The 2C was developed as an evolution of the earlier fiberglass-chassised Chaparral 2 variants that Hall and Sharp had raced since 1963. Where the 2A and 2B had used fiberglass structures, the 2C adopted a Chevrolet-designed aluminium chassis that made the car more compact in every dimension than its predecessors. The change in construction material came at a cost: without the natural vibration-damping properties of fiberglass, the aluminium chassis transmitted road and mechanical vibrations directly to the driver far more aggressively. Hap Sharp gave the car the nickname EBJ, short for eyeball jiggler, in acknowledgment of this characteristic.
The defining feature of the 2C was its adjustable rear wing, operable by the driver via a dedicated third pedal inside the cockpit. The mechanism drew conceptual parallels with the air brake system used on the Mercedes-Benz 300 SLR in the 1955 Le Mans race, but applied the principle to aerodynamic downforce management rather than pure braking. When the pedal was depressed, the wing lay flat to reduce drag on straights and allow higher top speeds. When released, the wing returned to a negative incidence angle, generating downforce and improving stability and braking performance in corners.
This system was made viable by Chaparral's semi-automatic transmission, which had been developed in collaboration with engineers at General Motors. The clutchless transmission freed the driver's left foot from operating a conventional clutch pedal, making a third pedal position available for aerodynamic control. The 2C therefore represented the convergence of two separate technical innovations that Hall and his collaborators had been pursuing across the 2-series development programme.
The 2C was introduced late in the 1965 season for non-championship events, limiting its competitive record compared to the earlier 2A and 2B variants. Its performance in those outings was considered highly successful, validating the adjustable wing concept and informing the design direction Chaparral would take with subsequent models. The 2C's aerodynamic and chassis lessons fed directly into the 2E, which carried the wing concept further with a high-mounted full wing for the 1966 Can-Am season, and into the 2D closed-cockpit variant developed for endurance racing.
The Chaparral 2C established the precedent for active aerodynamics in competition cars. Its driver-adjustable wing was an idea that would reappear throughout racing history, most notably in the drag reduction system introduced to Formula One in the 2011 season, which also allows drivers to open a rear wing element on designated sections of track to reduce drag and assist overtaking. The 2C's combination of aluminium chassis construction, active aerodynamics, and semi-automatic transmission placed it at the forefront of technical development in American sports car racing in the mid-1960s.