TMIC basics on a Subaru WRX/STi:

What are the hidden costs with TMICs? When switching to a larger TMIC, ensure you understand whether it comes with the intercooler piping or not. Some TMICs come bundled with it, some do not.

Once I have a larger TMIC, what steps are helpful to increase it’s efficiency?
1. Increase the size of your stock hood scoop to accommodate the increased TMIC surface area. Maximum efficiency of a TMIC depends on full air flow to the core. This generally means you should obtain a STi or aftermarket larger hood scoop.
2. Proper ducting/shrouding plays a large role as well. OEM and aftermarket options exist for intercooler ducting/shrouding. This step may require custom trimming to ensure a perfect seal or the addition of an alternate substance to make up the difference if needed. Many people have custom trimmed garage door weather stripping/sealer available from Home Depot or Lowes to fill up any gap between the ducting/shrouding and their TMIC. The end goal of ducting/shrouding is a complete seal between the TMIC and hood scoop. This ensures that 100% of the air entering the hood scoop passes through the TMIC core assembly.
3. Additionally, there are OEM and aftermarket options that exist for air splitters. Air splitters divide and route the air coming into your hood scoop over the entire core of the intercooler.

This thread will help you figure out what scoop/splitter to use.

What are the advanced efficiency options?
1. Waterspray. There are aftermarket and OEM options that provide increased cooling efficiency and combat against heat soak issues with TMICs.
2. NO2 and CO2 Sprayers. There are aftermarket kits that spray CO2 or NO2 to cool TMICs down and combat against heat soak issues with TMICs.

Where do I buy a TMIC? You can buy a aftermarket intercooler through amazon or your favorite vendor.