Borla(r) Performance offers a quad-exit Cat-Back(tm) exhaust for the venerable 2008-2014 Subaru WRX STI. This race-inspired system (PN140312) checks all the boxes on every Subaru enthusiasts hit list taking this flagship to an even higher realm of performance. For starters Borla(r) engineers upgraded the Stir's exhaust plumbing from 2.5" to 3" in diameter. The resulting increased airflow through the turbocharged powerplant provides horsepower gains of 7% - 10%. Hardcore enthusiasts who add Stage 1 or 2 chip upgrades will find this boost to the Stir's lung capacity vital to unlocking the ECU's full potential. Drivers negotiating terrain from rally course jumps to shopping mall speedbumps will appreciate how Borla(r)'s R&D fabricators found room to tuck the system muffler higher than the OE exhaust providing a 1.75" clearance gain. This additional room also enhances rear-section aerodynamics and improves appearance by reducing clutter. Besides being higher it's lighter. Thanks to Borla(r)'s patented straight-through design that eliminates power-robbing baffles and chambers the STI sheds approximately 8 lbs. making it a bit leaner meaner in a class where every bit counts. True to form the exhaust amplifies and enhances the Stir's distinctive rumbling gurgle with the rich bass of Borla(r)'s trademark sound of power. Combined with high-quality T-304 stainless steel construction and double-walled rolled-edge polished T-304 stainless steel tips drivers get the sound and looks they expect from the world's most winning exhaust. Borla(r) the original pioneers of high-quality stainless steel free-flow exhaust utilizes patented award and race winning technology to deliver quality sound and performance gains. All with an easy bolt-on installation and backed by a solid Million-Mile Warranty on all street systems.