Wilwood 120-16845 Forged Narrow Superlite Disc Brake Caliper - 6R/ST FNSL6R/ST

The Wilwood Forged Narrow Superlite 6R/ST (FNSL6R/ST) is the latest evolution of Wilwood's proven Superlite caliper series. Engineered with cutting-edge design technology and Thermlock insulated pistons, this six-piston caliper delivers exceptional stopping power in extreme high-temperature environments — making it an ideal choice for a broad range of competition and high-performance street applications.

Stress-Flow Forged Aluminum Body

Starting at just 4.9 pounds, the FNSL6R/ST body is the result of computer-generated solid modeling and FEA (Finite Element Analysis) stress analysis. Each caliper body is stress-flow forged from premium-grade aluminum alloy billets, a process that re-aligns the metal's internal grain structure to follow the contour of the caliper body. This eliminates the internal stress points and grain interruptions introduced by conventional billet machining — producing the strongest possible aluminum caliper construction.

Key Features:

• Six-Piston Differential Bore Configuration: Provides balanced clamping force for even pad wear during sustained high-heat braking
• Thermlock Insulated Pistons: Wilwood's exclusive multi-part piston design creates a highly efficient thermal barrier, reducing heat transfer from the brake pads to the caliper body, seals, and brake fluid — extending service life and reducing the risk of heat-induced pedal fade
• SRS Bridge Plates: Spring-loaded stainless bridge plates eliminate pad gouging wear on the caliper bridge, prevent pad rattle, and dampen harmonic vibrations that contribute to brake squeal
• Dual Two-Piece Bleed Screws: Located on each end of the caliper with internal fluid crossovers to protect against track debris and environmental damage
• High-Temperature Square-Face Bore Seals: Maximize sealing area and provide controlled, consistent piston retraction upon brake release
• Full Wilwood Pad Compound Compatibility: Supports the complete range of Wilwood brake pad compounds to match specific heat ranges and braking response requirements

The FNSL6R/ST is purpose-built for drivers who demand reliable, fade-resistant braking performance across a wide range of racing and high-performance driving conditions. Its combination of forged construction, advanced thermal management, and precision-engineered components makes it one of the most capable calipers in the Wilwood lineup.