone poisoning overcomes one's knowledge of one's mortality. Generally entered when a driver is passed, or sees a faster car ahead to try and catch. Results in missed flags, embarassment, and an oops at worst.

RCH A traditional machinists unit of measure. A very small amount, less than can be accurately measured.

m  RCU Race Car Unit, $100. The smallest quantity of money that ever seems to be spent at one time on a race car.

RPM Revolutions per minute, a measurement of engine speed.

S/F The start-finish line.

School line A fast yet safe line around the track taught to beginning drivers. Usually very similar to the qualifying line with later apexes.

Shortshifting Upshifting at a lower RPM than usual.

Skid When the car is moving, but the tires are not rolling in the direction of travel. The brakes could be locked up, or the car is not facing the direction it is heading (oversteer), or the front wheels are turned and the car is still going straight (understeer).

Slicks Tires specially made for racing that have no grooves cut into the tread. Much softer and stickier than street tires, but hazardous under wet track conditions.

Slip angles The difference between the direction a tires is pointing and the direction it is going.

Smoothness No discontinuities in the higher order derivitives of the cars velocity and acceleration.

Spin, loop When the car achieves more than 90 degrees of oversteer. In other words, it goes into a skid in which the back of the car passes the front of the car.

Sports Racer A purpose built race car, where the tires are enclosed in the body work. The Can-Am series and Le Mans racers are well known examples.

Stuffing the car What often happens immediatley after and pursuant to an Oops.

Surface flag The red and yellow flag. Also called the oil flag. There is something on the racing surface.

Target fixation Concentrating so hard on something you don't want to hit, that you drive right into it. Remember, you tend to steer where you are looking.

Threshold braking Braking just on the verge of lockup.

Throttle steering Adjusting your line through a turn by increasing or decreasing the throttle, rather than turning the steering wheel.

Tight (Also low or inside) On the inside of a turn

Torque Force times Distance. A 10 pound force on a 1 foot lever will generate the same torque as a 1 pound force on a 10 foot lever.

Trailing throttle oversteer (see Porsche) An oversteer condition caused by lifting off of the throttle in a turn. Tail heavy cars are very prone to this.

Turn down point The point at which you turn the steering wheel at the entrance of the turn.

Turn-in turn down

Understeer What scares the driver. What causes the front end of the car to hit the wall. When the front end of the car loses traction. When the car turns less than it should.

Upshift Shifting the car into a higher gear so that the engine will turn slower at the same road speed.

WFO Full throttle.

Wide (also high or outside) The outside portion of a turn.

Copyright (C) 2003 Larry Colen
Most recently modified by lrc at Wed May 28 09:57:18 PDT 2003