Want to learn the lingo of an autocross event?  Here is a list of the most common autocross terms.

  • Apex: The point of a corner where your car should be placed closest to the inside of the turn, this is the point in the corner where you go from asking the car to turn to unwinding the wheel and allowing the car to complete the corner.
  • Adjustable Shocks: Adjustable shocks are allowed in all forms of autocross competition. The downward force adjustment is referred to as compression, while the upward is referred to as rebound. Some shocks allow for adjustment in both directions, known as double adjustables or DAs while others are single adjustables or SAs.
  • Backside: Refers to the back of a cone. Generally, when autocrossers are talking about the backside, they mean placing the car in the space directly behind the cone to allow for the maximum amount of space to position properly for the next element.
  • Camber: refers to the angle of either a wheel or the ground. Ground camber is a note of the slope either toward or away from an apex. Wheel camber indicated the amount a wheel is angled up and down. For autocross, more camber is better as it reduces tire wear and increases grip.
  • Chicago Box: A short slalom disguised as a box.
  • Chief Steward: The Chief Steward serves as the head referee for an autocross. They make final decisions on re-runs, changes, and accept any complaints or protest from competitors.
  • Clean Run: Indicated that a run through the course was without penalty.
  • Course Designer: The individual charged with the task of laying out the course at an autocross.
  • Course Worker: Someone whose work assignment is on the course. Course workers reset cones, call in cone strikes on the radio, and display red flags as needed.
  • Decreasing Radius Turn: Where the radius of your turn gets tighter as you go through it. Usually requires a decrease of speed to exit properly.
  • Dirty Run: A run where a cone was hit, or there was an off course.
  • DNF: Did Not Finish. A run is scored as a DNF when a portion of the course was not completed. DNF runs do not post a time.
  • DNS: Did not Start. A run is scored with a DNS if the driver is unable to or elected not to start the run.
  • DSQ: A run is scored as a DSQ, if the run or driver is disqualified for any reason.
  • FTD: Fastest Time of the Day
  • FTP: Fastest Time PAX - The fastest time in an event, once times are adjusted for class potential using the Racer's Theoretical Performance index, often known as RTP or PAX.
  • Gate: Two cones, arranged for you to drive through them.
  • Grid: The staging area for cars within a run group. There may be an active grid for cars currently running and a pregrid for cars in an alternate run group, or a single grid that everyone works from. There are specific rules and procedures for things like working on cars in the grid areas.
  • Increasing Radius Turn: Where the radius of your turn gets wider as you go through it. Usually allowing you to increase speed on corner exit.
  • Late: Being or getting late refers to becoming behind in the course flow. A driver who is late does not have time to get set up before they arrive at the next element.
  • Late Apex: The act of turning your car toward the apex as late as possible.
  • Modified: Modified Classes are for purpose built race cars, or cars that have been modified beyond the rules of Prepared Classes. There are Modified Classes for both formula cars and sports racers and for productions based cars as well as a class for 125cc shifter karts.
  • National Tour: Tour events are part of the Tire Rack SCCA National Series. They mimic the format of SCCA SOLO Nationals and are designed to give competitors an opportunity to face top-level competition and practice the championship format during the year.
  • NOC: Not Otherwise Classified. A term used to indicate a catch-all of a car makes and models that do not have specific classifications elsewhere.
  • Off Camber: When the surface tilts away from the inside of the turn. This causes the car to lose grip keeping the cornering speeds lower.
  • Offsets: A series of gates or stand-alone cones that must be driven through or around where the orientation is not in alignment. Offsets are often used to control speed on what would otherwise be a straightaway.
  • On Camber: When the surface tilts toward the inside of the turn. Such as the bankings you see at the super-speedway. This allows for more grip thus allowing you to take the turn slightly faster.
  • Op Steward: The Op Steward (or Operating Steward) is responsible for the flow of an event. Op Stewards ensure there are cars coming from the grid to the start line, that the course is ready and that workers are in position.
  • Oversteer: A handling condition where the car wants to turn too much. The key characteristic of oversteer is the back end of the car losing grip and sliding out as is common in drifting. Extreme oversteer results in spinning out.
  • Novice: General term in Autocross for anyone in their first few events. Many regions have novice classes for new drivers to compete in and offer novice schools.
  • Paddock: The area where cars, trucks, trailers and spare equipment is kept during the day.
  • PAX: Stands for Professional Autocross. PAX was a method of scoring cars from a wide variety of classes by applying a multiplier to their times. The PAX factor has been replaced by Racer's Theoretical Performance index (RTP) but the term PAX is still informally used to reflect the process.
  • Pin Turn: Term for a tight, 180-degree turn, where a single cone, known as a pin cone, marks the apex.
  • Plus 1 (+1): Term to indicate that a cone was hit on a run. It stems from the announcer stating the time, and then adding "plus 1."
  • Pointer Cone: Pointer cones, or directional cones are used to indicate which side of a stand up cone the course is routed on. These cones lie on their sides, and serve as arrows pointing to the opposite side of the cone. Pointer cones are not scored, should one be hit during a run.
  • Prepared: Prepared classes are for cars that have been fully prepared for motorsports competition. Interiors may be removed, along with accessories, lights, and glass. Engines may be built, bodywork may be modified and racing only tires may be used. There are 5 prepared classes, one of which, X-Prepared allowing more radical modifications such as engine swaps and forced induction.
  • ProSolo: A specific format of autocross that combines elements of drag racing at the start. After the side-by-side Christmas tree start, competitors enter separate, mirror image courses. ProSolo is a part of the Tire Rack SCCA National series, though there are regions that host their own ProSolo style events.
  • Racer's Theoretical Performance (RTP): RTP is an indexing system that is designed to balance the performance of all classes. It does so by multiplying a driver’s time by a factor. For example, a time of 60.000 in a fast class would be multiplied by .950 for an index time of 57.000. A driver in a slower class, where the index is .900 who turned a time of 62.000 would have an index time of 55.800. Thus the driver in the slower class, despite having the slower course (or “raw”) time, met more of their class's potential, and thus has a better indexed time.
  • Race-Compound (R-Comp or R-Compound): A tire that meets Department of Transportation (D.O.T.) approval, but is considered to be for racing purposes only. These tires generally have very shallow tread depth, extremely sticky rubber and are extremely high performance potential.
  • Race Tire (Slicks): a term referring to tires that are not approved by the D.O.T. and not legal to be driven on the street. These tires have no tread pattern what so ever and are intended strictly for racing purposes. Race Tires are only allowed in Prepared and Modified classes.
  • Raw Time: The unadjusted course time for a driver. Raw time does not take into account penalties or indexing.
  • Red Flag: Every corner station on an autocross course has a red flag. If you see one on a run, simply bring your car to a stop. Generally red flags are displayed when a car ahead of you has spun or stopped on course.
  • Re-Run: When a driver is shown a red flag or there is an issue with the timing or scoring of a run, a re run will be granted. Re-runs may also be granted if a driver stops for a downed or out of place cone, or because of course workers.
  • Safety Steward: Safety Stewards are licensed event officials that oversee the execution of the event with regard to safety. They approve the course, evaluate event flow and handle any paperwork that may need to be done.
  • Set Up: The act of getting ready for the next element on a course. Typically setting up for something involves a specific car placement or speed adjustment.
  • Slalom: A common course element, taken from downhill skiing. A slalom is a line, generally straight, of cones that must be weaved through. Some slaloms are optional, meaning you can start on either side of the first cone.
  • SOLO: SOLO is the SCCA brand name for Autocross.
  • SOLO Nationals: The SCCA national championship event, held annually in Lincoln Nebraska. SOLO Nationals is the largest motorsports competition in the world, with over 1100 drivers each year. The format of SOLO Nationals is a two-day event, with 3 runs on a separate course each day. Nationals itself is a weeklong event with half the classes competing on Tuesday and Wednesday, and the other half on Thursday and Friday.
  • Staging: The area before the starting line, or the act of placing the car at the starting line.
  • Street Tires: Street tires are generally tires that were not expressly created for motorsports. Many competitors elect to compete on street tires in a variety of classes. For example, they are mandated in the Street Touring (ST) Category. Street tires generally have greater tire life though less grip than a R-Compound tire.
  • Street Modified: Street Modified is a newer category. It's intent is to give competitors who want to build motor swapped, supercharged and turbocharged cars a place to play, while keeping the basic suspension, interior and chassis properties of the car from the factory. The competitiveness of cars is balanced by having minimum weights, based upon displacement and induction system. These cars still must maintain the appearance of road going vehicles, but they generally are race only vehicles. There are 3 classes in the Street Modified Category, one for 2 seaters, one for rear and all wheel drive sedans and one for front wheel drive cars. Street Modified cars are the fastest cars in autocross that run on D.O.T. approved tires.
  • Street Prepared: Street Prepared allows more modifications that Street Touring as well as R-Compound tires. Competitors are allowed to build "best of" cars that take the best parts from a variety of years and combine them on a single car. Some level of engine preparation is allowed. Racing seats and steering wheels are allowed, however interiors, lights and road going equipment must be retained. There are 7 Street Prepared Classes, with cars classed based on ultimate potential rather than configuration.
  • Street Touring: Street Touring is the newest classing category. The rules allow for basic suspension modifications such as coilovers, sway bars, bushing and camber bits. There are some allowed power adders such as headers and intakes and ECU modifications, but engines and transmissions must remain stock. Tires in Street Touring are limited to true street tires, treadwear rated 140 or higher. Seats may be substituted for competitions seats, but other interior components and road going equipment must remain stock. There are only 5 classes in the category, 3 for sedans and hatchbacks and 2 for traditional 2 seat sports cars.
  • Street: Street Category is for cars straight off the showroom floor with only a handful of modifications allowed. Competitors are allowed to run performance shocks, a non-stock sway bar on either end and cat back exhaust. Standard wear items can be substituted, such as brakes. Any D.O.T. approved tire with a wear rating of 200 or higher is allowed. There are 9 steet classes.
  • Sweeper: A long wide corner that you can generally carry a lot of speed through.
  • Toe: Toe is the alignment setting that determines the angle of the wheel front to rear. It can be measured in total toe, indicating the total amount of angle between both sides, or for the single corner. Toe out in the front can give a car quicker steering feel. Toe-out in the rear can help a car initiate a turn, while rear toe-in can reduce oversteer.
  • Trail Braking: Continually applying pressure on the brakes to keep the weight of the car off the rear end to endues an easier rotation.
  • Understeer: A handling condition where the car does not turn enough. Commonly referred to as push, understeer is generally caused by entering a corner with more speed that the front tires can handle, or by applying more throttle in the middle of the corner than can be handled in a front wheel drive car.
  • Worker Chief: The event official charged with the task of assigning competitors a work assignment. Typically it is the responsibility of the competitor to check in with the worker chief before reporting to their assignment.

To request a term be added to the Tire Rack SCCA Autocross Glossary, please email: heyward@sccastartingline.com