What is bi-modal exhaust?
The Fusion is a bi-modal exhaust system, meaning it has two passages, or modes, that the exhaust can travel through the muffler. Each of the mufflers has two outlets, with one side having a butterfly type valve which allows the exhaust flow to be shut off, regulating which side of the muffler the flows exhaust. One side of the muffler is the "quiet" side, and one side is the "loud" side. The "quiet" side is a smaller, muffled and chambered tube, while the "loud"side is 3" tubing straight through.
How loud is it?
Through development and customer feedback they have shortened the muffler for 2008, making the "loud" side of the muffler "louder", which results in a tone similar to the famous Bullet system. In the closed position the tone would be slightly louder than the standard Route 66 system.
What controls the valves? The butterfly is controlled by a vacuum valve. BB Part Number FCOR-0235.