Supertech Toyota Supra 1JZGE/1JZGTE Inconel Exhaust Valve - +1mm Oversize - Set of 12 - TEVI-1009-12

Stainless Steel Black Nitride Exhaust Valves

Supertech's Black Nitride exhaust valves are manufactured from premium EV8 (21-4N) stainless steel and finished with a proprietary Black Nitride surface treatment. This coating provides superior hardness, reduced friction, and enhanced corrosion resistance compared to standard stainless valves.

Each valve is precision-machined to OEM tolerances and undergoes rigorous quality control including dimensional inspection, hardness testing, and surface finish verification. The result is a valve that delivers consistent, reliable performance in both street and competition applications.

Key Features

• EV8 / 21-4N stainless steel base material for high-temperature strength
• Black Nitride surface treatment for reduced friction and wear resistance
• Precision-ground stem and face for optimal sealing
• Swirl-polished underhead for improved exhaust flow
• Compatible with standard valve guides and seats
• Available in standard and oversize diameters

Applications

Ideal for naturally aspirated, turbocharged, and supercharged engines where exhaust valve durability is critical. The Black Nitride coating excels in high-EGT environments and is particularly well-suited for engines running lean air-fuel ratios or aggressive ignition timing.