The 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 their product range. Available in two major configurations they feature a full billet plenum with generous billet bell mouths and thick wall polished CNC mandrel bent tube components. High end TIG welding assembly makes them suitable for up to 100psi boosted applications. No other product comes close to this level of strength and detail. The range is modular to suit everything from MY99 GC8 to the latest WRX and STI's with any stock throttle or that to suit the 3" Hypertune billet throttle.