The Cosworth Subaru High Volume Inlet Manifold is cast from aluminium featuring large tapered runners with radiused inlets for improved air flow. Plenum volume has been substantially increased and tuned for power. Engineered for easy installation and is the key to making big power. The Cosworth EJ257 plenum is designed for use with the 2004-2009 STI engines equipped with electronic throttle control.

The Cosworth High Volume Inlet Manifold replaces the factory Subaru plenum in vehicles equipped with an aftermarket front-mounted intercooler (FMIC) kit. Throttle body position remains stock, ensuring fitment with any brand FMIC kit designed for the stock throttle body and intake manifold.

• Substantially increased plenum volume.
• Large tapered runners with radius inlets.
• Tuned plenum volume and runner length/taper.
• Over 10% increase in flow.
• Integral vacuum manifold for connectionof brake booster, boost gauge, MAP Sensor, Boost Controller, etc.
• Stock throttle body location for compatibility with most aftermarket FMIC kits.
• Will work with standard or forward mount electronic throttle body configurations.

You will need to fabricate your own header tank bracket.