In addition to the necessary brake and wheel changes mentioned previously, the GT2 Corvette racer is based on a ZR1 so this also marks the shift to a space frame made of hydroformed aluminum versus the outgoing steel structure. To attach the steel-tube roll cage mandated by the rules, Pratt & Miller engineers created special anchors that allow a steel spigot to be bolted and glued to aluminum sockets. The resulting corrosion- and stress-resistant joint is used as a welding point for the cage at eight well spaced locations.
In addition to the aluminum space frame, several other production ZR1 components make the leap to the race car with appropriate alterations. That list includes the entire windshield frame including A-pillars and the windshield itself; the steering system including the rack-and-pinion gear, adjustable electric power assist, and a tilt steering wheel; certain brake cooling details; and the behind-the-driver location for the fuel tanks.
GT2 rules also require a close allegiance to the production bodywork (though all panels are made of carbon fiber moldings instead of the production mix of carbon fiber and fiberglass). There are seven permissible deviations: front air inlets in the fascia, front fenders with flares for wider racing tires, a cooling-air exit duct in the hood, blended rocker panels, rear fenders with flares, NACA ducts in the rear deck air to admit transaxle and brake cooling air, and a rear-mounted wing. Compared to the GT1 wing design, the cord (longitudinal dimension) is reduced by 25-percent -- from 15.7 inches to 11.8 inches.
Another notable change is to the minimum weight allowed by the rules. The Corvette GT2Rs must weigh 2745 pounds with all fluids except fuel versus the GT1's 2580 pounds. Up to 77 pounds of ballast is permitted to help lower the center of gravity and to adjust the front-rear weight distribution.
External body dimensions are for the most part unchanged. The 18-inch Michelin racing tires mounted to 12.5-inch wide front and 13.0-inch wide rear wheels are also the same as what was used in GT1. The telemetry system linking the race car's electronic systems to the pits is no longer permitted. Aerodynamic changes yielding less down force include a notably smaller front splitter and a rear diffuser that's both shorter in length and lacking the longitudinal strakes and side fences. The Xtrac transaxle, which offers rapid clutchless sequential shifts and six forward speeds, is one of the rare parts transferred from GT1 to GT2.