aFe MACHForce XP Exhaust Cat-Back 2in SS-304 Cat-Back Exhaust for 05-08 Porsche Boxster S (987.1) H6aFe is proud to introduce the aFe MACH Force Xp cat back exhaust system for the 2005 2008 Porsche Boxster S and 2006 2008 Cayman S (987. 1) that uses the OE tip. In recent testing with the OE tip, this exhaust system resulted in a max gain of 22 horsepower and 30 lbs. x ft. of torque. aFe spent countless hours of R& D to develop the perfect balance of pure, race inspired performance and in cabin driving comfort and excitement of exhaust sound and tone