Process West Intake Manifold Street Version Subaru STI 2004-2021 | PWIM002

Product Fitment:

2004-2021 Subaru STI

The Process West Billet Intake Manifold range represents the pinnacle of design, engineering, and performance for Subaru WRX and STI platforms. Born from years of R&D, extensive testing, and countless prototype iterations, this manifold is the result of a no-compromise approach to performance and aesthetics.

Crafted for both street and race applications, the manifold is available in multiple configurations to suit a wide range of Subaru platforms—from MY99 GC8 to the latest WRX and STI models. The modular design allows compatibility with stock throttle bodies or 3” Hypertune billet throttle setups. Custom throttle flanges are also available on request.

Key Features:

• Fully CNC-Billet Plenum & Bellmouths: Features a high-volume billet plenum and precision-machined bellmouths for optimal airflow and velocity.

• High Boost-Ready Construction: Built using thick-wall, polished CNC mandrel-bent tubing and TIG-welded to withstand up to 100 PSI of boost.

• Modular Design: Available for various Subaru generations and configurations, including stock or Hypertune throttle compatibility.

• Optimized for Torque & Top-End Power: Runner length and plenum volume are engineered for strong low/mid-range torque while unlocking high-rpm performance.

• Retains A/C Compatibility: Despite the large plenum, the Street version is fully compatible with factory air conditioning systems.

• Tested Performance Gains: Expect ~9% power and torque gains on both stock and heavily modified engines—including those running E85.

• Street or Race Options: The Street version offers aggressive performance with full drivability. For more high-rpm power, shorter billet TGVs (lower runners) can be supplied.

This intake manifold is not just a performance upgrade—it's a statement piece for serious Subaru builders. When only the best will do, the Process West Billet Intake Manifold delivers strength, flow, and performance that outclass every alternative on the market.