This exhaust still remains the best exhaust available for Spec Miatas. It routinely produces more HP and Torque than all of its competitors. This exhaust was original developed by Sam henry of Springfield Dyno. Since taking over the line exclusively, East Street Racing have addressed the fitment issues and now the exhausts fit perfectly without touching anything. They also changed the hangers to bullet tips so they are retained much better by the exhaust hangers. These exhaust systems were run on six of the last 7 national championship winning cars. They have no equal.