GReddy Supreme SP CatBack Exhaust System Subaru Base 2015 2021 GReddy Supreme SP Cat Back Exhaust for VA Subaru WRX STi GReddy Revolution RS Cat Back Exhaust Subaru WRX STI 2002 2007 101 GReddy Supreme SP Catback Exhaust System Subaru STI WRX Hatchback. Supreme SP Cat Back Exhaust by Greddy The Supreme SP much larger diameter piping, resonators and mufflers, but also smoothest the layout for maximum performance with good sound suppression. This cat back exhaust starts out with a full 3 mid pipe with a large straight through resonator to tune out drone. The next section smoothly transitions into dual 2. 5 diameter piping. Improved dual GReddy straight through mufflers with dual, double wall tips on each muffler finish off the exhaust. GReddy designers carefully position the dual mufflers and staged tips to flow with the GV chassis bodylines. Like all GReddy Supreme SP systems the fully hand welded 304 Stainless Steel exhaust. Features Cat back, dual muffler system A full 3 mid pipe with a large straight through resonator Specifications Number of pieces: 4 Piping: 76 mm (3") 2x 63. 5mm (2. 5") Tip(s): 4x 89 mm (3. 5") Gasket(s): 2x 2. 5" & 1x 3" oval (qty: 3 included) replacement(s) Resonator: Yes Sound level: L89 & R91 dB(a) @4000 Applications 2011 2014 Subaru STI Sedan What's In The Box? Supreme SP Cat Back Exhaust