www.fvd.net Video of the FVD Exhaust for the Porsche ® 2014 + 981 (3.4L) Cayman / Cayman S / Boxster / Boxster S. FVD Part # BES 981 150 00S. This is our Best Selling Sport Muffler for the 981 to date. Our mufflers are uniquely made with double perforated sound absorption tubes. The acoustic silencer absorption tubes are made in a trapezoidal pattern and are perforated with varying diameters, which isolate and dampen the unwanted frequencies that create drone. These perforated tubes present much less flow restriction than baffle plates at higher gas velocities, and consequently translates into larger horsepower gains (+ 11 crank Hp & + 10 crank torque ) at higher RPMs. The resulting sound exhibited is an aggressive, linear, firing-order dominated flat 6 Porsche ® sound, which is the closest to a Cup Car in nature without all the decibels.