Your vehicle’s muffler performs an important task. By conducting exhaust gasses through a series of baffles and chambers, it reduces the harsh noise produced by your engine. This results in a quieter driving experience for you and for the people within earshot of your vehicle. Removing your OE muffler and replacing it with a performance unit can dramatically alter the sound your vehicle produces and help increase horsepower. In our guide to performance mufflers, we’ll review which materials are used to construct these aftermarket components, the most common muffler designs, and how to choose the right size muffler to fit your exhaust system.
The most common materials used to construct mufflers are aluminum, aluminized steel, and stainless steel. The characteristics of these materials are explained below.
Aluminized steel is an affordable and durable exhaust material
Aluminized steel is created by coating regular carbon steel with an aluminum-silicon alloy. This coating acts as a protective layer against corrosive elements, making aluminized steel a low-cost alternative to stainless steel. Many original equipment mufflers are constructed using this affordable material.
Stainless steel offers the ultimate corrosion resistance for exhaust systems
Stainless steel is an alloy created through combination of steel, nickel, and chromium. This material combines a polished chrome-like appearance with excellent corrosion resistance and durability. While it usually carries a higher price than its aluminized counterpart, stainless steel’s superior rust resistance and strength makes it well worth the investment.
Aluminum isn’t commonly used for constructing exhaust components due to its tendency to deform under high temperatures. Despite this, some companies do offer aluminum mufflers which are popular among some race enthusiasts due to their light weight.
Most mufflers share a similar external appearance; they feature inlet and outlet tubes attached to the ends of a metal shell. To understand the difference between various muffler designs, it’s important to understand what’s going on inside the muffler itself.
A chambered muffler
This muffler design is named for its series of internal chambers which help temper the sound of your exhaust. The chambers accomplish this by using angled baffles to deflect sound waves into one another. These chambers and baffles can be configured in a number of ways, allowing muffler manufacturers to tune the muffler for a variety of noise levels, from a subtle rumble to a thunderous roar.
A flow-through muffler. Note the transparency exposing the inner tubes
Sometimes called a straight-through muffler, the flow-through design does away with chambers and baffles, allowing exhaust gasses to flow freely from the inlet to the outlet. The body of the muffler is sometimes filled with an insulating material surrounding the inner flow-through tube. This free-flowing design reduces pressure in the exhaust system, which leads to small horsepower gains and a very aggressive exhaust tone.
A glasspack muffler
This design eschews the large oval body of chambered and flow-through mufflers for a round, narrow body. A glasspack muffler is named for the fiberglass or steel wool insulation used between the internal tube and external housing. Glasspacks do little to deaden the sound of your engine’s exhaust, but they do temper harsh exhaust tones. For this reason, a glasspack might more accurately be referred to as a resonator. For the loudest and most aggressive exhaust tone possible, a glasspack is the way to go.
Sizes and Configurations
In some cases, selecting a muffler to fit your vehicle isn’t as simple as inputting your year, make, and model. It requires knowledge of your exhaust system specifications. When choosing a muffler the following measurements and configurations are important to take into consideration in order to ensure proper fitment.
Body length, width, and height:
These measurements are taken without including the inlet or outlet tubes on the muffler.
Inlet and outlet configuration:
The arrangement of the inlet and outlet tubes on a muffler are separated into the following categories.
Inlet and outlet diameter:
Centered: Inlet and outlet tubes are located in the center of the muffler body.
Offset: One tube is centered, while the other is located on either the left or right-hand side of the muffler body.
Offset (opposite sides): The inlet and outlet tubes are located on opposite ends and opposite sides of the muffler body.
Offset (same side): The inlet and outlet tubes are located on opposite ends of the same side of the muffler body.
The diameter of the muffler’s inlet and outlet tubes needs to be compatible with the rest of your exhaust system to fit correctly. The best way to measure your exhaust system’s diameter is by using a digital caliper to gauge the inner diameter of your exhaust tubes.