Jim Hall and Hap Sharp founded Chaparral Cars in 1962 after acquiring the Chaparral name from original builders Dick Troutman and Tom Barnes, who agreed to allow Hall and Sharp to continue using it for their own constructions. All subsequent Hall and Sharp cars were designated as variants of the Chaparral 2, running from the 2A through to the 2J in sports car and Can-Am form, with the 2K later produced for IndyCar racing. Hall brought a formal engineering education from the California Institute of Technology and applied a methodical, data-driven approach to car development. His access to Firestone's tyre testing programme and the informal collaboration with engineers from General Motors — who provided technical support, transmissions, and access to their research — gave Chaparral capabilities that few privateer teams could match. Hall operated Rattlesnake Raceway, a private test track adjacent to his race shop in Texas, which allowed rapid iterative development far from public scrutiny.
The original Chaparral 2, raced from late 1963 onward, used a distinctive fiberglass chassis at a time when aluminium monocoques and spaceframes were conventional choices. The lightweight and vibration-damping properties of fiberglass gave the car a particular character. Hall and General Motors developed a clutchless semi-automatic transmission that freed the driver's left foot for other tasks — a feature that became integral to later variants' aerodynamic control systems.
Aerodynamic experimentation progressed through successive variants. The 2A used a Kamm-tail profile and quickly accumulated small front-end appendages to counteract lift at speed. The 2B evolved the bodywork further through 1965. The 2C introduced the most significant aerodynamic innovation of the early series: an adjustable rear wing operated by a third pedal in the cockpit. Similar in concept to the air brake on the Mercedes-Benz 300 SLR, the 2C's wing could lie flat on straights to reduce drag and tip up during braking for additional stability. It was the first racing car to feature driver-controlled active aerodynamics. The 2C used a Chevrolet-designed aluminium chassis rather than fiberglass, and was a more compact car. Its aluminium construction reduced the natural damping of the fiberglass structure, leading Hap Sharp to nickname it the EBJ — eyeball jiggler.
The Chaparral 2 competed primarily in the United States Road Racing Championship, the West Coast Pro Series, and from 1966 onward in the Can-Am series. Its most significant early result came in 1965 when it won the 12 Hours of Sebring in difficult wet conditions, a result that established the car's reputation for competitive pace in endurance events. In 1966 and 1967 the 2-series remained among the leading contenders in Can-Am competition.
The series produced several distinct variants for different racing categories: the 2D and 2F were closed-cockpit prototypes for the FIA World Sportscar Championship, while the 2E and later 2G were open Can-Am cars. The 2H pursued a low-drag philosophy for the 1968 Can-Am season. The 2J of 1970 introduced ground effect via twin fans that evacuated air from beneath the car, creating suction downforce through flexible Lexan skirts, but was outlawed after one season. Hall himself was severely injured in a crash at the 1968 Can-Am season finale at the Stardust Grand Prix, effectively ending his driving career, though he continued building and entering cars.
Jim Hall's work with the Chaparral 2 series changed the direction of racing car design. The use of high-mounted rear wings on the 2E and 2F inspired Formula One teams to adopt aerodynamic downforce devices from 1968 onward. The 2J's fan-generated ground effect anticipated the skirt-equipped Formula One cars of the late 1970s. Hall's systematic approach — using data acquisition equipment developed with GM researchers, private testing facilities, and formal engineering analysis — prefigured the modern technical approach to racing car development. A permanent collection of surviving Chaparral cars is displayed at the Permian Basin Petroleum Museum in Midland, Texas.