How to Make an E46 M3 Louder
- 1). Install a more free-flowing muffler. The stock M3 muffler is designed to muffle the sound of the engine rather than let it be heard. Installing a stainless steel muffler from a company like Magnaflow will deepen the exhaust note and make it louder. Installing a muffler on a high-end car like the M3 requires special tools. This job should be left to a professional muffler shop.
- 2). Replace the stock exhaust with a full-performance exhaust. This takes the free-flowing muffler method to the next level. Replacing the stock exhaust system with a larger diameter exhaust (made of stainless steel if you prefer) will unleash the M3's engine note. You also will gain a noticeable amount of horsepower with this modification. You can install a performance catalytic converter for even more sound and performance. Like the muffler installation, this modification should be performed by a professional familiar with modifying M3s.
- 3). Install aftermarket headers. A set of tuned headers in place of the stock M3 manifolds makes a big difference in sound as well as power. Tubular headers feature thinner wall construction as well as larger and smoother internal wall surface for optimal breathing and performance. If you combine headers with a larger diameter exhaust, your M3 will probably sound more like a race car than a street car.
- 4). Install a cold air intake (CAI). The stock M3 air box is relatively restrictive. A cold air intake features a larger air filter and more free-flowing tubing. Though the primary advantage of a CAI is added performance from the addition of dense, cold air to the motor, a CAI will deepen the intake sound of the engine as it inhales more air. Installing a CAI requires removing the stock air box and installing the CAI in its place.