Since mid-1964, Mustang has always been about muscle, looks, and loads of customization options. Borla(r)'s lineup for the Mustang GT and Shelby GT500 lives up to this legacy, with systems to meet a wide variety of performance goals and budgets. For soundaholic Mustang GT drivers who won't settle for anything less than unbridled performance with a pure, aggressive pony car growl, Borla(r) offers a Cat-Back(tm) (PN140318) and Axle-Back (PN11777) system, each featuring Borla(r) S-Type mufflers. Both are also available with Borla(r)'s more sound-absorbing Touring mufflers (PN140319) and (PN11778), for sleeper fans who prefer to be more subtle about their power upgrades. Responding to the high-output exhaust needs of the supercharged 2010 Shelby GT500, Borla(r) engineers developed a specially-tuned Multicore Cat-Back(tm) system (PN140320) which includes an X-Pipe. Borla(r)'s patented high-velocity Multicore design distributes exhaust gases through multiple straight-through perforated cores. A race-tested innovation, Multicore technology is also utilized in Borla(r)'s elite XR-1 mufflers used by winning teams in NHRA, Baja 1000 and many other racing venues, and has been proven to actually outflow a straight pipe. System features high-quality T-304 austenitic stainless steel construction, ultra-smooth mandrel-bent 2.5" tubing, flawless welding from master craftsmen, dual 4" diameter angle-cut rolled edge 12" long bright chrome on T-304 stainless steel tips, and an unrivaled Million-Mile Warranty. From the dimensions and perforation patterns of the inner cores to the amount of composite filament packing, all specifications of Borla(r) mufflers are tuned on a vehicle-by-vehicle basis for an optimum blend of performance and sound. Combined with distinctive motorsport styling, easy bolt-on installation and enhanced fuel economy, the world's most winning exhaust continues to lead the industry it founded over 40 years.