The secret to having a powerful engine is quickly getting air into the engine and back out again. The ram air scoop forces air into the engine, necessitating a quick outlet for the air as well. First, we put port plates in the exhaust ports, narrowing the outlet (to remove the pocket of stalled air that 4V heads are notorious for), thus increasing the velocity of the airflow. We also added a set of custom made 180° exhaust headers. These headers are designed to keep all pipes flowing by drawing off of each other. This crossover effect creates a constant flow of air through the Stainless Steel Borla Collector mufflers.