Hedman X-Treme Exhaust Equalizers
The Science Behind The X-Pipe
The firing order of all production V8 engines, regardless of make, has one cylinder in each bank that will fire within 90° of crankshaft rotation of another cylinder in the same bank. This occurs twice during completion of the entire firing order. These two cylinders will be exhausting almost simultaneously into the same manifold system. Full-length 4-tube headers help separate these pulses until the collector is reached. After the header tubes dump into the collectors, the two cylinders again are fighting each other for space in the collector and exhaust pipe. The result is reflected pressure waves traveling back up the exhaust system, backpressure, lost power, and poor economy.
At the same time two cylinders exhaust in one bank, there is no activity in the opposite bank. The traditional H-pipe equalizer allows some of the excess pressure to bleed over the "quiet side" of the exhaust system, resulting in some low and mid-range torque improvements. At high RPM, however, the gases cannot bleed across the H-pipe fast enough to help power significantly. Hedman's X-TREME Equalizer Pipe splits the flow in the crossover junction so the pressures on both banks will be equal and pulse free after the crossover regardless of RPM. Volumetric efficiency and power are therefore improved at all engine speeds.