It didn't take much, some pictures and an article published on the site
Bennets.co.uk 3 days ago, so that the rumor ignited the web and confusion spread: The Ducati would use a variable geometry exhaust at Sepang, to compensate for the support lost with the ailerons! It's wrong.
The principle put forward in the patent is to detect the takeoff of the front wheel and, at this moment, to reduce the diameter of the exhaust by movable vanes to create a thrust similar to that of a jet plane, which, from suddenly, and depending on its inclination, would press on the front axle, thus compensating for the loss of the ailerons.
The point (an anti-wheeling effect) is explicitly developed with strong text and drawings from a patent filed by Ducati this month, and which we found…
"A motorcycle (1) comprising a frame (2) with which an internal combustion engine (3) is associated, from said internal combustion engine at least one exhaust pot (6) of burned gases leaves, the pot of exhaust having an open end portion, said frame (2) being mounted on a front wheel (4) and a rear wheel (5), a control board or control unit (10) being included, for controlling the torque produced by the engine (3) and other parameters such as vehicle speed and position in space relative to the road surface, the motorcycle (1) comprising a system capable of checking when the front wheel (4) of the motorcycle detaches from the road surface during acceleration. The system comprises narrowing means (36) for reducing the section of the exhaust gas outlet zone of the exhaust pot (6), during said reduction, the reduction being obtained as a function of the torque produced by the engine ( 3) and the position of the front wheel (4) relative to the road surface. »
At this point, it is useful to cling to a few quantified facts.
The force produced by a motorcycle exhaust (the thrust, on an airplane) is relatively weak even if it manages to raise our hair when we pass behind it. However, only a tiny component of this force would be applied to the front axle.
Remember that the calculations that we published in a GP Racing article estimated the support of the Ducati fins at nearly 40 kilos (unsuitable unit of measurement but more meaningful than daN).
An exhaust, even if it has a variable and reduced diameter, is far from being able to support 40 kilos. The advantage provided would probably not be 10, nor even 5, nor perhaps even a single kilo, i.e. the support generated by a counter-rotating engine during acceleration. All at the cost of a system managed by complex equipment, which could fall under the ax of regulation at any moment.
We would therefore really like to believe in the effectiveness of this solution, especially since blown exhausts have made their way into F1; it would be fantastic and worthy of the inventiveness of Italian engineers! But we admit to being a little skeptical about the real effectiveness of the system, given its complexity in relation to the effect produced. That doesn't mean it won't work, and the very explicit patent proves it!
We also remember that everyone made fun of Ducati when they brought the wings up to date. And we know the rest!
A kilo of support here, a kilo there, and it can make the small difference that allows you to win a race at the finish...
It is therefore urgent to wait, if only to see if all these hypotheses are confirmed and tested (because this was obviously not the case at Sepang today), and possibly adopted in racing.
Asked by Peter McLaren from the Crash.net site on what is in the box next to the exhaust, Michele Pirro replied in a humorous way: “a hot dog, in case I’m hungry”.
