Wilwood 140-18366 Forged Narrow Superlite 6R Front Big Brake Kit for Mustang II / Roadster Shop RSF-2 Spindle

The Wilwood 140-18366 is a front big brake kit built around the Forged Narrow Superlite 6R (FNSL6R) six-piston caliper, delivering race-proven stopping power with modern engineering and premium aesthetics. Engineered specifically for Roadster Shop SPEC and REVO RS chassis equipped with the RSF-2 forged 6000-series spindle, this kit provides a fully bolt-on upgrade without compromising performance or fitment integrity.

Key Features:

• Forged Narrow Superlite 6R six-piston calipers — forged aluminum construction delivers exceptional clamping force while reducing unsprung weight
• 12.88" vented iron rotor — large-diameter, 48-vane vented design maximizes heat dissipation and braking durability under demanding conditions
• Lightweight two-piece aluminum hat — reduces rotational mass for improved response and a cleaner, show-quality appearance
• Increased piston volume — generates stronger clamping force with reduced pedal effort for confident, consistent braking feel
• BP-10 street performance brake pads — engineered for quick initial response, fade resistance, and extended pad life in street and dual-purpose applications
• Requires 17" or larger wheels for proper clearance
• Multiple caliper finish colors and rotor styles available; track-only upgrades available by custom order

The FNSL6R caliper features stainless steel pistons with a total piston area of 4.04 sq. in. and a pad plate size of 7416, offering outstanding thermal resistance and long-term reliability. This kit is purpose-built for high-performance street and track builds using the Mustang II / RSF-2 spindle platform, making it an ideal choice for custom chassis, pro-touring, and restomod projects that demand serious braking capability.