Process West Black Top Mount Intercooler w/ Shroud Subaru STI 2004-2005 | PWTMIC05B-KIT

Product Fitment:

2004-2005 Subaru STI

The Process West Top Mount Intercooler Kit for the 2004-2005 Subaru STI is engineered to be the ultimate no-compromise cooling upgrade for the platform. Rather than simply increasing core size, this system addresses the real limitations of factory and aftermarket intercooler designs—delivering consistent power, lower intake temps, and true real-world performance gains.

The Ducting Problem—Solved Properly

Most aftermarket intercoolers fail to address a critical issue: factory ducting does not match larger cores. This results in up to 50% of the intercooler receiving no airflow, drastically reducing effectiveness.

Process West solves this by including a purpose-built splitter, precisely matched to the upgraded core. The result is 100% airflow coverage across the entire intercooler surface, maximizing cooling efficiency where competitors fall short.

Optimized Core Thickness (90mm)

Bigger cores often hurt performance due to airflow restriction—especially in top mount setups where air must already change direction through the hood scoop.

Process West engineers determined that 90mm core thickness provides the ideal balance of:

• Maximum cooling surface area

• Minimal airflow restriction

• Improved heat exchange efficiency

This optimized design results in lower outlet temperatures and more consistent power delivery.

Balanced Y-Pipe Design

Unlike conventional Y-pipes that distribute airflow unevenly, the Process West system features a precision-engineered Y-pipe that evenly distributes charge air across the entire width of the intercooler core.

This ensures:

• Consistent cooling across both sides

• Improved airflow efficiency

• Better overall performance

Proven Performance Gains (Dyno Tested)

Under identical testing conditions, the Process West system delivered measurable improvements:

• Power Output:

  • Process West: 115.5 kW

  • Factory: 107.5 kW

• Intercooler Outlet Temps (Single Run):

  • Process West: 51°C

  • Factory: 66°C

• Heat Soak Test (Multiple Runs):

  • Factory Intercooler: Up to 84°C and rising

Real-World Street Performance

Real driving conditions show the true advantage:

• Process West System: ~43°C max under aggressive driving

• Factory Intercooler: ~72°C and climbing

This translates to:

• More consistent horsepower

• Reduced heat soak

• Improved throttle response

• Better tuning reliability

Key Features:

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

• 90mm optimized core thickness

• Purpose-built splitter for full airflow coverage

• Even charge air distribution with engineered Y-pipe

• Dramatically reduces intake air temperatures

• Proven power and thermal performance improvements

Performance Benefits:

• Lower intake air temperatures

• Increased and consistent power output

• Improved throttle response

• Reduced ECU timing pull under load

• Ideal for street, track, and tuned applications