Loud and proud: The right way to go about modding a car's exhaust

One of the first modifications a budding car enthusiast does to his ride is changing the muffler or exhaust. Not only does a well-designed exhaust provide better performance, but it also changes the note of a car’s exhaust, making it sound roughty, enhancing the overall appeal of the car. Some say the latter is the point in the first place.

Anything for pogi points, right?

But is it legal?

In many countries, the legalities of changing an exhaust depend greatly on what is being changed. Part of that is due to noise, and part is due to environmental regulations.

Here's what you should remember

To start with, all new cars are fitted as standard with catalytic converters. These react with the hydrocarbons in the exhaust that don’t get combusted, and they are catalyzed into less toxic particles that can be exhausted into the air. They can sometimes be highly restrictive and, more often than not, cannot be removed to meet emission regulations.

So if you’re planning to change your exhaust, the best you can do if the catalytic converter is required is to do a cat-back system or an aftermarket exhaust system that changes what is after the catalytic converter.

Next up is noise. Of course, if you live in a gated subdivision or a highly residential area, there will inevitably be noise caps placed on vehicles. In the case of the Philippines, the Land Transportation Office has placed the limit at 99 decibels, measured during registration renewal at engine speeds between 2000 and 2500 revolutions per minute. If you were to replace your exhaust, make sure it stays under that 99 dB number.

Lastly, it must, of course, be safe. It can’t simply be dangling from one side or the other, contacting the road, or bouncing up and down whenever you go on bumpy roads. It has to be safely secured to the undercarriage of the vehicle, likely by exhaust hangers that hook into place underneath the car. This requires it to be designed specifically for your car so that it fits in the right places. 

Stick to the rules regarding exhausts, and there should be no reason for them or your vehicle to be illegal. If a traffic enforcer insists your exhaust is too loud, simply ask if they can enforce such a law at the moment - with a decibel-o-meter.