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Aftermarket Wrangler Mufflers & How They Work

Written By: Louis Orellana

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Mufflers can be a hassle; they're large and cumbersome, and they tend to be one of the first contact points when rock crawling. Swapping out your Wrangler's muffler can net high ground clearance as well as open up your rig's vocal chords.

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There’s no doubt the aftermarket world for Wranglers is vast and encompasses most components on the Jeep. Some upgrades serve a stylistic purpose, and some serve a functional purpose. Occasionally, there are aftermarket parts that serve both. Exhaust mufflers are categorized within that scope. In this information guide, we’ll discuss what a muffler does, the differences between a factory muffler and aftermarket muffler, the variety of aftermarket muffler options that are available, some of the differences in design and overall functional differences.

How Does a Muffler Work? What's the Difference Between Stock and Aftermarket?

A muffler is primarily designed to reduce the sound of the engine’s exhaust system. Most factory mufflers have a series of tubes with small holes that fall in-line within chambers or baffles. These holes and chambers help relieve some of the sound pressure coming in through the exhaust and redirect the gases through the exit pipe.

An aftermarket muffler with a straight-through design typically features a perforated pipe that has a wool type of material wrapped around it, followed by a fiberglass packing and aluminum protective outer casing. In a straight-through design, the exhaust gases enter the muffler, exit through the holes of the perforated tube. The fiberglass packing material absorbs the sound vibrations, producing heat which is then disbursed the through the aluminum outer shell.

Newer straight-through mufflers utilize angled chambers to help with the sound and overall efficiency. The angled chambers consist of precisely placed plates that redirect the exhaust gases and sound energy, without the excessive buildup of heat and with less overall restriction. The angled plates also create a scattering effect that produces pressure, which accelerates the flow of exhaust gases, allowing it to exit through the tailpipe at a quieter and faster rate. The spacing of the chambers and angle of the plates all play a primary role in the overall unique exhaust sound.

Types of Mufflers & Cat-Back Exhausts

A muffler can be incorporated within a complete exhaust system replacement from the catalytic converter back, or it can be a stand-alone replacement from the axle back. Generally, all aftermarket exhaust and muffler solutions will still provide a slight increase in horsepower and torque, while also giving the system an overall deeper exhaust note. The differences in muffler construction and design can produce a large range in exhaust note and volume. These are among the most common options available for JK Wranglers.

Cat-Back exhaust system: Within a cat-back system, the full exhaust is replaced from the catalytic converters back. When this is done, typically the muffler size is significantly reduced or sometimes re-positioned. Primarily, this provides the Jeep with more ground clearance, especially during ascending and descending maneuvers. It also increases the overall sound of the exhaust.

Systems like the Magnaflow Rock Crawler are uniquely designed with ground clearance in mind. This system relocates the muffler to a mid-pipe location, further up on the exhaust, and it also drastically reduces the overall size of the muffler. This eliminates the large bulky and heavy factory muffler and positions it in an area that allows it to be neatly tucked in and away from possible damage from the terrain when off-roading. In addition, the system takes a more straight-through approach, with fewer bends, which provides an increase in horsepower and torque. The smaller mid-pipe muffler design also offers a distinct exhaust note that isn’t overpowering or droning inside the cabin of the Jeep.

VIDEO: Review & Install of Magnaflow Rock Crawler on a JL

Magnaflow’s Performance Series system is a cat-back exhaust that takes it up a notch and is more similar to the factory exhaust, but with significant adjustments. The Performance Series offers a smaller muffler, but unlike the factory muffler that has only one exhaust tip, this system offers a dual-tip muffler. The dual-tip design doesn’t improve performance and is purely a stylistic upgrade over the stock muffler. It’s important to note dual-tip mufflers typically hang slightly lower in order to properly expose the polished tips. This results in less ground clearance and increases the potential of contact with terrain during some ascending and descending maneuvers. The system still offers an overall improvement in performance, especially on low-end torque, while still providing an improvement in sound.

The Borla Touring cat-back exhaust system seems to offer the best level of compromise between performance, clearance, and stylistic design. Borla has been known for exhaust quality within the aftermarket space. The system comes with a “Million Mile” warranty that essentially covers the system for the life of your Jeep. The system features a simplistic design that mimics the factory exhaust with a mid-pipe and rear muffler layout, but greatly reduces the overall size of the rear muffler. This allows the system to tuck in higher in the rear and increase overall ground clearance when off-roading. In addition, the system comes with a single highly polished exhaust tip that improves the overall styling of the Jeep’s exhaust, without compromising the benefits of ground clearance. Rounding off the benefits of the Borla system is their unique exhaust note, which gives the Jeep a deep throaty sound. 

Axle-Back Exhaust Systems

These kits are generally much less expensive than a complete cat-back exhaust kit. The main reason is because it utilizes the factory exhaust from the cat-back up until the Jeep’s axle. From there the factory exhaust piping leads into what’s called an axle-back system, which mainly consists of a new muffler that can vary in size, along with a variety of exhaust tips. These are some options available for axle-back exhaust systems.

The MBRP Installer Series is a sleek minimal axle-back muffler design. It features dual exhaust tips that give the Jeep a nice balanced look from the rear. The smaller muffler is angled slightly up to help tuck it into the rear of the Jeep and assist with better ground clearance. The exhaust tips, however, hang low and could still provide a contact point during extreme articulation or ascending and descending maneuvers. MBRP offers the same system in a black finish for a more stealthy overall look, if you’re looking to head in that direction. MBRP exhausts are known to offer a rich mellow exhaust note that isn’t overpowering or droning within the cabin. In addition, the clean mandrel bent design provides 22% improvement in overall exhaust flow, which results in a noticeable improvement in horsepower and low-end torque.

If your focus is more on price and ground clearance, the AFE Scorpion Hi-Tuck axle-back exhaust might be a better solution. This muffler is significantly smaller than the factory muffler and retains the single exhaust tip design, which allows it to increase overall ground clearance as much as possible from the rear of the Jeep. In addition, the minimal design is very clean and simple. The system comes in a raw unpolished finish, which helps maintain the overall price considerable low, without comprising on quality or performance. The bolt-on installation makes this axle-back exhaust a great entry point replacement for the factory muffler. 

The Corsa Dual axle-back exhaust rearranges the muffler angle and provides a nice overall compact design. The system also offers a single exhaust outlet that is then split into a dual tip design. This gives the Jeep a distinctly sporty look, without the compromise in ground clearance. In addition, the free-flowing straight through muffler design offers a slight increase in horsepower and torque. Cora’s proprietary Reflective Sound Cancellation (RSC) technology gives the exhaust an aggressive exhaust note without cabin drone or vibration, which is critical on long highway drives.

Conclusion

As we’ve showcased in this information guide, there is a large variety of exhaust and muffler options to choose from for your Jeep. Your particular need and ​stylistic goals will help determine which system is right for you. Thankfully, most exhaust systems are fairly priced and easy to install, making this modification an easy choice for your Wrangler’s overall performance and look.

Fitment includes: 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, JL, JK, TJ, YJ, Laredo, Sport, Islander, S, Sahara, Renegade, SE, X, Rubicon, Unlimited, Sport-S