Product Fitment:
2002-2005 Subaru WRX
The Process West Street Billet Intake Manifold is a premium, motorsport-derived induction upgrade designed for the 2002–2005 Subaru WRX and STI. Engineered without compromise, it delivers exceptional airflow performance while maintaining the drivability and comfort required for street use.
Developed through extensive research, prototyping, and real-world validation, this manifold represents one of the most advanced intake manifold solutions available for the Subaru platform.
Built Without Limits
Each manifold is CNC machined from solid billet aluminium, ensuring maximum strength and precision where it matters most.
Key construction features include:
- Full billet aluminium CNC-machined design
- Generous bell-mouth runner entries for improved airflow
- Thick-wall polished mandrel-bent tube sections
- High-quality TIG-welded assembly
- Rated to 100psi boost pressure capability
This level of construction delivers rigidity and durability far beyond cast or fabricated alternatives.
Street-Focused Performance Design
The Street Billet version is specifically engineered to maintain strong everyday drivability while improving overall engine performance.
It features:
- Optimized plenum volume for balanced airflow distribution
- Runner length tuned for strong low and mid-range torque
- Continued power delivery into higher RPM range
- Retention of factory air conditioning compatibility
This makes it ideal for performance street builds that still require comfort and usability.
Proven Performance Gains
Extensive testing has shown consistent improvements across multiple setups:
- Approximately 9% gains in torque and horsepower on stock configurations
- Similar gains maintained on heavily modified engines running E85
- Effective across a wide range of turbo, fuel, and engine setups
Key Features:
- CNC billet aluminium construction
- Rated to 100psi boost pressure capability
- Optimized plenum and runner design
- Improved low and mid-range torque response
- Maintains factory air conditioning compatibility
- Supports stock and modified engines
Performance Benefits:
- Increased airflow efficiency
- Improved throttle response
- Stronger torque delivery across RPM range
- Enhanced top-end power capability
- Improved engine breathing under boos
