Pro Stock

Pro Stock is a class of drag racing featuring high-performance cars that look like street vehicles but use powerful naturally aspirated engines without turbochargers, superchargers, or nitrous oxide.

The Pro Stock class emerged in 1970 from an earlier category called super stock. Racing officials created this new class with more flexible rules, allowing teams to modify their cars more extensively while still maintaining a factory appearance. These vehicles are often called "factory hot rods" because they blend the look of production cars with professional racing performance.

What makes Pro Stock unique is the "all motor" approach. Unlike some other drag racing classes, Pro Stock cars cannot use forced induction systems like turbochargers or superchargers to boost power. They also cannot use nitrous oxide injection. All the horsepower comes purely from the engine's natural breathing capability, which makes the engineering achievements even more impressive.

Pro Stock engines are restricted to a maximum size of 500 cubic inches (8.2 liters) and must be 90-degree V8 engines with a single camshaft. Despite these limitations, modern Pro Stock engines produce upwards of 1,500 horsepower through naturally aspirated power alone. These engines can use either traditional four-barrel carburetors or modern electronic fuel injection systems.

The cars themselves must weigh at least 2,350 pounds including the driver. While the bodies are molded from lightweight carbon fiber and designed to look like street cars, underneath sits a full tube chassis built specifically for racing. The wheelbase must measure between 105 and 109 inches, and the cars use automotive-style suspension systems rather than specialized drag racing setups.

A competitive Pro Stock car can complete a quarter-mile run in approximately 6.4 seconds while reaching speeds over 215 miles per hour. This level of performance requires both exceptional mechanical preparation and highly skilled drivers who understand every aspect of their vehicle's behavior.

Pro Stock is one of four professional categories in the National Hot Rod Association (NHRA), alongside Top Fuel, Funny Car, and Pro Stock Motorcycle. The class is known for extremely strict rules and regulations that keep competition close and exciting. Because the rules limit certain modifications, success comes down to precise tuning, driver skill, and attention to detail.

Variations of Pro Stock exist in other countries and sanctioning bodies. For example, Australian Pro Stock uses slightly smaller engines limited to 401 cubic inches, while Mountain Motor Pro Stock allows massive engines up to 825 cubic inches that produce around 1,800 horsepower.