{"product_id":"wilwood-st-fsl4r-caliper-for-1-88-1-75-inch-pistons-with-1-25-inch-rotor","title":"Wilwood ST FSL4R Caliper for 1.88\/1.75 Inch Pistons with 1.25 Inch Rotor","description":"FSL4R\/ST calipers provide the pad wear performance advantages of differential bore pistons with the option for ultimate heat protection using Thermlock® pistons in the ST models. Differential piston bores compensate for leading-edge mechanical loading and temperature variances across the pad face to reduce pad taper wear in sustained high temperature applications. Thermlock® pistons in the ST models block heat transfer from the pads and reduce temperatures in the caliper, fluid, and seals by up to 25% over standard stainless steel pistons. Featuring a wear resistant Type III hard anodize finish, these are the go-to calipers for all types sustained hard braking on dirt and asphalt ovals and a wide range of off-road, rally and road course applications.\n\u003cp\u003eThe Wilwood ST FSL4R caliper is engineered for high-performance braking in demanding applications such as dirt and asphalt ovals, off-road racing, rally, and road courses. Featuring differential bore pistons, this caliper ensures even pad wear and optimized performance during sustained high-temperature braking. The differential piston design compensates for mechanical loading and temperature variations across the pad face, significantly reducing taper wear and enhancing brake longevity. The ST model is equipped with Thermlock® pistons, which effectively block heat transfer from the pads, leading to a temperature reduction of up to 25% in the caliper, fluid, and seals, thereby improving overall brake system reliability and preventing overheating issues during intense braking conditions. The caliper's durable Type III hard anodize finish provides exceptional wear resistance, ensuring long-lasting performance in off-road, rally, and high-stress racing environments. Designed to fit 1.88-inch and 1.75-inch pistons with a 1.25-inch rotor, this caliper offers versatile compatibility for a wide range of vehicles and racing setups. Its compact size and robust construction make it an ideal choice for racers seeking consistent, reliable braking performance under sustained hard braking scenarios. Whether used on dirt tracks or asphalt circuits, the Wilwood ST FSL4R caliper delivers exceptional stopping power, heat management, and wear resistance, making it a top choice for professional and enthusiast racers alike.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\u003cli\u003eDifferential bore pistons for even pad wear and temperature compensation\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eThermlock® pistons for up to 25% reduction in heat transfer\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eType III hard anodize finish for wear resistance and durability\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eDesigned for 1.88-inch and 1.75-inch piston configurations\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eCompatible with 1.25-inch rotors for versatile application\u003c\/li\u003e\u003c\/ul\u003e\u003cstyle\u003etable.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; }\u003c\/style\u003e\n\u003ctable class=\"productattributes\"\u003e\n\u003cthead\u003e\u003ctr\u003e\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbdoy\u003e\n\u003ctr\u003e\u003ctd\u003eAir Freight Prohibited: false\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eNot Carb Approved: false\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eLtl Freight Required: false\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eProp 65: Unknown\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003ePart Type: automotive\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eEpa: N\/A\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eCarb Acknowledgement Required: false\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eRegular Stock: false\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eUnits Per Sku: 1\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbdoy\u003e\n\u003c\/table\u003e\u003cbr\u003e","brand":"Wilwood","offers":[{"title":"Default Title","offer_id":53616714055953,"sku":"120-13264","price":468.61,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/3830\/0689\/files\/c10a57fb392174bfcf5792ab3d2aedfbL.jpg?v=1780436588","url":"https:\/\/shoprenegade.com\/products\/wilwood-st-fsl4r-caliper-for-1-88-1-75-inch-pistons-with-1-25-inch-rotor","provider":"Renegade Speed by Renegade Racing \u0026 Performance","version":"1.0","type":"link"}