Muscle car racing is a type of competition in which drivers race on a straight course in highly modified cars known as muscle cars. The cars used in muscle car racing are designed with power in mind: the design focuses on forward propulsion rather than on steering ability and agility, and the engines are usually quite large and made for high torque and horsepower situations. Original muscle cars meant for muscle car racing featured large V8 engines mounted inside midsize cars that were lighter than the cars the V8 was designed for. The lighter weight allowed for higher speeds during racing.
As the trend of customizing smaller cars with larger engines continued, some manufacturers began designing cars off the assembly line that met the needs of muscle car racing. The chassis and steering systems were quite simple, since steering was not of high importance to muscle car racing, and the bodies of such cars were made lighter but still fairly large. Racers often customized these cars off the assembly line anyway to improve weight savings, power, and speed off the starting line.
Some muscle cars began to feature oversized rear tires that were wider than conventional tires; this provided more traction, which improved speed. Front tires were narrower to aid in steering and to cut down on drag. This combination of front and rear tires mirrored the style of hot rods, which were also designed for forward speed. As time passed, other innovations helped racers improve engine efficiency and speed; body styles changed to reduce aerodynamic drag, and engines began to feature air intakes, superchargers, and other features that could add power quickly.
Muscle car racing declined in popularity as gasoline prices rose, safety advocates attacked the practice as reckless, and car manufacturers shifted their focus from power to fuel efficiency. This decline continued for years or even decades, until a resurgent interest in muscle car restoration led to sanctioned racing events and car shows. Many muscle car owners restore classic muscle cars for show rather than racing, however, and while the vehicles are still designed for power, these restored models are often modified for in-town driving and focus primarily on aesthetics rather than performance.
Variations on muscle car racing became popular throughout the course of muscle car history. Small pickup trucks were modified for muscle car racing, and they featured much of the same modifications and styles as regular muscle cars. Since the trucks tend to be light in the rear due to the empty truck bed, however, new modifications needed to be developed to aid in traction and speed off the line.
