Ksport BKBM321-435SO DualComp Rear 4-Piston Big Brake Kit with 13 in. Slotted Rotors

The Ksport BKBM321-435SO DualComp Big Brake Kit is a complete, bolt-on rear brake upgrade engineered for drivers who demand independent foot brake and handbrake performance from a single caliper assembly. Designed with drifting and rally racing in mind, this kit is Formula Drift legal and compatible with 17-inch wheels and above.

DualComp Dual-Function Caliper System:

• Single 4-piston caliper with 2 pistons dedicated to the foot brake and 2 pistons dedicated to the handbrake
• Each circuit operates fully independently on its own hydraulic system for precise, simultaneous control
• Includes a polished titanium handbrake cylinder and lever for improved feel and driver feedback

Two-Piece Floating Rotor Design:

• 330mm (13 in.) slotted rotor with 32mm rotor width
• Lightweight two-piece construction — rotors commonly weigh up to 50% less than OEM rotors of equivalent size
• 6061-T6 aircraft-grade aluminum center bell reduces rotational mass for sharper brake response
• Outer rotor ring expands and contracts independently from the center, significantly reducing warp risk under sustained heat
• Aluminum center sections act as heat sinks, dissipating thermal energy away from the hub assembly faster

Hardware and Construction:

• CNC machined carbon steel caliper brackets for direct bolt-on fitment to OEM caliper bracket locations
• D.O.T. compliant stainless steel braided brake lines included as standard
• SC1 street brake pads included
• No vehicle modifications required in most applications

What's Included:

• 4-Piston DualComp Rear Calipers
• Two-Piece Floating Slotted Brake Disc (330mm / 13 in.)
• SC1 Street Brake Pads
• Polished Titanium Handbrake Assembly
• CNC Carbon Steel Caliper Brackets
• Stainless Steel Braided Brake Lines
• All required mounting hardware

All Ksport Big Brake Kits are backed by a 12-month manufacturer's warranty covering defects. Kits are built to order.