Production car racing

Production car racing, showroom stock racing, street stock, pure stock, touring and U-car racing are all categories of auto racing where unmodified (or very lightly modified) production cars race each other, outright and also in classes.

When the first oval speedway built for automobile racing was constructed in England in 1906, ordinary street cars were the vehicles of choice for racing. These cars were typically procured directly from dealerships, with minimal alterations made to meet the demands of the racetrack. The affordability and accessibility of stock cars allowed racing enthusiasts from all walks of life to participate, contributing to the growth and popularity of the sport.

As the sport evolved, so did the modifications made to the stock cars. Drivers started customizing their vehicles by enhancing performance and safety features, such as reinforcing chassis frames, installing roll cages, and improving engines and suspension systems. These modifications allowed the stock cars to withstand the intense demands of racing, turning them into formidable competitive machines.

These modifications increased the cost to compete, and in order to attract new competitors, race promotors responded by adding new divisions for "lesser modified" passenger cars. Requirements for these introductory divisions can vary greatly, but all are based on a full-bodied passenger vehicle and an original equipment manufacturer (OEM) production engine. Roll cages must be welded into the frame, and all glass, vinyl, upholstery and lights must be removed from the vehicle.

In various regions, they may be known as hobby stocks, street stocks, pure stocks, bombers, factory stocks or stingers. In British oval racing, the term "production car racing" has been used as an alternative for hot rods, as run in the West Country during the late 1960s to the mid-1970s, and a production car world championships. The West Country production cars were later reclassified as hot rods to come in line with the country's other promoters although this causes some confusion with the history of the West country racing as there was another class called hot rods that ran on those tracks.

The major U.S. sanctioning organizations – International Motor Contest Association (IMCA), DIRTcar, NASCAR, and Championship Racing Association (CRA/ASA) -- generally promote these classes as one of three levels: entry, intermediate, or advanced.

The Sport Compact (IMCA, DIRTcar) or Pure Stock (NASCAR) or Mini-Stock or Bomber divisions are the lowest entry-level racing class. Four-passenger vehicles with a four-cylinder or limited six-cylinder engines, the rules for these race cars mandate a stock body and a stock suspension. The vehicles can be made race ready for $500 to $2,000, and involve merely gutting the interior and adding a racing seat and roll cage.

The Hobby Stock (IMCA) or Factory Stock (DIRTcar) or Thunder Car (NASCAR) are also divisions designed to give new competitors the chance to go racing. The body and frame must match, and very few alterations are allowed to the stock frame and suspension. The engines produce roughly 300 horsepower and must reflect the correct pairing to the model. Racers can generally build competitive cars for between $3,500 and $10,000.