Customizing your exhaust system from headers to tailpipe ensures you get the sound and performance you're looking for. One of the most important exhaust pieces you'll need to decide on is the mid-pipe.

What Is a Mid-Pipe?

The mid-pipe is the section of exhaust that runs between the muffler and the catalytic converter. Some mid-pipes will have the catalytic converter built in. When you’re upgrading the rest of your exhaust, you’ll need to decide what type of mid-pipe will fit your build.

Do You Even Need a Mid-Pipe?

As your engine runs, the cylinders fire at different times. This creates waves of pulsating exhaust. A mid-pipe equalizes your exhaust, creating a more consistent flow.

You can have an exhaust without a mid-pipe. But considering they offer performance and sound benefits, most people opt to have one.

The two most popular types of mid-pipe are h-pipes and x-pipes. Check out this video for an overview of the differences between them.

TYPES OF MID-PIPES

Mid-pipes come in several styles. Whether your vehicle is single or dual exhaust will inform what exhaust pipe choices you have. While all single exhaust systems are Y-pipes, dual exhaust systems have a couple options.

Y-Pipes

If you have a single-exit exhaust, then you have a Y-pipe.

Y-pipes take two exhaust streams from the manifolds and join them together. Then as a single pipe, the gas travels through the muffler and exits through one tailpipe.

The obvious con of this system is that it’s restrictive due to the single pipe.

If you like having a single exhaust but want a less restrictive option, there are aftermarket Y-pipes. By increasing the diameter of the exhaust, these can improve your overall flow. Some of these Y-pipes also eliminate the resonator for a noticeable sound improvement. Eliminating the resonator also reduces your total weight, another benefit.

• Restrictive
• Single exhaust system
• Can eliminate resonator for better sound

H-Pipes

H-pipes take two pipes coming from the manifold and connect them with a small pipe, making an “H” shape. This design creates a deep muscle-car exhaust note and low-end torque.

H-pipes are able to offer more low-end torque by creating some backpressure. While generally you want to reduce backpressure to free up horsepower, a small amount can actually improve low-end torque.

• Deep, throaty exhaust sound
• Slightly less free-flowing than an X-pipe
• Small increase in low-end torque

X-Pipes

X-pipes are the freest flowing option for a mid-pipe. Instead of having a crossbar, like the H-pipe, the X-pipe takes two pipes and crosses them over. Sometimes X-pipes are called crossover pipes for this reason.

Ultimately, this means the X-pipe is the option that makes the most sense if you’re at the top of the power band.

• High-pitched, raspy exhaust sound
• Slightly more power at top of power band
• Freest flowing mid-pipe style

“True Dual Exhaust”

A very rare setup is a “true dual exhaust” or “divorced duals.” While most mid-pipes intersect to equalize exhaust gases, a true dual setup runs straight to the tailpipe with no intersection. Both pipes have their own respective mufflers and tailpipes.

It might seem like this would be the best and freest flowing exhaust form. But X-pipes and H-pipes both benefit from a slight Venturi effect which helps pull exhaust. A true dual exhaust doesn’t produce the Venturi effect.

Many V6 owners have pointed out that this difference in performance is very slight though. Meaning the true reason to get a mid-pipe for them has been modifying their exhaust sound.

H-Pipe vs X-Pipe

For most people, the debate about which mid-pipe is right for them comes down to X- vs H-pipes. Both of these mid-pipes provide a way to equalize exhaust gases and create a smooth flow.

X-pipes have a slight advantage for drivers who are mostly concerned with top speed and efficiency at high RPM. H-pipes have a slight advantage for launches thanks to better low-end torque.

What does a midpipe do?

Midpipes are stainless steel exhaust pipes that run from the beginning of your exhaust system to the muffler. They equalize the exhaust coming from the set of headers and help cars release sounds and fumes, which allow vehicles to be environmentally friendly.

Aftermarket midpipes are equipped with a right-angled connecting tube or multiple attached pipes. The reason for this is to balance the pressure in your exhaust system, responsible for high-performance.

As cylinders fire, exhaust fumes are forced through the headers to the front of the exhaust system at different intervals. The midpipe equalizes this mashup of fumes before pushing them through the rest of the exhaust system.

Where is the midpipe located?

Midpipes are usually found between the headers and exhaust muffler. The muffler mounts to the midpipe, which, as we explained above, carries sound and fumes from one part of the exhaust system to another–usually in an organized bundle or system. Upgrading midpipes simultaneously as your muffler will often result in better performance, as most aftermarket midpipes have a larger diameter and are more durable than just-good-enough stock pipes.

Midpipe vs. Downpipe

When you look at the middle section of the exhaust system, you will notice two pipes: one on top (the downpipe) and one below (the midpipe). The purpose of both is the same: release fumes and noise as sparingly as possible. The downpipe and midpipe are similar-functioning components, except a downpipe is usually referenced when you have a turbo. The downpipe attaches to your exhaust system at the front, while a midpipe extends from towards its end between catalytic converters or mufflers.

Does a Midpipe Add Horsepower?

Yes–though slight. If you're looking to upgrade your car’s sound, an aftermarket midpipe is the way to go. However, you shouldn’t expect a high amount of horsepower from this kind of mod. Aftermarket pipes are usually wider than stock pipes, so you’ll gain more horsepower, but not a serious amount. With performance driving, even the slightest increase in power could earn you a trip to the winner’s circle. And getting a larger diameter midpipe opens up the fume pathways so your car can breathe a little better–instantly adding more functionality.

Does an Aftermarket Midpipe Make Your Car Louder?

Yes. Wide-diameter midpipes will make a vehicle's exhaust system more efficient and free-flowing, increasing its noise output. It does depend on which midpipe you install, though. A midpipe with just a resonator and no catalytic converter would pump sound like mad.

There are two different kinds of midpipes with different flow patterns and pipe configurations: labeled H and X, respectively. The H-style pipe and the X-style pipe both have a different appearance, noise, and tone outputs. Keep reading so you can complement the sound of your car by choosing the right exhaust system.

X-style pipe

If you're looking for that high-pitched tone, some distortion, and more power at higher speeds (higher RPMs), then an X-pipe is an excellent choice. The X-tube pipe gets its name from the vertical connecting tube merging in the shape of the letter X.

H-style pipe

H-pipes have an aggressive, deep rumbling noise, like what you'd hear in a muscle car. Offering more torque at lower speeds than X-tube products, H-tube pipes are a type of curved perpendicular connecting pipe that creates the letter H.

Which midpipe is best?

You should take into consideration what components are in your vehicle currently, and what mods or upgrades might be on your list before making any decisions about which midpipes will work best. There are a lot of different parts that you can upgrade your car with and many mods or upgrades available.

But really, the ultimate question when deciding between an X-style exhaust pipe and H-pipes? The sound. Remember that X-tubes are high-pitched and H-tubes are low and rumbling.

So if you want more pressure, more speed at higher RPMs, and beautiful high-pitched tones, you should invest in an X-tube. But if you want more power/torque at lower speeds and growly tones, an H-tube is the right choice.

MID-PIPES AND HEADERS

While mid-pipes usually attach to the exhaust manifold, if you’re planning a serious exhaust overhaul you may also be considering headers. If that’s the case, it’s important to make sure your headers and mid-pipe are compatible.

If you’re interested in long-tube headers, then your mid-pipe will almost certainly need to be the same brand. If you want to mix brands, you’ll need to research compatibility a lot more. While there are some good reasons to mix brands, usually it’s best to go with the same one for the best fit.