ISR Performance Series II - GT Single Exhaust System - Non Resonated - 95-98 Nissan 240sx (S14)IS S2GTNR S14 ISR Performance Series II GT Single Exhaust Nissan 240sx 95 98 (S14) The ALL New ISR Performance Series II GT Single exhaust is an incredibly stylish and aggressive exhaust system at an affordable price. Constructed of high quality stainless steel, the GT Single utilizes 3" piping for the mid pipe and the majority of the rear section before expanding to a 5" Round Muffler with a 4. 5' extended tip.. Utilizing our all new Series II