Invidia Equal Length Race Exhaust Manifold - Subaru Models (Inc. 2005-2021 STI / 2008-2014 WRX)

Equal Length Race Manifold: The Foundation for 600+ HP EJ Builds

The Invidia Equal Length Race Exhaust Manifold for the 2008-2014 Subaru WRX STI is designed for the upper end of EJ performance builds — the component that replaces the factory unequal length manifold when the factory unit becomes the exhaust restriction on high-horsepower builds. Invidia rates this manifold for 600+ HP applications. The equal length primary design eliminates the cylinder-to-cylinder pulse timing variations of the factory manifold and produces a 4-cylinder exhaust note in place of the characteristic Subaru boxer rumble.

Equal Length Primaries — Consistent Pulse Timing at the Turbine

The factory EJ exhaust manifold is unequal length — cylinders 3 and 4 have significantly longer primaries than cylinders 1 and 2. At moderate power levels this is acceptable, but as boost and exhaust flow increase, unequal pulse timing creates interference at the turbocharger inlet and limits scavenging efficiency. The Invidia equal length design ensures all four cylinder pulses arrive at the turbine simultaneously — improving scavenging efficiency, eliminating inter-cylinder interference, and supporting the power levels a high-output EJ build requires.

2-Bolt Up-Pipe Flange — For External Up-Pipes and Rotated Setups

The manifold uses a 2-bolt up-pipe flange for use with an external-style up-pipe or rotated turbo setups. Built-in O2 sensor bung included for ECU compatibility. Important fitment notes: 2002-2005 WRX may require STI oil pan. 2006-2007 WRX requires STI oil cooler and STI oil pan. Verify clearances for your specific application before ordering. A tune is required after installation.

Key Features

• Platform: 2008-2014 Subaru WRX STI
• 304 stainless steel equal-length construction
• 2-bolt up-pipe flange — for external up-pipe or rotated turbo setups
• Built-in O2 sensor bung
• Designed for 600+ HP applications
• Eliminates unequal pulse timing of factory manifold
• Changes exhaust note from boxer rumble to 4-cylinder character
• Tune required after installation

Fitment Notes

• Platform: 2008-2014 Subaru WRX STI
• 2002-2005 WRX may require STI oil pan
• 2006-2007 WRX requires STI oil cooler and STI oil pan
• Tune required after installation
• Verify clearances for your specific engine build before ordering

Straight From Subispeed

The Invidia equal length manifold is for GR STI builds that have addressed everything else and are now targeting the manifold as the next restriction. This is a high-power build component — not an early upgrade purchase. The trade-off is real: the equal length design eliminates the Subaru boxer rumble that many owners consider part of the car's character. For a 600+ HP performance build, that trade-off is worth it. For a build where the boxer sound matters, it is not.

What's Included

• Invidia Equal Length Race Exhaust Manifold
• New exhaust manifold studs
• NOTE: 2002-2005 WRX may require STI oil pan. 2006-2007 WRX requires STI oil cooler and oil pan.

About Invidia

Invidia is a Taiwanese performance exhaust manufacturer with a strong following in the Subaru, Mitsubishi, and Japanese sports car communities. Their catalog covers cat-back exhausts, downpipes, headers, manifolds, and full exhaust systems built around SUS304 stainless steel construction with CNC-machined flanges and direct OEM fitment. Invidia exhausts are among the most widely installed aftermarket systems on Subaru platforms globally — well-documented, well-supported, and proven across thousands of street and track builds. Subispeed carries the full Invidia lineup because their combination of quality construction, fitment accuracy, and range of tip and finish options makes them the exhaust brand we recommend to Subaru owners at nearly every power level.