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 exhaust flows. 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 we learned that customers love the bold, aggressive sound of the classic "Bullet" exhaust system for the C5 Corvette. The development team at Billy Boat Performance Exhaust has now taken all they learned from the development of the Z06 and C6 Corvette Fusion systems and applied it to the C5 Corvette. This system uses the basic design of the "Bullet" system with a bi-modal muffler, butterfly, and vacuum valve, which gives the driver a choice in the overall sound level. The loud side of the muffler has a tone similar to the famous Bullet system. In the closed position, the tone would be slightly louder than the standard Route 66 system. The development car was a C5 Z06 which had a highly modified engine (cams and cylinder head modifications), headers, and an off-road H pipe (no cats). This car was very loud with the standard Bullet system. The customer loved the sound and performance of the Bullet, but wanted an option to make the car a bit more "streetable". The team spent 4 months working with different mufflers and designs to achieve the classic "Bullet" sound in the open position, yet in the closed position the C5 Corvette Fusion Exhaust has a fantastic smooth tone and deep rumble. On the highway there is little or no noticeable drone in the cabin.
What controls the valves? The butterfly is controlled by a vacuum valve, which was built and developed completely in house. On the Z06 and the 2008 C6 Corvette with the NPP option, this valve is controlled by the ECU. The valve opens based on RPM and throttle position. Since the C5 Corvette has no option for the valve, we use the same vacuum kit and control as the C6 without NPP. The expertise at B&B is getting the "tone" right for your C5 Corvette, and we think they nailed this one. In the closed position, the tone is agresssive, but substantially quieter than the standard Bullet system. Open the valves, the overall volume and tone increases to the point of the classic Bullet exhaust tone.
What is in the kit? Billy Boat Performance Exhaust has spent months developing a stand-alone kit which allows any C5 Corvette to take advantage of the bi-modal system. The kit comes complete with all the wiring, control switch, vacuum line, vacuum accumulator, and vacuum switch needed for installation. The engine is the vacuum source and the installation is simple and straight forward.
Will they bolt up to my stock H pipe or my stock headers? Each part of the system will fit to a stock H-pipe or the stock headers. The parts can be mixed and matched (rear exhaust, x-pipe, and long tube headers). For best performance it is recommended to use the long tube headers, the Billy Boat x-pipe, and the Billy Boat C5 Corvette Fusion Exhaust. Billy Boat has combined the best of the Bullet exhaust with the best new technology to give you the Fusion System for your Corvette. The muffler tips are quad, double walled, 4" round or 4.5" oval. The mufflers and tips come completely polished and the result is a truly spectacular look combined with an aggressive sound will have heads turning everywhere you go. All B&B products are precision built in rugged fixtures, completely TIG welded, and are a direct replacement for stock exhaust components and include all hardware and gaskets. No machining, no cutting and no welding means easy installation. Each Billy Boat Performance Exhaust system is backed by a lifetime warranty against rust, corrosion or burn through and 2 full years against defects in materials or workmanship.