Process West’s goal when developing their top mounted intercooler was to make it the very best aftermarket top mounted intercooler for WRX/STi… period.
They studied the competitors’ products and fixed all of the mistakes they observed…some of them major.
The most obvious error problem is not supplying their intercooler with proper ducting/shrouding to suit the increased size of the new intercooler. There is no point in installing a larger intercooler and leaving the factory under bonnet splitter/shroud in place. A properly sized splitter/shroud to suit the application is the solution.
The next major problem is building an intercooler that is too thick. They say that bigger is better, but this i not the case with an intercooler that is mounted at 90 degrees to the ambient air flow.
For good heat exchange to take place you need good ambient airflow through the intercooler. In the case of the boxer engine with its intercooler mounted under a bonnet scoop the ambient airflow speed is already struggling after doing a 90 degree turn through the scoop. The last thing it now needs to do is find its way through 114mm (4.5in) of intercooler core. This will result poor heat exchange and high inlet temps.
The Process West intercooler is 90mm thick (3.5in) and in turn the intercooler breathes better, gives lower outlets temps and in turn makes more power.
Many aftermarket Y-pipes exhibit uneven charge air flow along the intercooler. Some of those Y-pipes consist of one high-flowing section with an afterthought spout as the second duct. The Process West kit includes a flow-balanced Y-pipe for even and consistent flow through both sides of the intercooler core.
Black finish intercooler core.
Fits all 2002-2007 Subaru WRX and 2004-2007 WRX STI; please look carefully at the car selection before placing your order.