In the 1920s, moonshine runners during the Prohibition era would often have to outrun the authorities. They had to upgrade their vehicles while leaving them looking ordinary. Eventually, runners started getting together and making runs together, challenging one another and progressing to organized events in the early 1930s. The main problem racing faced was the lack of a unified set of rules among different tracks. When Bill France Sr. saw this problem, he set up a meeting at the Streamline Hotel in order to form an organization that would unify the rules.
When NASCAR was first formed by France, Sr. in 1948 to regulate stock car racing in the U.S., there was a requirement that any car entered be made entirely of parts available to the general public through automobile dealers. Furthermore, the car models were required to have sold over 500 units to the public. This is referred to as "homologation". In NASCAR's early years, the cars were so "stock" that it was commonplace for the drivers to drive themselves to the competitions in the car that they were going to run in the race. Until the advent of the Trans-Am Series in 1967, NASCAR homologation cars were the closest thing that the public could buy that was actually very similar to the cars that were winning national races.
The 1949 Oldsmobile Rocket V-8 is widely recognized as the first postwar modern overhead valve (OHV) engine to become available to the public. The Oldsmobile was an immediate success in 1949 and 1950. However, the aerodynamic and low-slung Hudson Hornet managed to win in 1951, 1952, and 1953 with a 308 cu in (5.0 L) inline six-cylinder that used an old-style flathead engine. In 1953, NASCAR recommended that drivers add roll bars, but did not require them. In 1957, the Automobile Manufacturers Association banned manufacturers from using race wins in their advertising and giving direct support to race teams.
The desire from fans and manufacturers alike for higher performance cars within the restrictions of homologation meant that carmakers began producing limited production "special edition" cars based on high production base models. For the 1963 season NASCAR engines were restricted to using a maximum displacement of 7.0 liters (427 cu.in.) and using only two valves per cylinder. In 1963 Ford sold enough of their aerodynamic "sport-roof" edition Galaxies to the public so it would qualify as stock, and with the heavy-duty FE block bored and stroked to the new limit of 427, the top five finishers were all Fords. Chrysler had bored their 413 to create the "Max Wedge" 426, but it still could not compete with the Fords.
In 1965 Ford adapted two single-overhead-cams to their FE 427 V8 to allow it to run at a higher RPM (called the Ford 427 Cammer). Ford started to sell "cammers" to the public to homologate it, but NASCAR changed the rules to specify that all NASCAR engines must use a single cam-in-block. In 1966 Chrysler sold enough of the 426 Hemis to make it available again, and they put it in their new Dodge Charger which had a low-drag rear window. Richard Petty dominated 1967, winning 27 of 48 races (including 10 in a row) in the boxier Plymouth Belvedere.
The 1969 season featured the Torino Cobra or Torino "Talladega" which had enough aerodynamic body improvements that it gave it a higher speed than the 1968 Torino, with no other changes. Richard Petty signed a lucrative deal with Ford after a private viewing of Ford's new Talladega and Boss 429 engine. Prior to its first race at the Daytona 500, David Pearson's 427 powered Ford Torino Cobra set a new NASCAR record by being the first to exceed 190 mph (310 km/h). With Ford winning the majority of the races, Dodge was forced to develop a better car of their own. They named it the Dodge Daytona after the race they hoped to win.
NASCAR feared that these increasing speeds significantly surpassed the abilities of the tire technology of the day. As a result, the 1970 Homologation rules were changed so that one car for every two U.S. dealers had to be built for sale to the public to qualify. For the 1970 season Dodge raced the 1969 model Daytona, but Plymouth managed to build over 1,920 Plymouth Superbirds. Petty came back to Plymouth in the plus 200 mph (320 km/h) Superbird, and Bobby Isaac won the season championship in a Daytona. NASCAR restricted all "aero-cars" including the Ford Talladega, Mercury Spoiler II, Charger 500, Dodge Daytona and Plymouth Superbird to a maximum engine displacement of 305 cu in (5.0 L) for 1971. NASCAR eventually adopted a restrictor plate to limit top speeds for the 7.0L engine as teams switched to small-block 358 cu in (5.9 L) engines.
In 1972, R.J. Reynolds took over as the major sponsor of NASCAR racing, changing the name to the "Winston Cup". Richard Petty's personal sponsorship with STP also set new, higher standards for financial rewards to driving teams. The 1973 oil crisis meant that large displacement special edition homologation cars of all makes were suddenly sitting unsold. From the 1970s until 1991, the factory stock sheetmetal over a racing frame meant the cars looked very much like their street version counterparts. Modern racing "stock" cars are stock in name only, using a body template that is vaguely modeled after currently available automobiles.
A stock car, in the original sense of the term, is an automobile that has not been modified from its original factory configuration. Later the term stock car came to mean any production-based automobile used in racing. This term is used to differentiate such a car from a "race car", a special, custom-built car designed only for racing purposes. Today most American stock cars may superficially resemble standard American family sedans but are in fact silhouette cars: purpose-built racing machines built to a strict set of regulations. For example, NASCAR Cup Series race vehicles now require fuel injection.
"True" stock car racing, which consists of only street vehicles that can be bought by the general public, is sometimes now called "street stock", "pure stock", "hobby stock", "showroom stock", or "U-car" racing. In 1972, SCCA started its first showroom stock racing series, with a price ceiling on the cars of $3,000. Super stock classes are similar to street stock, but allow for more modifications to the engine. Power output is usually in the range of 500–550 horsepower (373–410 kilowatts).
Modified stock cars resemble a hybrid of open wheel cars and stock cars. The rear wheels are covered by fenders but the front wheels and engine are left exposed. First popular in the United States after World War II, this type of racing was early-on characterized by its participants' modification of passenger cars in pursuit of higher speeds. NASCAR officially sanctions the NASCAR Whelen Modified Tour which is the oldest racing series sanctioned by NASCAR.
In many areas of the country late models are usually the highest class of stock cars in local racing. Rules for construction of a late model car vary from region to region and even race track to race track. The most common variations (on paved tracks) include super late models (SLMs), pro Late models (PLMs), late model stock cars (LMSCs), and limited late models (LLMs). Individual sanctioning bodies (like NASCAR, ACT, PASS, UARA, ASA, CARS Tour, etc.) maintain their own late model rule books.
NASCAR is currently the largest stock car racing governing body in the world. While NASCAR sanctions multiple series, it has three national championship touring series that are commonly referred to as the "top 3" series. In addition to the top three series, NASCAR also sanctions many regional and local series. NASCAR also sanctions three international series that race in Canada, Mexico, and Europe.
The most prominent championship in stock car racing is the NASCAR Cup Series. It is the most popular racing series in the United States, drawing over 6 million spectators in 1997. The most famous event in the series is the Daytona 500, an annual 500-mile (800 km) race at the Daytona International Speedway. The series' second-biggest event is arguably The Brickyard 400, an annual 400-mile (640 km) race held at the Indianapolis Motor Speedway.
The NASCAR O'Reilly Auto Parts Series is the second national series in the United States. It serves as the primary feeder series to the Cup Series, similar to Formula Two for Formula One. Races are commonly held as a support race to Cup Series events. Many current Cup Series drivers formerly competed in the Series before moving on to competing full-time in the Cup Series.
Starting in 1995, the NASCAR Truck Series is the third highest ranking stock car series in the United States. The series was the brainchild of then-NASCAR West Coast executive Ken Clapp. Unlike the other two national touring NASCAR series, the Truck Series race pickup truck styled bodies, though it is still considered a stock car series because of its similarity.
The Automobile Racing Club of America was founded in 1953 as a Midwest regional series. In addition to the ARCA Menards Series, it formerly sanctioned the ARCA Midwest Tour, and the ARCA Lincoln Welders Truck Series from 1999 to 2016. NASCAR purchased ARCA in early 2018. For the 2020 season, the NASCAR K&N Series East and West were rebranded under the ARCA banner as the ARCA Menards Series East and ARCA Menards Series West.
Canada, Mexico, Brazil, Argentina and Chile also have forms of stock car racing in the Americas. Other countries, such as Australia, New Zealand and the United Kingdom, have forms of stock car racing worldwide as well. Internationally, stock car racing has not enjoyed the same success as within the United States and Canada. Brazil also has a successful stock car racing series, with starting grids of 30 or more cars, and two brands competing: Chevrolet and Toyota. Brazilian Stock Car also has two developing series. Despite the name, Brazilian stock car competitions are not held on oval tracks, thus they resemble more touring car racing than stock car racing. The same can be said about Argentina's popular stock series, called Turismo Carretera.
Stock car races take place predominantly on oval tracks of 3 or 4 turns, with all turns to the left. Oval tracks are classified as short track (less than 1 mile), intermediate or speedway (1 to 2 miles) or superspeedway (over 2 miles). Road courses are any tracks having both left and right turns. Depending on the track, typical race speeds can vary from 90 miles per hour (140 km/h) at Martinsville to over 200 miles per hour (320 km/h) at Talladega. In 1987 Bill Elliott's 212.809 mph (342.483 km/h) qualifying time at Talladega brought about a change at superspeedways (Daytona and Talladega). Such high speeds and Bobby Allison's car going airborne into the catch-fence and injuring fans forced NASCAR to implement power-reducing measures, one of which was the mandated implement of below carburetor restrictor plates. This later became known as restrictor plate racing.
In contrast with most forms of racing, minor car-to-car contact is generally accepted in stock car racing. This may happen in the form of forcing another vehicle out of the way, or pushing a competing vehicle forward for mutual benefit. On intermediate tracks and superspeedways, drafting is used to reduce the overall effect of drag. A driver accomplishes this by positioning the vehicle close to the one ahead of so as to benefit from the other's slipstream. Drafting was "discovered" by Junior Johnson during his winning performance at the 1960 Daytona 500.
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