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.