Replacing the factory motorcycle exhaust system with a new after market system is a commonly used way to increase power and performance. A new exhaust system for a motorcycle may cost anywhere from $300 to well over $1000, depending on the manufacturer. The new exhaust system will increase speed and power in the bike, and will increase the sound of the motorcycle as well. This is beneficial, as it reduces the likelihood of a collision by making the motorcycle more noticeable to other motorists. The extent of the power increase will depend upon the bike itself and the type of new exhaust system that is being installed.