{"product_id":"valvulas-de-admision-zrp-std-con-acabado-nitrurado-negro-para-audi-vw-volkswagen-3-0l-turbo-rs4-rs5-ea839","title":"ZRP Std intake valves with black nitrided finish for Audi VW Volkswagen 3.0L Turbo RS4 RS5 EA839","description":"\u003cp\u003eZRP standard intake valves with black nitride coating for Audi\/VW 3.0L Turbo RS4\/RS5 (EA839) (Set of 12)\u003c\/p\u003e\n\n\u003cp\u003eZRP standard black nitride-coated intake valves are designed for Audi RS4 and RS5 EA839 biturbo engines. Engineered for high-performance and high-boost applications, these valves offer exceptional durability, dimensional stability, and long-term reliability under demanding thermal and mechanical conditions.\u003c\/p\u003e\n\n\u003cp\u003eManufactured from high-quality, one-piece forged stainless steel (EV8\/21-4N), each valve undergoes a specialized black nitriding process. This advanced surface-hardening treatment diffuses nitrogen into the outer layer of the valve, significantly increasing wear and fatigue resistance while reducing friction between the stem and guide due to the hardened, smoother surface.\u003c\/p\u003e\n\n\u003cp\u003eUnlike localized chrome coatings, the entire valve—both the stem and the head—receives the black nitriding treatment, ensuring uniform surface protection and an extended service life. Each valve is precision-forged, CNC-machined, polished, and tip-hardened to meet strict dimensional tolerances. This ensures precise valve seating, stable operation at high RPM, and consistent sealing in turbocharged EA839 engines.\u003c\/p\u003e\n\n\u003cp\u003eTechnical Specifications\u003c\/p\u003e\n\n\u003cp\u003eBase Material: High-quality stainless steel (EV8 \/ 21-4N)\u003c\/p\u003e\n\n\u003cp\u003eSurface Hardness: Nitrided layer up to approx. 800 HV\u003c\/p\u003e\n\n\u003cp\u003eManufacturing Process: Precision forged, CNC machined, polished, and tip-hardened\u003c\/p\u003e\n\n\u003cp\u003eTreatment: Full black nitriding of valve stem and head\u003c\/p\u003e\n\n\u003cp\u003eDimensional Accuracy: Strict tolerances for concentricity, straightness, and sealing surface finish\u003c\/p\u003e\n\n\u003cp\u003eAdvantages\u003c\/p\u003e\n\n\u003cp\u003eReduced friction between stem and guide for less wear\u003c\/p\u003e\n\n\u003cp\u003eIncreased stability at high RPM\u003c\/p\u003e\n\n\u003cp\u003eLonger service life compared to untreated stainless steel valves\u003c\/p\u003e\n\n\u003cp\u003eReliable sealing in high-performance turbocharged engines\u003c\/p\u003e\n\n\u003cp\u003eSuitable for street, track, and endurance racing applications\u003c\/p\u003e\n\n\u003cp\u003eAdditional Information\u003c\/p\u003e\n\n\u003cp\u003eSet Quantity: 12 valves\u003c\/p\u003e\n\n\u003cp\u003eValve Size: 33.85 mm \/ 5.98 mm \/ 104.00 mm\u003c\/p\u003e\n\n\u003cp\u003eEngine: Audi RS4 \/ RS5 EA839 Twin-Turbo Quattro\u003c\/p\u003e\n\n\u003cp\u003eMaterial: Black nitride\u003c\/p\u003e","brand":"ZRP","offers":[{"title":"Default Title","offer_id":56965453971796,"sku":"VI-AUD-006-12","price":399.3,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1027\/4701\/3460\/files\/VI-AUD-006-12_b9bc938d-a8b5-4b8c-88b7-ce6b8027ea35.jpg?v=1788726847","url":"https:\/\/www.thetunerlab.com\/en\/products\/valvulas-de-admision-zrp-std-con-acabado-nitrurado-negro-para-audi-vw-volkswagen-3-0l-turbo-rs4-rs5-ea839","provider":"Thetunerlab","version":"1.0","type":"link"}