différence "X" pipe et "H" pipe

si tu comprend l'anglais voici une description des deux style. H Pipe:

An H pipe helps equalize the exhaust pressures between the two banks of tubing as the hot gases and sound waves travel down the tubing. This, in effect, relieves the exhaust pressures as they travel through the H tubing, generally creating an increase in torque. This will also give an added sound reduction when the sound waves combine inside the H tubing.

X Pipe:

An X pipe will actually help to scavenge exhaust pulses from one bank as the opposite exhaust pulse passes through the X, thus creating a vacuum effect at the valve, resulting in a cleaner burn in the cylinder. This generally equals added torque and, like the H pipe, a reduction in sound as the sound waves combine in the X pipe.

le X fait meme chose que H mais en mieux sa aide et equilibre la sorti des gaz et en meme temp sa reduit son