If you plan on upgrading your Mustang’s exhaust then you’ll definitely want to upgrade the mid-pipe. The mid-pipe is the section of exhaust piping that connects the exhaust manifolds or headers to the cat-back exhaust system. Getting rid of the restrictive factory mid-pipe will give you better flow in your Mustang exhaust system. This additional flow will unleash more horsepower and torque! There are different types of mid-pipes, but the most common with a dual exhaust system will be the X-pipe and the H-pipe.
There are plenty of differences between the mustang H pipe vs X pipe, but the most obvious difference is going to be the appearance. They get their name from the shape of the exhaust crossover pipes. One is shaped like a capital “H” and the other like the letter “X”.
The exhaust note produced by these two Mustang mid-pipes both provides a uniquely different exhaust tone. Deciding which mid-pipe is good for you will depend upon what type of sound you are looking for. Exhaust gas is scavenged differently with the two different designs resulting in the difference in sound.
The H-pipe intersects as an “H” and gives you the old school "American Muscle Car" sound that we have all grown to love! While this version of the crossover pipe produces a deep, throaty exhaust note, it isn't going to be as efficient at balancing exhaust gases as the X-pipe. The H-pipe is designed with two straight pipes and a crossover pipe that, while it does help to equalize exhaust pulses from the passenger side to the driver side, does not encourage more exhaust flow. The result is slightly more low-end torque but a little less high-end horsepower.
The H-pipe will still perform very well. They have been around for roughly 60 years and if they did not work, nobody would use them!
The piping of the X-pipe intersects in the shape of an “X” so that exhaust gases cross each other from each engine bank to create an increased flow that will help to evacuate the system efficiently and evenly. The X-pipe is going to create a more raspy tone and has a slightly higher pitch than an H-pipe with the colliding exhaust pluses. In most cases, you are going to see power gains in the higher RPM because of the smooth, continuous exhaust flow caused by crossing exhaust gases from the left side to the right side. The exhaust pulses are scavenged more efficiently producing that higher RPM power but they will have a slight loss in low-end torque.
The X-pipe, though producing a more raspy tone will have fewer decibels in comparison to the deeper exhaust note exiting the H-Pipe.
Removing your factory Mustang H-pipe and replacing it with an aftermarket, high-flow X-pipe will definitely add power over the stock exhaust! Dyno-testing has shown strong horsepower gains of 12-20 horsepower depending on supporting mods!
Decibel level tests show that the H-pipe will produce a deeper, louder exhaust note. Though this volume difference is not much, the actual sound of the exhaust can be noticeably different depending on the type of muffler that is added to the exhaust system.
Deciding on which mid-pipe you choose can have a big difference in the sound & performance of your Mustang. The best question you can ask yourself is "What am I going to be doing with my Mustang?". If your answer is hooning around with my friends on the weekends or tearing up the local drag strip. You might want to consider going with an off-road X or H-pipe. If you are looking for increased performance while still maintaining a tolerable tone that won't make your whole neighborhood hate you, go with the catted h-pipe or x-pipe. You'll enjoy whichever route you take, we can guarantee that!