As the engine in your Chevrolet Corvette operates, two cylinders fire within 90 degrees of each other for every turn of the crankshaft. This happens two times during the firing order, which means that the two cylinders expel exhaust gas into the same exhaust manifold at nearly the same time. Multiply this by six for the other cylinders and you can begin to imagine the backpressure, often resulting in reduced torque, less horsepower, and fuel inefficiency, making for an unhappy Chevy Vette.
H- vs. X- Pipe Cross Over Systems
In our illustration above, imagine that while the two cylinders are
firing almost simultaneously in one bank of cylinders, there is
relatively little going on in the other bank of cylinders. With a
standard H-pipe cross-over configuration, a little of the excess
pressure is allowed to go over to the side — where not much is
happening. This can provide some pressure and pulse reduction and can
help improve your Corvette’s low and mid-range torque. Adding a
crossover pipe in the H configuration that has a larger diameter but is
shorter in length can help even more.
An X-pipe offers a crossover design that allows the pressure from both
banks of cylinders to be more equal. It does this by forcing the
exhaust stream to cross over in a criss-cross pattern. The result is
pressure that is more equal and pulse-free using both manifolds. Less
pressure and pulsing can mean more horsepower and torque, and better
overall engine performance.