Howards Cams Hydraulic Roller Rattler Camshafts are built for high performance and deliver "choppy" or "lopey" idle exhaust sounds. These rattler camshafts provide excellent throttle response through wider lobe centers and aggressive ramp rates. To achieve the perfect exhaust note, your car should be equipped with a quality dual exhaust system that does not include a cross-over, as the crossover will dampen the exhaust sound created by Howards Cams Hydraulic Roller Rattler Camshafts.