Wilwood 120-17724 Aero4 Forged Four-Piston Radial Mount Disc Brake Caliper

The Wilwood Aero4 (120-17724) is a stress-flow forged, four-piston radial mount disc brake caliper engineered for heavy-duty street and track braking performance. Built on race-proven technology, this caliper delivers the stopping force and structural integrity demanded by high-performance and competition applications.

Key Features:

• Stress-flow forged aluminum alloy body — the forging process realigns the metal's internal grain structure to follow the contour of the caliper, eliminating the stress interruptions caused by machining a straight billet block
• Four-piston design with multiple piston volume options for precise brake bias tuning
• Radial mounting for broad adaptability across a wide range of suspension and bracket configurations
• Wide rotor diameter compatibility — supports rotors from 12.88" to 15.00" in diameter, making this caliper suitable for a variety of heavy-weight braking setups
• Internal fluid crossover ports — redesigned from earlier W4A/W6A series calipers, eliminating external crossover tubes and the bulky center bridge assembly for a cleaner, lighter package
• Superior fatigue resistance — the stress-flow forging method produces a caliper with enhanced clamping efficiency and greater resistance to distortion, stress, and fatigue under repeated high-load braking events

The Aero4 represents the latest evolution in Wilwood's W4A/W6A caliper lineage, combining the durability of premium aluminum alloy construction with race-developed engineering. It is an ideal choice for performance street builds, road racing, oval track, and other demanding motorsport applications where consistent, high-clamping braking force is required.