Top Mount Intercooler - Subaru 99-00 GC8 WRX/STI

The Process West Top Mount Intercooler for the 1999–00 GC8 WRX and STI was developed with a single goal: to be the very best aftermarket top mount intercooler for the platform, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The ducting problem nobody else solves.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means a significant portion of the new core receives no ambient airflow whatsoever. It is a pointless exercise.

The Process West solution is a purpose-built bonnet splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow. Combined with the intercooler, it is the most complete and capable top mount intercooler option available for the GC8.

Largest core on the market.

At 490 x 175 x 90mm, the Process West core is by far the largest top mount intercooler available for the GC8 platform. The 90mm core thickness is a deliberate engineering choice, balancing maximum cooling surface area with the airflow resistance characteristics of a bonnet scoop mounted intercooler, delivering lower outlet temperatures and more power where it counts.

The definitive top mount intercooler upgrade for the Subaru GC8 WRX and STI.

Installation guide: View install guide