{"product_id":"project-mu-fs4m-4pot-front-bbk-315x30mm-zn6-zc6-zn8-zd8","title":"Project Mu FS4M 4POT Front BBK 315x30mm for 2013+ FRS\/BRZ\/86 2022+ BRZ\/GR86","description":"\u003cp style=\"text-align: left;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0273\/1491\/files\/download_89a23d83-7a50-4507-9890-c1ec4e9d0b4d.png?v=1760034359\" alt=\"Project Mu Banner\" style=\"display: block; margin-left: auto; margin-right: auto; max-width: 100%; height: auto;\"\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eOVERVIEW\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003eStrengthen front stopping capability and improve brake pedal feel with the Project Mu 4POT FS4M Street Forged Front Caliper Kit for 2013+ GR86 \/ BRZ \/ 86 \/ FR-S (ZN6\/ZC6\/ZN8\/ZD8). Designed specifically for street enthusiasts and weekend canyon drivers, the FS4M features a compact forged aluminum body housing 38mm pistons. By pairing this rigid 4-piston caliper with 315mm x 30mm 1-piece round 6-slit rotors, Project Mu achieves high-performance thermal capacity while retaining clearance for most OEM and aftermarket 17-inch wheels. It serves as an accessible entry into forged aluminum brake upgrades without requiring aggressive wheel offsets.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\n\u003c!-- FRONT-TO-FRONT PRODUCT COMPARISON TABLE --\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; text-align: left;\" border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth style=\"padding: 8px;\"\u003eCaliper Feature \/ Spec\u003c\/th\u003e\n\u003cth style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003eFS4M Street 4POT\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth style=\"padding: 8px;\"\u003e\u003cstrong\u003eFS44S Slim 4POT\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth style=\"padding: 8px;\"\u003e\u003cstrong\u003eFS44 Full-Size 4POT (345mm)\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth style=\"padding: 8px;\"\u003e\u003cstrong\u003eFS44 Full-Size 4POT (355mm)\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eAxle Position\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003eFront Axle Specific\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eFront Axle Specific\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eFront Axle Specific\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eFront Axle Specific\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eCaliper Profile \u0026amp; Width\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003eCompact Street Body (275.0mm L x 144.5mm W)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eSlim Body (140.2mm Width - High Spoke Clearance)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eStandard Full Body (156.25mm Width - Heavy Duty)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eStandard Full Body (156.25mm Width - Heavy Duty)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003ePiston Diameter \/ Pad Layout\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003e38mm Pistons x 4 (2-Pads per Caliper)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e38mm Pistons x 4 (4-Pads per Caliper)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e41mm Oversized Pistons x 4 (4-Pads per Caliper)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e41mm Oversized Pistons x 4 (4-Pads per Caliper)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eRotor Specs \u0026amp; Thickness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003e315mm x 30mm (1-Piece Round 6-Slit)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e355mm x 28mm (2-Piece Straight 8-Slit)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e345mm x 32mm Heavy-Duty (2-Piece Straight 8-Slit)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e355mm x 32mm Heavy-Duty (2-Piece Straight 8-Slit)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eTarget Application\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; background-color: #d9ead3;\"\u003e\u003cstrong\u003eStreet Performance \/ Canyon \u0026amp; OEM 17\" Wheel Friendly\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eStreet \u0026amp; Track with Tight Wheel Clearance\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eHeavy-Duty Circuit \/ 17\"+ Wheel Friendly Track Day\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eHeavy-Duty Circuit \/ Maximum Heat Mass (18\"+ Wheels)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eFEATURES\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eCompact Forged Caliper Body:\u003c\/strong\u003e Lightweight forged aluminum alloy structure provides high pedal response and rigidity without excessive weight.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003e38mm 4-Piston Architecture:\u003c\/strong\u003e Sized for street and spirited driving to maintain factory master cylinder hydraulic proportioning.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003e315mm x 30mm Vented 1-Piece Rotors:\u003c\/strong\u003e Cost-effective 1-piece round 6-slit rotors provide enhanced thermal management over stock rotors while retaining 17-inch wheel fitment.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eRound 6-Slit Face Design:\u003c\/strong\u003e Degasses pad friction material and maintains clean pad surfaces for consistent initial bite.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eIntegrated Dust Seal Protection:\u003c\/strong\u003e Features dedicated outer dust seals in front of the main oil seals to guard internal hydraulics against road debris and dust.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eWHAT IS INCLUDED\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e2x Project Mu FS4M Forged 4-Piston Front Calipers (Signature Teal Finish)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e2x Project Mu 315mm x 30mm 1-Piece Front Brake Rotors (Round 6-Slit)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e4x Project Mu Performance Front Brake Pads (Standard NS-C Compound)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e2x CNC Machined Caliper Mounting Brackets \u0026amp; Hardware\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003e2x Stainless Steel Braided Brake Lines with Teflon Inner Core\u003c\/span\u003e\u003c\/li\u003e\n\u003cli role=\"presentation\" dir=\"ltr\"\u003e\u003cspan\u003eComplete Set of Installation Bolts \u0026amp; Hardware\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003ePART NUMBERS\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e FS4M-F103SP\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eSPECIFICATIONS\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003ePosition:\u003c\/strong\u003e Front Axle\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eCaliper Type:\u003c\/strong\u003e Forged Aluminum Compact 4-Piston (FS4M)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003ePiston Diameter:\u003c\/strong\u003e 38mm x 4\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eCaliper Dimensions:\u003c\/strong\u003e Length: 275.0mm | Width: 144.5mm | Height: 71.6mm\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eRotor Dimensions:\u003c\/strong\u003e 315mm Diameter x 30mm Thickness (1-Piece)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eRotor Venting \/ Slits:\u003c\/strong\u003e Vented with Round 6-Slit Pattern\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eStandard Included Compound:\u003c\/strong\u003e Project Mu NS-C (Optional: TYPE PS or D1 spec ZERO)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eFinish:\u003c\/strong\u003e Hard Anodized + Signature Teal Powder Coat\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eFITMENT\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e2022+ Toyota GR86 (ZN8) \u0026amp; Subaru BRZ (ZD8)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e2013-2021 Toyota 86 \/ Scion FR-S (ZN6) \u0026amp; Subaru BRZ (ZC6)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cem\u003e*Fits most OEM and aftermarket 17-inch or larger wheels\u003c\/em\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2 style=\"text-align: center;\" dir=\"ltr\"\u003e\u003cspan\u003eDISCLAIMER\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eBackplate Processing Required:\u003c\/strong\u003e Installation requires trimming or modifying OEM front brake dust shields\/backplates.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eNon-Affiliation \u0026amp; Warranty:\u003c\/strong\u003e Direct parallel import of authentic JDM components. We are an independent retailer, not an authorized Project Mu dealer. Factory warranty applies in Japan only.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003e14-Day Defect Window:\u003c\/strong\u003e 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.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eInstallation:\u003c\/strong\u003e Manuals are in Japanese. Professional installation by a certified technician is required.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Project Mu","offers":[{"title":"Default Title","offer_id":48574713364692,"sku":"FS4M-F103S","price":2895.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0273\/1491\/files\/Project_Mu_FS4M_4POT_Front_BBK_315x30mm_ZN6_ZC6_ZN8_ZD8.jpg?v=1787934308","url":"https:\/\/shop.battlegarage-rs.com\/products\/project-mu-fs4m-4pot-front-bbk-315x30mm-zn6-zc6-zn8-zd8","provider":"Battle Garage Racing Service","version":"1.0","type":"link"}