Boosting Performance with Better Cooling

Your Subaru's turbocharger crams more air into the engine for extra power. But compressed air gets hot, reducing its effectiveness. The top-mount intercooler (TMIC) cools this hot air before it enters the engine. Upgrading your TMIC can potentially increase horsepower by around 15HP (results may vary with tuning).

TMIC Considerations:

• Stock TMIC Capacity: Stock TMICs on WRX models can handle up to 300WHP, and STI models can handle up to 400WHP (with tuning). However, upgrading can offer performance benefits.
• TMIC Options: Many aftermarket TMICs are available, but there's no single "best" brand. Focus on quality and features that suit your needs.
• 2008-2009 Models: These models have a different engine bay layout, so ensure your chosen TMIC is compatible.
• Construction: TMICs come in two main types: tube-and-fin and bar-and-plate. Both have pros and cons, but there's no clear winner in terms of performance. Bar-and-plate may be more resistant to damage.

Beyond the Basics:

• STI/JDM Intercoolers: JDM STI intercoolers offer a slight size increase over USDM models.
• TMIC Size: Bigger isn't always better. Choose a size that balances performance gains with potential drawbacks.
• TMIC Heat Soak: TMICs can heat soak during stop-and-go traffic, reducing their effectiveness.

Combating Heat Soak:

• Heat Shielding: Heat shields reflect heat away from the TMIC, reducing heat soak. Several aftermarket options are available.
• Turbo Insulation: Insulating the turbo traps heat inside, improving efficiency and reducing heat soak on the TMIC.

Hidden Costs:

• Intercooler Piping: Some TMICs include new intercooler piping, while others don't. Factor this into the cost.

Maximizing Efficiency:

• Larger Hood Scoop: A larger hood scoop ensures sufficient airflow reaches the TMIC for optimal cooling.
• Ducting/Shrouding: Proper ducting channels air from the scoop directly through the TMIC core. Aftermarket options exist.
• Air Splitters: Air splitters help distribute airflow evenly across the TMIC core.

Advanced Efficiency Options:

• Water Spray Kits: These kits inject water mist onto the TMIC for additional cooling, especially effective against heat soak.
• Nitrous/CO2 Spray Kits: Aftermarket kits use nitrous or CO2 for even more aggressive cooling (consult a mechanic for safe installation).

Installation and Tuning:

• Installation: Installing a TMIC is a relatively simple process and can be done by mechanically inclined DIYers. Allow around one hour. 
• Tuning: Tuning is recommended to maximize the benefits of your upgraded TMIC, especially if you modify other engine components.

Remember: Consult a qualified mechanic to choose the right TMIC for your Subaru and ensure proper installation and tuning for optimal performance.