Before you can understand how the Thunderheader™ works, you should have some insight on the dynamics of exhaust pulsing. It is important to know that the exhaust exits as long columns or pulses of spent gases, and at peak RPM, the pluses can reach velocities of about 300-350 feet/second, and a frequency of about 3,000 per minute. This means the pulse must go from 0 to 200 mph & back to 0, about 3,000 times per minute. Thunderheader™ head pipes have been tuned to the proper length & diameter, to produce maximum horsepower, and a excellent torque curve. In addition to “tuned” head pipes, a patented collector is used. The collector is designed to direct spent gases through four acoustical dampening chambers