Growing up a car nut, I believe this topic is second only to the check engine light when it comes to misconceptions. When you ask a person about exhaust systems, they’ll probably mention words like headers, resonator, mufflers, etc.
So, I’ll walk you through what a complete exhaust system really is or what it exactly does for your vehicle.
A header bolts on to the cylinder head of the engine. There have been several types of header designs produced in the market the last 30 or so years. There’s a 4:2:1 type, which has four pipes connected to two pipes which are in turn connected to another pipe that leads to the catalytic converter, a 4:1 type where in 4 pipes connect to just one instead of having them pass through two more pipes, and a 1:1 type where in the catalytic converter is built close to the cylinder head.
The main reason for the evolution of the headers to the 1:1 type is that it’s a more cost-efficient design using less piping without sacrificing airflow. Exhaust headers are some of the easiest bolt-on modifications you can make. Headers make it easier for your engine to push exhaust gases out of the cylinder while your vehicle’s engine produces all its power during the power stroke.
The resonator is also known as a silencer, “scav” or a scavenger pipe. Its one and only job is to make the whole exhaust system quieter. It does not create power or result in power loss when retained or taken off. If you want your car to make more noise (and you’ll make more enemies, too – Ed), go for a straight pipe.
The muffler helps reduce the amount of noise produced by your engine while controlling its back pressure, leading to improved endurance and performance. This is what confuses a lot of people. Contrary to what a lot of people think, a muffler does not increase your vehicle’s sound. By definition, it muffles the sound or diminishes its volume.
The bigger the muffler, the quieter the car gets. There are misconceptions out there that when you put on a muffler, you get more noise. It’s just that you get more noise when you fit a smaller one to your vehicle.
There are several types of mufflers available in the market. A chambered muffler, usually the muffler produced for stock cars, has three separate chambers. Two pipes divided by the muffler from the resonator to the tail end of the vehicle do not meet. The whole point of the separation is to create more muffling for the sound. A free-flow muffler is a more performance-based choice for the car enthusiast. More airflow to the end of the exhaust system is allowed, leading to a noisier engine sound. The easiest way to tell if you have a free-flow muffler is by looking at it. You can follow it from end to end. There are no chambers, no restrictions whatsoever.
So, does a free-flow muffler produce more power compared to a chambered one? Absolutely.