What Is the Difference Between X-Pipe and H-Pipe?

Exhaust systems usually contain one of two exhaust pipes, either an H-pipe or an X-pipe. In general, the X-pipe provides higher performance because of its design.

Noise

The X-pipe is 8 decibels quieter than the H-pipe, on average. This is because the X-pipe smooths exhaust pulses better than the H-pipe.

Exhaust

In an H-pipe, exhaust gases tend to flow straight out of each pipe. In an X-pipe, the two exhaust paths meet at an intersection causing the gases to mix.

Flow

The H-pipe encourages gases into a tumbling flow. The X-pipe promotes a laminar flow, which results in a quieter and steadier flow of gases through the exhaust system.

Horsepower

Since the X-pipe allows exhaust gases to flow better, it allows more torque and therefore more horsepower than the H-pipe. This is because the exhaust gases flow more readily out of the engine so they do not build up and cause pressure to build up inside the system.

References

• Car Craft: H-Pipe, X-Pipe, 1, 2, 3...