Heres the explanation of why it works. Another MAC first! MAC's new patented PRO CHAMBER™ has just made the competition’s H-pipe and X pipe technology obsolete! Split (one on each side) manifolds or exhaust headers on any engine need to be balanced to each other. On a V-8 motor for example, exhaust pulses enter respective collectors at uneven intervals of 90-180-270 degrees of engine rotation. This process hampers the full benefit of any exhaust header or manifold system, by the long intervals between exhaust pulses, making the balancing of exhaust mandatory for optimum power. Balance tubes between exhaust on opposite sides, helps to transfer exhaust pulses from side to side, to smooth out exhaust pulse and flow, resulting in more power and economy. MAC's PRO CHAMBER™goes even further than traditional H-pipes to produce more torque and horsepower, by merging exhaust pulses in one area. Merging of all exhaust gasses creates higher temperatures, which in turn creates a boost in exhaust velocity and lets exhaust gas see both outlets.