When it comes to performance, there is one steadfast rule: All the good air that goes into making horsepower must eventually find its way out. This means that adding all the cool camshafts, intake manifolds and even superchargers to help improve airflow into the motor will be useless (okay, maybe not useless, but certainly much less effective) if the motor is not able to rid itself of the exhaust. Cork up a serious performance motor and watch it struggle and gag on its own exhaust fumes.








