Mazda RX7 FD3S Rear BBK (Standard Performance)

Rear Standard Performance Big Brake Kit – Mazda RX-7 FD3S

The Rear Standard Performance Big Brake Kit is a complete, validated rear brake upgrade engineered specifically for the 1992–2002 Mazda RX-7 FD3S chassis.

This system combines a motorsport-grade Wilwood Forged Superlite Internal 4-piston caliper with a 12.72" (323mm) rear rotor configuration and precision CNC-machined 7075-T6 rear caliper adapters.

⚠ This setup deletes the factory rear parking brake.
⚠ For off-road / motorsport use only.

What’s Included

• Wilwood Forged Superlite Internal 4-Piston Calipers
• 12.72" (323mm) Rear Rotors (DBA 4000 Series – T2 or XS)
• Wilwood 7420 Brake Pads (compound selectable)
• CNC-Machined 7075-T6 Rear Caliper Adapter Brackets (Left & Right)
• Zinc-plated mounting hardware
• Caliper brake line fittings (1/8-27 NPT to -3AN)
• Rear -3AN PTFE braided brake lines

OSC Rear Caliper Adapter System

• Machined from 7075-T6 aerospace-grade aluminum
• CNC precision cut for dimensional accuracy
• Bead blasted surface preparation
• Gloss Black Type II anodized finish
• Engineered specifically for FD3S rear upright geometry

7075-T6 was selected for its superior strength-to-weight ratio and structural rigidity under high braking loads.

Caliper Specifications

• Wilwood Forged Superlite Internal
• 4 Piston – 1.38" bore (3.00 in² total piston area)
• 3.50" Lug Mount
• Rotor Width: 0.75" – 0.84" (Designed for 0.81")
• Pad Shape: Wilwood 7420
• Inlet Thread: 1/8-27 NPT

Brake Pad Specifications & Compound Selection

This kit utilizes the Wilwood 7420 pad shape, providing broad compound flexibility depending on vehicle use and driving conditions.

Pad Shape: Wilwood 7420

Available Compounds:

• BP-Q (Ceramic Street) – Low dust, low noise, daily driving focused
• BP-10 (Street Performance) – Improved bite over OEM, ideal for spirited street use
• BP-20 (Street + Track) – Higher temperature capability for aggressive driving
• BP-28 (Track Focused) – Increased friction and heat capacity for repeated hard braking
• BP-30 / BP-35 / BP-40 / BP-45 (Racing Compounds) – Designed for motorsport applications; elevated operating temperature ranges

Compound selection should match intended vehicle use. Higher friction racing compounds may generate increased noise, dust, and rotor wear during street driving.

Rotor Specifications

• Diameter: 12.72" (323mm)
• Rotor Width: 0.81"
• Base Application: 2004–2011 Mazda RX-8 (Sport Suspension)

Validated Rotor Options:

• DBA42550S – T2 Slot
• DBA42550XS – XS Bi-Symmetrical Slot

Additional Confirmed Compatible Rotors

The following rotors have also been physically confirmed for compatibility with the OSC Rear Adapter geometry. These are not offered directly due to manufacturer availability changes but are listed for reference:

• StopTech 126.45071SL (Slotted – Left)
• StopTech 126.45071SR (Slotted – Right)
• StopTech 127.45071L (Slotted & Drilled – Left)
• StopTech 127.45071R (Slotted & Drilled – Right)
• Centric 120.45071 (Plain)

If deviating from the validated DBA rotor options, confirm all dimensions prior to installation.

Parking Brake

This configuration removes the OEM rear parking brake system.

No mechanical or electronic parking brake solution is included.

An electronic parking brake solution is currently under development.

Wheel Clearance

• Verify wheel barrel diameter clearance
• Verify spoke clearance
• Perform test fitment before final assembly

Installation Notes

• Adapter to Spindle (M10x1.25, 10.9): 45 ft-lb
• Caliper to Adapter (7/16-14, Grade 8): 55–60 ft-lb
• Use Loctite 271 (Red)
• Hand tools only – no impact tools
• Fully bleed system before operation

Professional installation strongly recommended.

Summary

The Rear Standard Performance Kit provides a complete, validated 12.72" rear big brake configuration for the Mazda RX-7 FD3S using forged Wilwood calipers, 7075-T6 CNC adapters, and high-performance 323mm rotors.

Deviation from the listed components may affect fitment and performance.