IAG Performance Equal Length Header & Uppipe – Subaru Models (Inc. WRX 2002-2014 / STI 2004+)

IAG Equal Length Header and Up-Pipe — 2002-2014 Subaru WRX / 2004-2021 STI

Maximum Scavenging Efficiency for High-Power EJ Builds
The IAG Equal Length Header and Up-Pipe package uses an equal length primary tube design that optimizes exhaust scavenging by ensuring all four cylinders contribute equal pulse timing to the turbocharger inlet. Equal length headers provide more uniform turbocharger spool characteristics and are preferred for maximum power extraction in high-performance applications. Stainless steel construction with mandrel bends and increased piping diameter.

DETAILS

• Equal length header design — optimizes exhaust scavenging and turbocharger spool
• Durable stainless steel construction on both header and up-pipe
• Smooth mandrel bends
• Increased piping diameter vs OEM
• Includes 3-bolt up-pipe
• Increases horsepower and torque
• Reduces turbo lag
• Lighter than OEM cast exhaust manifold
• Includes zinc-plated hardware and exhaust gaskets
• Note: equal length header does not produce the characteristic Subaru boxer rumble
• Fits: 2002-2014 WRX / 2004-2021 STI

Equal vs Unequal Length: The Trade-Off
The equal length design ensures each cylinder’s exhaust pulse arrives at the turbocharger with equal timing, creating a more consistent pressure wave for the turbine wheel. This typically produces more linear spool and slightly improved top-end power compared to an unequal length design in high-power applications. The trade-off is the loss of the characteristic Subaru boxer rumble, which is produced by the unequal pulse timing of an unequal length design.

When to Choose Equal Length
Equal length headers are preferred for maximum high-power output applications — time attack, drag racing, and competition builds where peak power and consistent spool characteristics are the priority over the exhaust note character.

Stainless Construction and Complete Package
Like IAG’s unequal length header, the equal length version uses stainless steel construction with mandrel bends and includes the up-pipe, new gaskets, and all required hardware.

Why Choose IAG Performance

IAG Performance has been building Subaru-specific engine and drivetrain components since 2001, and in that time they have become the standard by which serious Subaru builds are measured. Based in Westminster, Maryland, IAG designs, machines, and assembles their products in-house using Haas CNC equipment and their own engineering team. Their catalog spans everything from short blocks and long blocks rated to 1150 BHP all the way down to the fuel system, oiling, and drivetrain hardware that keeps modified Subarus running reliably for years. Every IAG product exists because a problem needed a better solution than what was available — and the engineering shows.

The RallySport Take

The IAG Equal Length Header is the header choice for the driver who prioritizes maximum performance over the Subaru exhaust note. For a competition vehicle or a build focused on peak power extraction, equal length is the correct specification.

Fitment