Project Mu PBR961 B-Force Rear Brake Pads for 2017-2021 Subaru STI 6-Pot Brembo

Vehicle Fitment

• 2017-2021 Subaru WRX STI (with Factory 6-Pot Brembo Front Calipers, 2.5L EJ257 H4 Turbo)
• 2024-2025 Subaru WRX TR/TS (with Factory 6-Pot Brembo Front Calipers)

Fitment Notes

• Designed specifically for STI models equipped with the factory 6-piston Brembo front caliper - not compatible with 4-pot Brembo or standard caliper variants
• Rear brake pads only - front pads sold separately under PBF960
• Suitable for street driving, performance driving, and light track use - not designed for sustained high-temperature circuit sessions
• Low dust and low noise characteristics make these suitable for daily street use

Features

• B-Force compound delivers strong initial bite and reliable stopping power from cold temperatures - effective for both street and light track use
• Improved fade resistance over OEM pads - maintains consistent braking feel under repeated hard applications
• Super graphite metallic material provides a higher friction ceiling than standard organic or ceramic compounds
• Gentle on brake rotors - minimal rotor wear extends disc service life compared to more aggressive compounds
• Economical long-lasting formulation balances performance with pad longevity
• Low dust output and reduced squeal for a clean, quiet daily driving experience
• Compatible with semi-slick tires for track day use
• Made in Japan by Project Mu - over 35 years of motorsport brake engineering expertise

Specifications

• Part Number: PBR961
• Compound: B-Force
• Position: Rear (pair)
• Material: Super Graphite Metallic
• Application: Street Driving / Performance Driving / Light Track Duty
• Applicable Rotor Temperature: 0-500°C
• Friction Coefficient (µ): 0.32-0.45
• Caliper Compatibility: Factory 6-Pot Brembo (STI / WRX TR/TS)
• Origin: Made in Japan
• Warranty: 1 Year

Included Components

• 1x Set of Project Mu B-Force Rear Brake Pads (PBR961)

Product Description

The Project Mu PBR961 B-Force rear brake pads are engineered specifically for the 2017-2021 Subaru WRX STI equipped with the factory 6-piston Brembo front caliper system, as well as the 2024-2025 WRX TR/TS. The B-Force compound is designed to strike a balance between reliable street performance and light-to-moderate track capability - delivering strong initial bite from cold and improved fade resistance compared to OEM pads, without the aggressive heat requirements or high dust output of full race compounds.

The super graphite metallic formulation is gentle on rotors, extending disc life while still providing the friction needed for spirited driving and occasional track days. Low dust and minimal squeal keep the B-Force well-suited for daily use. For front pads on the same 6-pot Brembo application, see PBF960. Backed by Project Mu's 1-year manufacturer warranty.