ZRP Std Intake Valves Black Nitride for Audi VW Volkswagen 2.5L TFSI TT-RS RS3 EA855

Audi / VW 2.5L TFSI (EA855) TT-RS / RS3 / Q2 RS – ZRP Standard Intake Black Nitrided Valves (Set of 10)

ZRP Standard Intake Black Nitrided Valves are designed for high-performance Audi and Volkswagen 2.5L TFSI EA855 engines used in the TT-RS, RS3, and Q2 RS models. Engineered for demanding street and motorsport applications, these valves provide exceptional durability, precise valve control, and long-term reliability under high boost and high-RPM conditions.

Manufactured from one-piece forged high-grade 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 resistance and fatigue strength while reducing friction between the valve stem and guide thanks to the smoother, hardened surface.

Unlike localized chrome coatings, the entire valve — including both the stem and the valve head — receives the black nitrided treatment, ensuring uniform protection and extended service life.

Each valve is precision forged, CNC-machined, polished, and tip hardened to meet strict dimensional tolerances. This guarantees accurate valve seating, stable high-RPM operation, and consistent sealing performance in both naturally aspirated and turbocharged engines.

Technical Features

• Base Material: High-grade stainless steel (EV8 / 21-4N)

• Surface Hardness: Black nitrided layer with hardness up to approx. 800 HV

• Manufacturing Process: Precision forged, CNC-machined, polished, and tip hardened

• Treatment Coverage: Full black nitriding of the entire valve (stem and head)

• Dimensional Accuracy: Tight tolerances for stem concentricity, straightness, and sealing surface finish

Advantages

• Reduced stem-to-guide friction for lower wear and improved high-RPM stability

• Significantly longer service life compared to untreated stainless-steel valves

• Reliable sealing in both naturally aspirated and turbocharged engines

• Suitable for high-performance street builds and demanding motorsport applications

Additional Information

• Set Quantity: 10 valves

• Material: Black Nitride

• Valve Size: 33.85 mm head / 5.98 mm stem / 104.00 mm length

• Application: 2.5L TFSI (EA855) – TT-RS, RS3, Q2 RS

• Engine Codes: CEPA, CEPB, DNWA, CZGB, CTSA, CZGA, DAZA