The goal for the Process West Top Mount Intercooler was simple. Engineer the best-performing aftermarket top-mount on the market. By studying the common failures in the aftermarket, like poor ducting and inefficient core thickness, we built a cooling solution that sets a new standard for the Subaru platform. This TMIC does not include a splitter, though we strongly recommend running one. See our other models that include vehicle-specific splitters. What's included Process West 90mm intercooler coreHigh-flow moulded silicone Y-pipeMounting hardware and fittings Optimal core thickness: 90mmMany competitors push 114mm (4.5") cores on a "bigger is better" pitch. For a top-mount, where air has to make a sharp 90 degree turn through a bonnet scoop, too much thickness just creates resistance. Our design uses a 90mm (3.5") core. The air breathes through the core instead of hitting a wall. The result is lower outlet temps and more consistent power. High-flow silicone Y-pipeStandard aftermarket Y-pipes often push air unevenly, favouring one side of the core. Our custom-moulded silicone Y-pipe is built for even charge-air distribution across the entire entry tank. Proven performanceDyno testing is notoriously hard for top-mounts due to limited scoop airflow. Even so, back-to-back testing on our '05 WRX against the factory unit returned clear gains. Power: 115.5kW, up from the factory 107.5kW. Thermal control: the PW unit peaked at 51 degrees C in static dyno conditions, against 66 degrees C for the stock unit. Under three back-to-back runs to simulate heavy load, factory outlet temps climbed to 84 degrees C. The Process West unit stayed far more stable. Out on the road is the real test. During spirited mountain driving, the stock intercooler peaked at 72 degrees C and kept climbing, with a noticeable loss of liveliness. The Process West system never exceeded 43 degrees C.
