Ducati is reportedly working on plans for a new exhaust system with electronically-controlled output pressure.
The report comes from Bennets in the UK, which unearthed some patent drawings of the new system. Bennets and other mags described the system as a “variable jet exhaust,” drawing comparison to a jet engine, but that’s not exactly accurate; while the system will allow riders to change the force (and possibly, the direction) of their exhaust output, like a jet engine does, it’s still meant for a standard motorcycle engine, with pistons.
The plans show an exhaust pipe incorporating a series of internal baffles which can be activated electronically to change the characteristics of exhaust output. It’s similar to a garden hose — pinch the hose, and the water output becomes more pressurized, increasing the velocity of the current. This system would allow the rider to increase the output pressure of exhaust.
Changing the exhaust output pressure would, in theory, allow the rider to alter its downforce on the motorcycle, and possibly allow Ducati to sidestep MotoGP’s ban on fairing “winglets.” The purpose of the winglets was to increase downforce, thereby avoiding the tendency of a motorcycle under power to wheelie, and creating more traction. Alas, just as the technology was getting interesting, the brains of the FIM and MotoGP got together and severely restricted its usage.
At the recent Sepang MotoGP test, Yamaha was seen incorporating aerodynamic aids to the inside of its factory MotoGP bikes, theoretically allowing the same advantages of winglets while keeping to the letter of the law, and avoiding having anything sticking out of the side of the bike. So, other teams are certainly thinking about ways to get around MotoGP’s restriction on aerodynamics; it would make sense to see Ducati doing the same.
However, it’s also possible Ducati doesn’t intend to use the system to alter the downforce on a bike, but to instead allow on-the-fly exhaust tuning.  Combined with electronic engine management and ride-by-wire throttle, this could allow the exhaust to deliver the needed resonance to optimally dispose of exhaust gases. Exhausts with in-flight tuning capability already exist, but their purpose is to simply change noise output. Ducati’s patented system could, theoretically, make the bike faster — or at least, make the engine run more efficiently.