Project Mu FS44R Forged 4-Piston Rear Brake Kit (345mm 2-Piece Rotors) - 2022+ Toyota GR86 (ZN8) / Subaru BRZ (ZD8) / 2013-2021 Toyota 86 (ZN6)
Regular price
$3,795.00
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OVERVIEW
Maximize rear axle thermal capacity and perfect your overall brake bias with the Project Mu 4POT FS44R Forged Rear Caliper Kit for the 2022+ Toyota GR86, Subaru BRZ, and 2013-2021 Toyota 86. Specifically engineered to balance high-output front big brake kits, the FS44R features a forged aluminum 4-piston caliper utilizing a 4-piston x 4-pad system. By equipping each piston with its own dedicated brake pad, the system ensures uniform pad wear, eliminates tapering under severe track conditions, and delivers immediate, predictable pedal response. Paired with massive 345mm x 32mm 2-piece straight 8-slit floating rotors, this kit provides exceptional fade resistance for high-horsepower circuit applications while retaining factory in-drum parking brake functionality.
| Caliper Feature / Spec | SCR-PRO Rear Rotor Upgrade (OEM Caliper) | FS2A Rear 2POT Kit (Kit FS2A-F204R) | FS44R Rear 4POT Kit (Kit FS44R-F204) | FS44R Large Rear 4POT (Kit FS44R-F204B) |
|---|---|---|---|---|
| Axle Position | Rear Axle Specific | Rear Axle Specific | Rear Axle Specific | Rear Axle Specific |
| Caliper Type / Architecture | Factory Single-Piston Rear Caliper | Compact Rear 2POT Forged Body | Balanced Rear 4POT Forged Body | Large Rear 4POT Forged Body |
| Piston / Pad Architecture | 1-Piston x 1-Pad per side (OEM) | 2-Pistons x 2-Pads (Standard) | 4-Pistons x 4-Pads (1 Pad / Piston) | 4-Pistons x 4-Pads (1 Pad / Piston) |
| Rotor Spec / Design | 290mm x 18mm (2-Piece Direct Replacement) | 316mm x 20mm (2-Piece Straight 8-Slit) | 345mm x 32mm (2-Piece Straight 8-Slit) | 355mm x 32mm (2-Piece Straight 8-Slit) |
| Target Application | OEM Replacement / Street Performance | Street & Light Track Rear Upgrade | Heavy-Duty Trackday & Circuit Rear Upgrade | Maximum Thermal Capacity Circuit Setup |
FEATURES
- Dedicated Rear 4-Piston Architecture: Specifically valved with 38mm pistons to optimize front-to-rear brake balance under heavy deceleration.
- 4-Piston x 4-Pad System: Assigns an individual brake pad to each piston to equalize thermal load, prevent pad tapering, and increase initial bite control.
- Massive 345mm x 32mm 2-Piece Rotors: Oversized 32mm thick floating rotors provide exceptional heat capacity and prevent thermal bleed to rear hub bearings.
- Retains In-Drum Parking Brake: Features a custom steel mounting bracket and in-drum rotor hat mechanism to maintain OEM parking brake function when stationary.
- Straight 8-Slit Vents: 8-slit pattern deglazes friction material and vents out boundary gases during prolonged track sessions.
- Forged Aluminum Construction: High-rigidity forged aluminum alloy caliper body minimizes flex under extreme hydraulic pressure.
WHAT IS INCLUDED
- 2x Project Mu FS44R Forged 4-Piston Rear Calipers (Signature Teal Finish)
- 2x Project Mu 345mm x 32mm 2-Piece Rear Brake Rotors (Straight 8-Slit with In-Drum Mechanism)
- 8x Project Mu Performance Rear Brake Pads (4 Pads per Caliper - Standard NS-C Compound)
- 2x High-Rigidity Steel Caliper Mounting Brackets & Hardware
- 2x Stainless Steel Braided Brake Lines with Teflon Inner Core
- Pad Support Springs & Installation Hardware
PART NUMBERS
- Manufacturer Part Number: FS44R-F204
SPECIFICATIONS
- Position: Rear Axle
- Caliper Type: Forged Aluminum 4-Piston Rear (FS44R)
- Piston Diameter: 38mm x 4
- Caliper Dimensions: Length: 282.8mm | Width: 156.25mm | Height: 72.3mm
- Rotor Dimensions: 345mm Diameter x 32mm Thickness (2-Piece Floating)
- Rotor Venting / Slits: Vented with Straight 8-Slit Pattern
- Standard Included Compound: Project Mu NS-C (Optional: TYPE PS or D1 spec ZERO)
FITMENT
- 2022+ Toyota GR86 (ZN8) - Requires 18-inch wheels or larger
- 2022+ Subaru BRZ (ZD8) - Requires 18-inch wheels or larger
- 2013-2021 Toyota 86 / Scion FR-S (ZN6) - Requires 18-inch wheels or larger
- 2013-2021 Subaru BRZ (ZC6) - Requires 18-inch wheels or larger
DISCLAIMER
- Parking Brake Usage: When installing this system, the OEM in-drum handbrake can only be used as a parking brake while stationary. It cannot be used to lock up or initiate slides while driving.
- Backplate Processing Required: Installation requires trimming or modifying OEM rear brake dust shields/backplates.
- Non-Affiliation & Warranty: Direct parallel import of authentic JDM components. We are an independent retailer, not an authorized Project Mu dealer. Factory warranty applies in Japan only.
- 14-Day Defect Window: Customers must inspect all parts upon arrival. Defect, damage, or missing part claims must be reported within 14 days of delivery and prior to installation. Installed items are non-returnable.
- Installation: Manuals are in Japanese. Professional installation by a certified technician is required.