Rotor Aluminum Sprint 42 Spline

The Wilwood Rotor Aluminum Sprint 42 Spline is a high-performance brake rotor engineered for sprint car racing and extreme motorsport applications where thermal management and rotational dynamics are critical. This drilled aluminum rotor combines lightweight construction with precision engineering to deliver consistent braking performance under sustained high-heat conditions typical of competitive racing environments.

Featuring a 10.200-inch outer diameter and 0.31-inch thickness, this rotor is optimized for rapid heat dissipation through its drilled design, which reduces thermal fade during multiple high-intensity stops. The 42-spline axle mount provides secure, indexable installation with virtually no runout, critical for maintaining brake feel and preventing vibration transfer to the driver. The black anodized aluminum construction delivers the weight savings essential in sprint car platforms while resisting corrosion from moisture and brake fluid exposure. At 2.4 pounds per rotor, the lightweight profile contributes directly to reduced unsprung mass, improving suspension response and acceleration.

Sprint car operators and racing teams standardized on Wilwood components because the brand's rotor geometry and material selection handle the extreme duty cycles of oval track and dirt racing. The drilled design is particularly valuable in dusty or wet conditions where brake dust removal and water shedding prevent pad glazing. Replacement or upgrade installations benefit from the rotor's direct fitment to 42-spline axles, eliminating adapter requirements and maintaining original geometry. This rotor is sold individually, so brake system configurations requiring dual front rotors or matched pairs must order accordingly.