Stainless Steel Exhaust Header for Subaru Impreza WRX (2006-2007) & WRX STI (2004-2007) 2.5L

High-Flow Stainless Steel Exhaust Header for 2006-2007 Subaru WRX,WRX STI (GD/GG)

What it Does: The Stainless Steel Exhaust Header replaces the restrictive factory cast iron manifold on 2006-2007 Subaru WRX and WRX STI models to decrease backpressure, accelerate turbo spool, and enhance cylinder scavenging.

The Stock Subaru WRX,WRX STI Exhaust Manifold Restriction

Factory exhaust manifolds installed on the EJ255 and EJ257 boxer engines utilize heavy cast iron runners with rough internal casting flash and inefficient merge junctions. This rough internal surface creates boundary layer drag and turbulence right at the exhaust ports. Furthermore, the OEM manifold's restrictive collector design retains excessive thermal energy near the cylinder heads, worsening heat soak and generating high pre-turbine backpressure that dampens transient throttle response and delays boost threshold.

The Engineering Solution

Constructed from mandrel-bent T-304 stainless steel, this tubular performance manifold eliminates flow bottlenecks with 1.5-inch primary runners routing smoothly into a 2.0-inch collector. The tuned geometry synchronizes exhaust pulse scavenging, lowering pumping losses and driving exhaust gases directly into the up-pipe via a rigid 4-bolt flange. Precision CNC-machined, warp-resistant thick flanges deliver a reliable high-temperature seal against the boxer cylinder heads, while the corrosion-resistant polished finish withstands aggressive thermal expansion cycles without structural fatigue.

What's Included

• 1 Exhaust Header
• 3 Gaskets
• Mounting Bolts and Nuts

Technical Specifications

Compatibility

• 2006-2007 Subaru Impreza WRX 2.5L EJ255 Turbo
• 2004-2007 Subaru Impreza WRX STI 2.5L EJ257 Turbo

Frequently Asked Questions & Fitment Warnings

Does this fit the GD/GG WRX,WRX STI?

Yes, this is a direct fit for the 2006-2007 Subaru WRX,WRX STI equipped with the EJ255 and EJ257 engine; it is not compatible with naturally aspirated 2.5L Impreza models.

Do I need to re-torque the header hardware after installation?

Yes, it is strongly recommended to re-torque all header-to-head and up-pipe flange hardware after the initial heat cycles to prevent exhaust leaks caused by metal thermal expansion.

The Subaru Boxer Caliber

Maximize the unmistakable boxer exhaust note and free up high-RPM power with high-velocity primary tubing designed for rugged durability under extreme boost levels.