The PERRIN Fuel Pressure Regulator is designed with adjustability and high-flow fuel regulation in mind that works with fuel systems ranging from stock setups to 1000+ horsepower setups and the best option to fix the stumbling issue present in vehicles. *HIGH-FLOW* Of the (6) -6 ports on the Adjustable Fuel Pressure Regulator, (4) of these ports are used to connect to your fuel rails with maximum flow in mind. Rated to 1,000+ horsepower worth of fuel flow, this kit works perfectly with stock engines as well as heavily modified engines thanks to the interchangeable orifices. *REPLACES PROBLEMATIC OEM REGULATOR/DAMPENER* The PERRIN Adjustable Fuel Pressure Regulator replaces the cumbersome and overly-complicated OEM fuel pressure regulator on your 2008-2015 STI. Removing the OEM part along with the two fuel pressure dampeners significantly reduces the common complaint from STI owners that their car stumbles around 3,000 rpm. After years of development, a design was settled upon that works for applications ranging from stock to heavily modified. *ADJUSTABILITY* The PERRIN Adjustable Fuel Pressure Regulator can be adjusted from 20 psi to maximum fuel pump capacity. This allows for added fuel delivery to your engine without recalibrating your ECU. Included are three interchangeable orifices for stock fuel pumps, larger drop-in pumps, and fuel systems supporting 1,000+ horsepower. *SIX PORTS FOR MAXIMUM FLOW* There are (6) -6 ports on the Adjustable Fuel Pressure Regulator: (1) for fuel pump feed, (2) for fuel rail feed, (2) for fuel rail return, and (1) for fuel tank return. This allows for easy installation of aftermarket fuel rail kits that utilize more than one rail. *DIRECT BOLT-ON* The PERRIN Adjustable Fuel Pressure Regulator is easy to install as it bolts right into the existing threads where the OEM fuel pressure regulator assembly is normally housed. Installation of this kit requires no special tools. *AUXILIARY PORT* Unlike competitors' fuel pressure regulators, the PERRIN Adjustable Fuel Pressure Regulator has a port located discretely on the bottom of its assembly. This 1/8th NPT threaded port allows for installation of aftermarket fuel pressure sensors and/or gauges. *CONSTRUCTION* Internal components protected under Patent # 6,298,828. These components are licensed to PERRIN Performance for the technology related to the Adjustable Fuel Pressure Regulator's features. Using this proven technology ensures internal components will last the duration of your vehicle's life. *FINISH* The PERRIN Adjustable Fuel Pressure Regulator comes with a black anodized finish to make certain your part continues to look good and resist corrosion during its use. For your convenience the ports are labelled according to their proper connections.