Process West Billet Intake ManifoldThe Process West range billet manifolds is a no holds barred manifestation of what is possible under the hood of a WRX STI when perfect aesthetics meet high end performance. What you see here is the result of years of research and testing, multiple prototypes and a ground up fully featured design process that makes this a key asset of our product range. Available in two major configurations they feature a full billet plenum with generous billet bell