Wilwood 120-16461 XRZ4R Radial Mount Caliper Left 4 Pistons

XRZ4R Radial Mount

Wilwood’s next-generation XRZero race calipers combine decades of race experience, computer finite element analysis (FEA), and state-of-the-art machining into a race caliper that is lighter and stiffer, with zero drag. The unique shape of the high surface area body creates a caliper with superior brake fluid cooling and allows more airflow through the rotor. Optimized profile high-temperature seals provide better piston retraction resulting in less drag. The unique center X-bridge strengthens the caliper body without adding mass or obstructing airflow to the brake rotor or pads. Computer FEA design and precision CNC machining of the stress-flow forged aluminum body results in a caliper weighing just 4.66 pounds - 1/2 pound less than a comparable sized Wilwood Superlite caliper.

The innovative complex shape of the body removes unnecessary bulk, improves brake and fluid cooling, and actually decreases deflection. Four Thermlock® thermal barrier pistons reduce heat transfer to the brake fluid, and the staggered bore size front calipers provide more even engagement with improved pad wear. Hard-anodized inside the piston bores and on the surface with Type III aluminum-oxide ceramic finish for durability and equipped with single-point bleed technology and low-profile bleed screws for easy serviceability. No-bind pad retaining pins (spare included) hold your choice of multiple 0.80” thick Wilwood race compound brake pads for extended service life.