Exhaust Resonator

For a few years during the 1990’s and early 2000’s, it became a trend among teenagers and some auto buffs to remove their vehicle’s muffler and ride while making a great deal of noise. Do you remember hearing very loud cars zooming around parking lots, parks, clubs and other teenage hangouts? Then you remember the muffler removal craze. Nobody can say why a trend becomes a trend, but as far as trends going, removing mufflers from cars and trucks was quite a noisy one and one that we can gladly say good riddance, too. But what’s the story with mufflers anyway? How do they work and why on earth would anyone want to remove their muffler?

In the simplest definition of a muffler, a muffler is a piece of equipment that is designed to cancel out a car’s engine noise. The muffler looks like a small group of tubes with some holes in them. They may look simple, but they are actually as finely tuned as a piano or saxophone and that is how they work to cancel out engine noise.

Related to a muffler is an exhaust resonator. An exhaust resonator is used on sport compact cars and other racing cars to tone down the noise that those types of cars traditionally make. Like mufflers, exhaust resonators also use very complex and finely tuned technology in order to reduce potentially loud and obnoxious engine noise into a smooth, soothing hum.

Exhaust resonators look like mufflers, but can be made of durable glass. Some people describe exhaust resonators as mufflers that are designed to mellow out the tone of a car’s exhaust. Exhaust resonators are used in conjunction with a car’s catalytic converter and muffler. When used in conjunction with these other two auto parts, the exhaust resonator attempts to break up each of the sounds of your car’s combustions, and thus make the sounds of an engine less like a roar and more like a gentle humming sound.

Think of the exhaust resonator as a musical instrument. Say you simply put your lips together and blow out. What do you get? The classic “raspberry” sound. But say that instead of simply blowing out on your own, you put your lips together and blow into a tuned musical instrument, like a saxophone or a trumpet. Instead of getting that annoying and harsh “raspberry” sound, instead you get a pleasant tone. This same principal can be applied to the inner workings of the exhaust resonator.

To understand exhaust resonators, it helps if you understand a little more about sound. The basics are that sound is a wave, a pressure wave, that is formed from pulses of alternating low and high air pressure. The speed at which these pulses move through air is, of course, the speed of sound. Pulses in engines are made when the exhaust valve opens and lets out a burst of high-pressure gas, this in turn collides with the lower pressure molecules that were already present in the exhaust pipe. All those molecules then stack up together. The sounds end up making their way down the pipe and into the world. With no exhaust resonator this is a harsh and terrible sound. With the exhaust resonator present, the sound is transformed into that gentle, soothing tone we would rather hear when it come s to automobiles.

So you don’t mind a noisy automobile and would like to remove your muffler and eschew the exhaust resonator? To each his own. But remember that some counties or municipalities have noise ordinances and the loud, harsh sounds of a missing muffler or exhaust resonator could land you a ticket or, if you persist, a stint in lock up. Think about whether that’s really worth it before driving a loud, noisy car around the block a time or two.

There Are 2 Responses So Far. »

  1. Will I loose performance if I remove the resonator and install a high performance muffler like a Flowmaster? What I am trying to do is get more power and better gas mileage out of my vehicle. I have a 2006 Dodge Dakota with a 3.7 v6. Will it just be better to install just the performance muffler or a whole system with pipes insted of removing the resonator ?

    Thanks, Chris

  2. Ultimately the full exhaust route will in theory help with both the mileage and power rather than just replacing the resonator. You may also want to look at putting on a high flow air filter as well. You need to think of an engine as a large air pump, that being said the less you have in the way of pumping losses ie. restrictions in the intake and exhaust the more efficient the pump is, the more efficient the pump, the more power there is to run your vehicle and the less power it will require to do it, therefore getting better mileage too.
    Good luck!