Process West Black Top Mount Intercooler Kit MY08-18 STI

Top mount intercooler kit for the MY03-05 WRX/STI, developed to be the best aftermarket top mount intercooler for these cars.

A larger intercooler needs ducting/shrouding sized to suit it. There is no point in fitting a larger intercooler and leaving the factory under-bonnet splitter/shroud in place.

Core thickness matters as well. A top mount intercooler sits at 90 degrees to the ambient air flow, and good heat exchange needs good airflow through the core. On a boxer engine with the intercooler under a bonnet scoop, the air has already slowed after a 90 degree turn through the scoop. A 114mm (4.5in) thick core makes it harder for that air to get through, which results in poor heat exchange and high inlet temperatures.

This intercooler is 90mm (3.5in) thick, so the core breathes better, outlet temperatures are lower and power is higher.