{"product_id":"gsc-4b11-evo-x-valves-exhaust","title":"GSC 4B11 Evo X Exhaust Valves","description":"GSC Power-Division exhaust valves for the 4B11 Evo X. Exhaust valves are sold as a set of 8 or individually as needed. Choose the standard modified 23-8N stainless material or 2000°F Super Alloy. Available in the standard 29mm size or +1mm oversized. Valve stem diameter is 5.5mm, overall length is 105.85mm.\u003cbr\u003e\u003cbr\u003e\u003cspan style=\"color: #ff2a00;\" data-mce-style=\"color: #ff2a00;\"\u003eVehicle Fitment:\u003c\/span\u003e\u003cbr\u003eMitsubishi 4B11\u003cbr\u003e2008-2015 Evolution X\u003cbr\u003e\u003cbr\u003e\u003cspan style=\"color: #ff2a00;\" data-mce-style=\"color: #ff2a00;\"\u003eGSC Exhaust Valves:\u003c\/span\u003e\n\u003cdiv style=\"overflow-x: auto;\" data-mce-style=\"overflow-x: auto;\"\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003ePart Number:\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eHead Diameter Size:\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eMaterial:\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eQuantity:\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2021-8\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSTD Size (29mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e23-8N\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSet of 8\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2021-01\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSTD Size (29mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e23-8N\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSingle Valve\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2023-8\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e+1mm (30mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e23-8N\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSet of 8\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2023-01\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e+1mm (30mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e23-8N\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSingle Valve\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2025-8\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSTD Size (29mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSuper Alloy\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSet of 8\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2025-01\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSTD Size (29mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSuper Alloy\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSingle Valve\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2027-8\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e+1mm (30mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSuper Alloy\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSet of 8\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eGSC 2027-01\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003e+1mm (30mm)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSuper Alloy\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan style=\"color: #ffffff;\" data-mce-style=\"color: #ffffff;\"\u003eSingle Valve\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cbr\u003e\u003cspan style=\"color: #ff2a00;\" data-mce-style=\"color: #ff2a00;\"\u003eSuper Alloy:\u003c\/span\u003e\u003cbr\u003eGSC Power-Division Super Alloy Exhaust Valves are for those running high horsepower, high EGT set ups that need a valve that will last in 2000°F conditions. The Super Alloy Exhaust valves have chrome polished stems to create a smooth, durable finish for added life and better lubricity, especially when paired with the GSC Manganese bronze valve guides. Strength, heat resistance, and performance are engineered into every valve. Under head dish is maximized for weight savings while swirl polished and back cut heads promote better air flow without sacrificing durability. \u003cbr\u003e\u003cbr\u003e\u003cspan style=\"color: #ff2a00;\" data-mce-style=\"color: #ff2a00;\"\u003eMore Info:\u003c\/span\u003e\u003cbr\u003eUsing advanced 3D design and simulation software, GSC has created a stronger and higher flowing valve head design. GSC flow tests prototype valve heads in the specific applications to ensure the highest flowing valve head available on the market today. With the materials used, GSC offers less valve distortion at the face than any of the tested designs. Less distortion allows for better sealing under extreme conditions and more consistent performance throughout the life of the valve.\u003cbr\u003e\n\u003cul\u003e\n\u003cli\u003eSwirl polished heads for smoother air flow over the valve\u003c\/li\u003e\n\u003cli\u003eBack cut to reduce valve weight for higher RPM, higher boost pressure, and allow for more aggressive cam profiles without increasing valve spring seat pressures\u003c\/li\u003e\n\u003cli\u003eValve stems are micro polished to allow for less oil retention on the stem, which creates less drag on the stem to guide for a smoother motion\u003c\/li\u003e\n\u003cli\u003eIntake valves are a modified 21-4n stainless and exhausts are a modified 23-8n stainless material for high heat capacity while maintaining longevity\u003c\/li\u003e\n\u003cli\u003eValve tips are either hardened or have a stelite wafer tip fused so that the tip is within 5 Rockwell C of the rocker or valve tappet for extended life and less wear\u003c\/li\u003e\n\u003cli\u003eValve tip lengths - GSC takes extra time to adjust tip heights on the applications to require less tipping of the valve, to maintain proper tip height for proper valve train geometry, and to cut down on install times when setting valve lash\u003c\/li\u003e\n\u003cli\u003eGSC has also adjusted the keeper groove to properly balance intake and exhaust spring pressures to reduce the use of valve spring shims and maximize performance from GSC spring and retainer kits\u003c\/li\u003e\n\u003cli\u003eValves will work with an OEM keeper\/lock or, when available, GSC upgraded keeper\/lock. It is not mandatory, but it is suggested, that any valve lock not be reused on performance applications due to material grooving\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cspan style=\"color: #ff2a00;\" data-mce-style=\"color: #ff2a00;\"\u003ePictured:\u003c\/span\u003e\u003cbr\u003ePhotos are for reference.\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/stmtuned.com\/collections\/gsc-power-division-products\" style=\"color: #afafaf;\"\u003e\u003cbr\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003cspan style=\"font-size: .8em;\"\u003e See more GSC Products\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/a\u003e","brand":"GSC","offers":[{"title":"STD 29mm Set of 8 (GSC2021-8)","offer_id":50564619567446,"sku":"GSC-2021-8","price":158.84,"currency_code":"EUR","in_stock":true},{"title":"STD 29mm Single Valve (GSC2021-01)","offer_id":50564619600214,"sku":"GSC-2021-01","price":19.38,"currency_code":"EUR","in_stock":true},{"title":"'+1 30mm Set of 8 (GSC2023-8)","offer_id":50564619632982,"sku":"GSC-2023-8","price":159.94,"currency_code":"EUR","in_stock":true},{"title":"'+1 30mm Single Valve (GSC2023-01)","offer_id":50564619665750,"sku":"GSC-2023-01","price":19.38,"currency_code":"EUR","in_stock":true},{"title":"Super Alloy STD 29mm Set of 8 (GSC2025-8)","offer_id":50564619698518,"sku":"GSC-2025-8","price":246.62,"currency_code":"EUR","in_stock":true},{"title":"Super Alloy STD 29mm Single Valve (GSC2025-01)","offer_id":50564619731286,"sku":"GSC-2025-01","price":30.0,"currency_code":"EUR","in_stock":true},{"title":"Super Alloy +1 30mm Set of 8 (GSC2027-8)","offer_id":50564619764054,"sku":"GSC-2027-8","price":252.11,"currency_code":"EUR","in_stock":true},{"title":"Super Alloy +1 30mm Single Valve (GSC2027-01)","offer_id":50564619796822,"sku":"GSC-2027-01","price":34.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0817\/9531\/8102\/files\/gsc-4b11-evo-x-valves-exhaust-8.jpg?v=1749218521","url":"https:\/\/www.speed-addicts.com\/en\/products\/gsc-4b11-evo-x-valves-exhaust","provider":"Speed Addicts","version":"1.0","type":"link"}