Z51 Performance Package. The Z51 Performance Package brings Corvette Coupe performance very close to the same level as the widely admired Z06. The Z51 offers more aggressive dampers and springs, larger stabilizer bars, and larger, cross-drilled brake rotors for optimum track performance capability while still providing a well-controlled and comfortable ride. Extensive racetrack testing reveals that a C6 equipped with the Z51 suspension almost equals the lap time of a C5 Z06 - marking a major advance in the overall performance of a Corvette Coupe by nearly approximating the extreme performance capabilities of the vaunted Z06 at a remarkable value.