Your internal combustion engine does many interesting things. Most noticeably, it powers your car. To do this it needs fuel and air. When it has combusted the mixture, it needs to get rid of the byproduct – exhaust gas. These exhaust gasses are passed through the exhaust valves when they open, through exhaust pipes to a catalytic converter and then to the muffler. Once they have passed through the muffler, they head out into the atmosphere.
So why do you need a muffler? The exhaust gas would exit the car anyway, right?
Yeah sort of.
While the engine is running, it makes a fair bit of noise. Like if you heard the amount of noise you would say “wow, he wasn’t kidding, that’s loud.”
So that other road users or anyone within earshot of your car don’t say the same thing, you have a muffler or mufflers.
What is a muffler?
A muffler is made out of metal, usually steel or iron, sometimes stainless steel or even titanium in some cases. It needs to be made out of metal because exhaust gas is really hot. It is fitted near the back of the vehicle. Mainly because your engine likes a bit of distance between it and the muffler.
In order to muffle the sound of the engine’s running, the inside of a muffler is comprised of chambers and baffling. This makes the sound waves of the exhaust gas bounce around and become more muted and dispersed inside the muffler chamber/s.
There are a lot of different muffler designs to make the car sound better, quieter or a mixture of the two. Nice and quiet down low in the rev range and then rowdy up top. Your exhaust flow is dependent on how restrictive the muffler is. The quieter the car, the more restrictive the muffler and vice versa.
What does a muffler do?
We kind of covered that above. It muffles the sound waves produced by your engine as it operates.
The baffling inside the muffler is wavy and designed to absorb noise. It works like insulation, if you’ve ever seen sound insulation you’ll get it. The exhaust gas must pass through the muffler as it is forced through the tubing by the piston and exhaust valve opening.
Your muffler also makes sure that the sound waves are controlled based on required flow. They will allow the car to ‘breathe’ as it should, without droning. Droning is where at a certain rpm your exhaust gas sound waves are produced in a way that makes one continuous, very annoying note.
The muffler being restrictive creates some back pressure in the exhaust system. That might sound bad but automakers design the timing and mixture based on this simple fact. The backpressure can make your car more efficient and sometimes more powerful.
The muffler reduces engine noise. We’ve covered that extensively now. It is also legally required by the Government. A loud exhaust sounds cool when it’s properly designed. If it’s a DIwhY exhaust, it sounds terrible. Sound emission is legally required because if it’s too loud then it can be seen as a social nuisance.
What are the different kinds of mufflers?
There are a bunch of different muffler designs. There are also a few people who cut their mufflers off and drive around ‘straight piped’.
Straight piped cars are indicative of the people who drive them. Very loud, very obnoxious, and very stupid.
Your best bet is your stock muffler, if you want a bit more noise go with a manufacturer who tests and designs mufflers for your car.
What to do if there’s a problem with my muffler
We can easily set you up with a skilled partner garage to take care of it. Whether your muffler has rusted and sounds bad, been damaged, or you have a query, we can handle it.
Your muffler is required to be in good working order for your warrant of fitness. If your muffler or exhaust needs work, we can get it done easily and cheaply.