The new 2012 Mustang Boss 302 features a unique Quad exhaust system never before seen in a production Mustang that exudes an unmistakable exhaust note. When building the quad exhaust system Ford engineers had to consider three variables: legal noise restrictions; backpressure, and ground clearance. With a free flowing exhaust already in place on a base 2011 Mustang GT, engineers quickly realized backpressure would not be an issue and as a result tuning the exhaust for a Boss specific sound would not be hard at all.
The quad exhaust system features four exit points, two at the rear of the vehicle and two on either side of the vehicle just ahead of the rear wheel opening. The exhaust flows from the headers down through an exhaust crossover where they split off in the two directions. The exhaust that is sent to either side of the vehicle goes through a set of metal discs that act as tuning elements before they exit the side. In all honesty the side pipes do not flow that much exhaust but they do provide substantial exhaust sound. The less restricted exhaust continues on to the rear of the vehicle where it exits.
“We added the attenuation discs to meet legal regulations, but we knew buyers might operate these cars in situations where noise regulations weren’t an issue,” Carney said. “The disc is removable and includes a spacer plate sized to match aftermarket exhaust dump valves. If an owner wants to add a set of electric valves, they just undo two bolts on either side; the disc and spacer slide out and the valve will slide right in. And the side pipes are tuned so that drivers can run wide-open and the sound levels are comfortable – very aggressive but livable for an all-day track outing.”
Source: Ford Motor Company