AFM Normally Aspirated Power Pipes® were developed because of the need for higher volume, better flowing intake pipes needed with the higher RPM 4.6/5.0 and the bigger cubic inch 347/408. With the volume of air these engines need, the small factory rippled intake pipes are too restrictive and the cold air intake pipes are too small of volume. They rely on the cooler intake charge to gain H.P., which cannot be chassis Dyno tested. AFM dyno's each Power Pipe® to verify H.P. gains. The mass air is in the inner fenderwell, but we do not rely on the cooler intake to make the extra H.P. We do it in design and testing.