Manley Performance Extreme Duty Stainless Steel Valves 2002-2005 WRX / 2004-2014 STI Crafted

Description

Manley Performance Extreme Duty Stainless Steel Valves 2002-2005 WRX / 2004-2014 STI | High-Performance Engine Rebuild Parts | Valves

Overview

Designed specifically for Subaru enthusiasts looking to maximize their engine’s potential, the Manley Performance Extreme Duty Stainless Steel Valves are a premium upgrade for 2002-2005 WRX and 2004-2014 STI models. These high-performance valves are essential components for those building or rebuilding engines, especially in forced induction setups where durability and airflow are critical. Crafted from top-tier stainless steel, they improve engine breathing, enabling more power and enhanced reliability under demanding conditions.

Manley’s engineering philosophy centers on combining strength with precision. These valves feature a fully machined, swirl-polished surface, chrome stems, and hardened tips, ensuring longevity even in high-heat, high-stress environments. The intake valves utilize NK-842 stainless steel, while the exhaust valves are made from XH-426 stainless steel, both selected for their superior heat resistance and durability. The Pro Flo underhead design optimizes airflow, promoting better combustion efficiency and power delivery. Whether you’re upgrading your turbocharged build or performing a comprehensive engine rebuild, these valves provide the strength and flow characteristics needed for peak performance. Subaru owners who demand reliability and performance from their engines will find these valves to be a vital component in their build.

Features & Specifications

This Manley Performance Extreme Duty Stainless Steel Valves set is engineered for Subaru WRX and STI platforms and features high-grade stainless steel construction for durability and performance.

• Brand: Manley Performance
• Product: Extreme Duty Stainless Steel Valves 2002-2005 WRX / 2004-2014 STI
• Part Number: Not specified
• Fitment: Subaru WRX (2002-2005), Subaru STI (2004-2014)
• Material: NK-842 stainless steel (intake), XH-426 stainless steel (exhaust)
• Finish: Chrome stems, swirl polished surface
• Construction: Fully machined, CNC precision
• Origin: Made in the USA

• Power Gains: Designed to support aggressive builds and tuning, enabling increased airflow and power potential
• Tuning Required: Recommended for optimal performance, especially in boosted applications
• Valve Diameter: 32mm head diameter

Key Benefits

• Enhanced Performance: Improves airflow and combustion efficiency, unlocking more horsepower and torque for your Subaru engine.
• Durability & Heat Resistance: Crafted from premium stainless steel with hardened tips, these valves withstand extreme heat and stress, ideal for turbocharged setups.
• Reliable Rebuilds: Perfect for engine rebuild projects, ensuring long-lasting valve operation under aggressive driving conditions.
• Precision Engineering: Fully machined and swirl polished for optimal airflow and consistent performance.
• Community-Driven Quality: As a Subaru-focused brand, Manley provides parts designed specifically for your platform’s needs.

What’s Included

• 1× Manley Performance Extreme Duty Stainless Steel Intake Valve (for each cylinder)
• 1× Manley Performance Extreme Duty Stainless Steel Exhaust Valve (for each cylinder)
• Installation instructions included

Installation & Compatibility

Installing these valves is recommended for experienced enthusiasts or professional mechanics familiar with Subaru engine rebuilds. The process involves removing the cylinder head, replacing the existing valves, and performing proper valve seat and seal checks. Tuning adjustments may be necessary to optimize airflow and power delivery, especially in boosted applications. Verify compatibility with your specific model year and engine configuration before installation. While some DIYers with mechanical experience can handle this upgrade, professional installation ensures proper setup and maximum longevity.

• Professional Installation: Recommended for best results
• Modifications Required: None beyond standard engine rebuild procedures
• Verify Compatibility: Confirm fitment for your specific Subaru WRX or STI model and year