Project Mu Forged Sports Caliper FS4M 4POT Front Big Brake Kit (315x30mm 1-Piece Rotors) for 2013+ FRS/BRZ/86 2022+ BRZ/GR86
Regular price
$2,850.00
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OVERVIEW
The Project Mu FS4M Forged Street 4POT Front Caliper Kit delivers high-performance multi-piston braking capabilities at an accessible price point for the Toyota 86 and GR86 platform. Designed specifically for street performance and daily-driven track builds, the compact forged aluminum body provides excellent structural rigidity, reduced unsprung weight, and superior heat dissipation over stock single-piston floating calipers. Paired with 315x30mm 1-piece slotted rotors, this kit provides exceptional pedal response and thermal stability while maximizing clearance for popular 17-inch wheel setups.
| Caliper Feature / Spec | FS4M Street (FS4M-F103SP) | FS44 Slim (FS44S-F103) | FS44 Full (FS44-F103A) | FS6 6POT (FS6-F103A) |
|---|---|---|---|---|
| Primary Purpose | Street / Light Track | Fast Road / Track Day | Full Track / Time Attack | Competition / Endurance |
| Caliper Construction | Forged Aluminum (Compact) | Forged Aluminum (Slim) | Forged Aluminum (Full-Size) | Forged Aluminum (6POT) |
| Piston Configuration | 4 Pistons (38mm) | 4 Pistons (38mm) | 4 Pistons (41mm / 38mm) | 6 Pistons (38mm / 32mm / 28mm) |
| Pads per Caliper | 2 Pads | 4 Pads | 4 Pads | 2 Pads |
| Rotor Size & Style | 315x30mm 1-Piece Slotted | 332x28mm 2-Piece Floating | 345x32mm 2-Piece Floating | 345x32mm 2-Piece Floating |
| Wheel Clearance | High (Fits many 17" wheels) | Moderate (17"-18" wheels) | 18" Wheels required | 18" Wheels required |
FEATURES
- Forged Aluminum Alloy Construction: Offers maximum structural rigidity and low deflection under aggressive thermal and physical loads while reducing unsprung mass.
- Street-Focused Compact Profile: Engineered specifically to maintain tight clearances for 17-inch wheels without requiring extreme offset wheels or spacers.
- Weather & Dust Seal Protection: Features internal fluid seals paired with dedicated outer wiper dust seals to protect pistons from road debris and moisture.
- 1-Piece High-Carbon Slotted Rotors: Includes durable 315x30mm 1-piece rotors with 6 curved slits to continuously sweep pad faces clean and expel gases.
- Includes NS-C Brake Pads: Comes standard with Project Mu NS-C street pads, providing low dust, quiet operation, and high initial bite for daily driving.
WHAT IS INCLUDED
- (2) Project Mu FS4M 4-Piston Forged Front Calipers (Teal Finish)
- (2) Project Mu 315x30mm 1-Piece Slotted Front Brake Rotors
- (1) Front Set of Project Mu NS-C Street Brake Pads
- (2) Heavy-Duty Steel Caliper Mounting Brackets
- (2) Project Mu Teflon-Lined Stainless Steel Braided Brake Lines
- Complete Installation Hardware Set & Mounting Bolts
PART NUMBERS
- Manufacturer Part Number: FS4M-F103SP
SPECIFICATIONS
- Position: Front
- Caliper Type: FS4M Forged Street 4-Piston Caliper
- Piston Diameter: 38mm
- Caliper Dimensions: 275.0mm (L) x 144.5mm (W) x 71.6mm (H)
- Rotor Dimensions: 315mm Diameter x 30mm Thickness (1-Piece Construction)
- Rotor Venting / Slits: Curved 6-Slit Pattern
- Standard Included Compound: Project Mu NS-C (Optional TYPE PS / D1 Spec available upon request)
- Finish: Hard Alumite + Project Mu Teal Powder Coat
FITMENT
- 2013–2020 Toyota 86 / Scion FR-S / Subaru BRZ (ZN6 / ZC6 Chassis)
- 2022+ Toyota GR86 / Subaru BRZ (ZN8 / ZD8 Chassis)
- Note: Engineered for 17-inch wheel compatibility; always verify clearance using a Project Mu wheel fitment template before installation.
DISCLAIMER
- Backplate Processing Required: Installation requires trimming or modifying OEM 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.