Wilwood Forged Narrow Superlite 4R Big Brake Rear Race Kits

Wilwood Forged Narrow Superlite 4R Big Brake Rear Race Kits are configured for dedicated road racing on all 2001-2006 BMW E46 M3 models. They are the engineered match for the AERO6R/ST front race kits. All emphasis is on improved front to rear balance, high durability, and high efficiency heat management, without adding unnecessary rotating or unsprung weight to the driveline and rear suspension. The FNSL4R/ST calipers used in these kits feature a forged aluminum body with a Type III Mil-Spec, medium gray color, hard anodized finish. Hard anodizing provides superior wear resistance in the piston bores, and high resistance to abrasion and corrosion throughout. Thermlock pistons are used to reduce heat transfer from the pads to increase fade resistance, and extend service life by decreasing temperatures in the caliper body, fluid, and seals. Internal damper springs and controlled retraction, high-temperature piston seals assure consistent pedal height from start to finish. Caliper piston volumes are matched for full compatibility with the OE master cylinder output and ABS controls. The calipers are also fully compatible with manual brake conversions to balance bar pedals using appropriately sized master cylinders. Spec37 alloy GT competition series 12.88 in. diameter directional vane rotors are dynamically mounted to the OE hubs with weight-saving forged aluminum hats. As is with the calipers, the hats are hard anodized for superior wear resistance and extended service life at the load bearing surfaces. Further weight reduction is achieved by accommodating the elimination of the parking brake hardware. Mounting brackets, including all premium-grade fasteners, secure the calipers to the uprights in the stock location—with minor modifications to the dust shield, as illustrated in the photos on page 4 of the assembly instructions. These championship-proven systems are completed with high temperature, high friction, endurance compound race pads selected specifically by application. Stainless steel braided flexlines are included in the kit to complete the installation. Show Less