While there are hundreds of ways to modify a car for better performance, it’s the exhaust that brings the most bang for your buck, and not just in a literal sense. This is down to wider and straighter tubing to optimise airflow and combustion efficiency. To tame the sound of thumping cylinders, exhaust systems additionally use mufflers.
What are Car Mufflers?
Mufflers are sound-deadening devices installed along the exhaust piping. They consist of engineered inner tubes and chambers in varying designs to drone out the pressure waves created in each exhaust stroke, and what we as drivers interpret as sound.
There are different sound profiles in different exhaust mufflers. Some do a better job at cancelling out excessive noise, while others tune the sound for more driving pleasure. The good news is that exhaust systems are modular designs, and you can change any part you don’t like. including the muffler. This way you get sound worthy of the engine and the car.
The Anatomy of a Muffler
As mentioned, the design of the muffler determines the exhaust sound. Mufflers consist of several parts, with exhaust gases entering the inlet connecting it to the mid-section piping, a series of perforated tubes to disperse the sound waves and alternate the volume, a resonator that functions as an echo chamber to cancel out waves in different frequencies, and an outlet where the exhaust gases exit into the tailpipes and exhaust tips. In luxury cars where the end goal is a quiet exhaust note, there can also be a separate resonator chamber just before the muffler assembly.
The specific combination of the different parts, the use of various deadening technologies and materials and the design of the outer muffler walls lead to different types of mufflers.
Types of Car Mufflers
Mufflers come in three basic designs, each with pros and cons, and are intended for different types of cars and sound profiles:
- Straight-through/Glasspacks – these get their name from the straight perforated pipes wrapped in sound-deadening material, most often fibreglass. The design is both compact and performance-oriented in that it creates the least amount of backpressure. With no restrictions, exhaust velocity (or the speed with which the gases exit the car) and overall performance are higher, but so is the volume. These can get really loud, and go well with an equally brawny engine.
- Chambered mufflers – if you’re after a deep, throaty sound then look to a chambered muffler. This has a series of inner chambers of different lengths tasked to reflect sound waves against each other. How the exhaust sounds depends on the configuration and number of chambers, ranging from mellow to loud.
- Turbo mufflers – these have perforated tubes in an S-shaped design. As such they are more restrictive, meaning less power gains, but cancel out more of the sound waves. Some are additionally lined with sound-deadening material to keep things on the quiet side.
Choosing an Aftermarket Muffler – What to Look for
Compatibility and materials are the two main factors to consider after you’ve chosen which muffler will best suit the car in terms of the sound it makes. In short, the muffler needs to suit the exhaust piping. This means there are types with single inlets to accommodate single exhausts and dual inlets for twin pipes. Also, the muffler must be in the right diameter, so that inlets and outlets match up neatly with connecting tubes. And lastly, is there enough space to fit the muffler and secure it to the car with mounting hardware without any unwanted and lengthy mods? Manufacturers list all dimensions, so finding what fits is relatively simple.
Next, is choosing the material. Here buyers can choose exhaust mufflers consisting of aluminised steel or stainless steel. This is in the outer shell or muffler body. Aluminised steel is cheaper and performs quite well in handling exhaust gas pressure and high temperatures, has enough strength to resist minor impact, and is a decent choice in wet conditions. The downsides are that once the aluminised layer is gone, you’re left with a mild steel base, that can easily be punctured, and also suffers from advanced rust when coming into contact with water and road debris.
For a slightly higher price, stainless steel mufflers perform much better. They’re stronger, won’t kink or deform, and won’t collect rust, so they’ll also last longer and do a better job in different types of driving and road conditions.
Buying and Installation
Mufflers can be offered as integral parts of the different exhaust system designs (axle-back, DPF/GPF-back and header/turbo systems), or as separate units that can be installed to a stock exhaust or combined with different exhaust components. Most manufacturers have distinct lines of performance mufflers. Since all parts are of the bolt-on type, mixing and matching is possible, and lets you experiment with exhaust sound, and minimise restrictions.
Ensure that the muffler you get is supplied with the required gaskets and mounting hardware and get a professional fit to ensure you get the best results.