Autocross
Autocross is a form of motorsports that emphasizes safe, low-cost competition and active participation. An autocross is a timed competition where drivers navigate one at a time through a temporary course marked by traffic cones, rather than racing on a track with multiple other cars, as in road racing or oval racing. Autocross tends to place more emphasis on car handling and driver skill than on sheer horsepower, and events typically have many classes which allow almost any vehicle, from economy sedans to purpose-built vehicles, to compete. Speeds are slower in absolute terms when compared to other forms of motorsports, usually not exceeding highway speeds, but the activity level (measured in driver inputs per second) can be higher than even Formula One due to the large number of elements packed into each courseTemplate:Fact. In addition to being a national-level motorsport in its own right, autocrossing is a great way to get started in road racing.
Autocross events are usually held in large paved areas like parking lots or airfields. Typically, new courses are created for each event so drivers must learn a new course each time they compete. Prior to driving, a competitor will walk the course, taking mental notes, and developing a strategy to be refined upon subsequent runs. National organizations such as the Sports Car Club of America (SCCA) and National Auto Sport Association (NASA) sponsor autocross events throughout the United States, and many areas have independent autocross clubs. Automobile manufacturers and their associated clubs (e.g. the BMW Car Club of America) sometimes hold marque autocross events.
Participation
The primary attraction of autocross is that it is a relatively inexpensive way to get involved in road-course-style motorsports. Because the lower average speeds, lack of physical obstacles and lack of wheel-to-wheel racing means that the potential for car damage, particularly from collisions, is very low, most autocrossers participate using vehicles based on production, road-going vehicles. It is not at all unusual to see an autocrosser race using his or her "daily driver." Many clubs use this aspect of the sport to try to attract new members by featuring classes for novice drivers.
The SCCA has ladies classes for autocross which share the same rules as the open classes but limit participation to women. It is common for husbands and wives, boyfriends and girlfriends, brothers and sisters or even two unrelated drivers to share the same car, but run it in their car's open class and its corresponding ladies class. The SCCA ensures that the ladies class for any given class is never run at the same time as the matching open class, specifically to allow car sharing in this manner. Women are not, however, prohibited from running in the open classes if they desire and many do so quite successfully.
Cars and Classing
Classes and rules vary from sanctioning body to sanctioning body, but typically the majority run lightly modified or unmodified (stock) vehicles. The most significantly altered production vehicles are the Street Modified cars, which retain production-based chassis but little else that is stock. Street Modified cars often produce in excess of 350 WHP, can reach 60 mph from a standing start in less than 3.2 seconds, and can corner in excess of 1.7 transient lateral Gs.
There are usually classes for purpose-built race cars imported from other series (including Formula Fords, Formula Atlantics, Formula 500s and vehicles similar to American oval-track stock cars) but most autocross cars are based on production cars.
The very fastest autocross cars are purpose-built "specials" (Modifieds in SCCA parlance) that feature huge, multi-element wings, snowmobile engines, and CVTs. While their top speeds are typically limited by gearing and the enormous aerodynamic drag from the huge wings, their transient cornering capabilities are unparalleled in motorsport.
Related Motorsports
In the United States the sport described here is commonly known as autocross (it is also known as "Solo," the SCCA's brand name for it) but other regions of the world have different names for it. Certain parts of Canada and Eastern European countries (Russia, Ukraine, Moldova), for instance, call it autoslalom. In the United Kingdom it is known as SoloMotorsport or autosolo and autocross refers to a similar sport that is held on unpaved surfaces like grass and dirt (also see SCCA RallyCross). In Southeast Asia, countries like Malaysia and Thailand refer to the sport as autokhana.
Motorkhana (as it is known in Australia and New Zealand) and autotesting (UK and Ireland) are related sports. With speeds rarely exceeding 40 mph (60 km/h), both motorkhana and autotesting are slower than American autocross, require handbraking, and have sections that must be negotiated in reverse. On the other hand, autocross speeds can reach over 60 mph (100 km/h) and courses that would require the driver to enter reverse are generally prohibited in autocross. Handbraking is also not usually necessary on a typical autocross course.
These are similar to the Japanese gymkhana, another type of handling competition. Gymkhanas are even tighter than motorkhanas and autotests, with numerous 360-degree turns around cones and courses that loop back upon themselves. Fast times require a lot of sliding and the end result ends up looking similar to a cross between autocross and drifting. Gymkhanas do not usually require entering reverse gear.
In ProSolo, an SCCA-sanctioned variant of autocross, two cars run side-by side on mirror-image courses after starting at a "christmas tree" starting system similar to that used in drag racing.