I drive a turbocharged mazda mx-5. At highway speeds, the engine is turning nearly 4000 rpms and is quite droning. Is there anyway to construct an exhaust system that both flows better and lowers decibels?
improved flow through, quieter: NO (in a performance set up those are mutually exclusive terms). and i would most highly recommend against further baffling/or any increased restriction of your exhaust (improved flow through is a positive-restricted flow through is a negative).
Add the biggest resonator you can fit on your car
Oh it's possible but the more you drown out the sound in theory the more you are affecting your performance. Performance exhausts are louder due to the fact that they lower your back pressure and help your exhaust gases flow better. You could install a baffle/silencer in your tip/can depending on what you have. You can make one or possibly buy one. It is basically a cone that will restrict the gases to such a diameter and length which will keep your car quieter. There will be a minor affect to your performance but most people wouldn't even notice this.
