Process West Black Top Mount Intercooler w/ Shroud 2004-2007 Subaru WRX / 2006-2007 STI | PWTMIC04B-KIT

Product Fitment:

2004-2004 Subaru WRX

2006-2007 Subaru STI

The Process West Top Mount Intercooler Kit is engineered with one goal in mind—to be the ultimate top mount intercooler upgrade for Subaru WRX and STI models. Every aspect of the design has been refined to eliminate the common shortcomings found in typical aftermarket intercoolers, delivering consistent cooling, improved power, and real-world performance gains.

Engineered as a Complete System

Unlike many aftermarket options that simply increase core size, Process West delivers a fully integrated solution. This kit includes a purpose-built splitter and optimized Y-pipe, ensuring that 100% of the intercooler core receives direct airflow from the hood scoop.

Factory ducting is often mismatched to larger intercoolers, leaving significant portions of the core ineffective. Process West solves this with a properly sized splitter that maximizes airflow efficiency across the entire surface area.

Optimized Core Design (90mm Thickness)

Bigger isn’t always better. Many intercoolers are built too thick, restricting airflow and reducing cooling efficiency. Process West engineers identified the optimal balance with a 90mm thick core, delivering:

• Improved airflow through the core

• Reduced heat soak

• More efficient heat exchange

• Consistent intake temperatures

Balanced Y-Pipe Air Distribution

The included high-performance Y-pipe is designed to distribute charge air evenly across the entire intercooler core. Unlike conventional designs that favor one side, this system ensures consistent cooling and airflow efficiency across both banks.

Proven Performance Gains

Independent testing shows measurable improvements in both power and intake air temperatures:

• Power Increase:

  • Process West: 115.5 kW

  • Factory: 107.5 kW

• Intercooler Outlet Temps (Single Run):

  • Process West: 51°C

  • Factory: 66°C

• Heat Soak Resistance (Multiple Runs):

  • Factory Intercooler: Up to 84°C and rising

Real-World Street Performance

In real driving conditions, the Process West system consistently outperforms the factory setup:

• Process West: Max ~43°C under aggressive driving

• Factory Intercooler: Up to 72°C and still climbing

This translates to:

• More consistent power delivery

• Improved throttle response

• Reduced ECU timing pull

• Better reliability under sustained load

Key Features:

• Complete top mount intercooler system (core, splitter, Y-pipe)

• Optimized 90mm core thickness for airflow and cooling balance

• Purpose-built splitter for full airflow coverage

• Even air distribution with engineered Y-pipe

• Dramatically reduces heat soak

• Proven gains in power and thermal efficiency

• Designed for real-world street and track performance

Performance Benefits:

• Lower intake air temperatures

• Increased horsepower and consistency

• Improved throttle response

• Enhanced reliability under hard driving conditions

• Ideal for tuned and high-performance applications

2006-2007 WRX owners will need to use the older 2002-2005 BOV gasket with this intercooler.