Opening
Cocorico, a new French invention, may soon improve the efficiency of our engines while reducing pollution and consumption. A real breakthrough technology for which high-level competition (GP or Endurance) will be an excellent playground. While waiting to get to this point, lerepairedesmotards.com is introducing the APAV Adapter!
Romain Besret, a self-taught engineer, has its origins in this patented invention, which is the subject of many lusts. It must be said that it revolutionizes the management of "compression ignition" (gasoline) engines, which, unlike "compression ignition" engines (diesel ...), must operate at constant richness and actually use the throttle valve. Indeed, as a reminder, on a gasoline engine, power is controlled by choking the intake to reduce intake air flow. In addition, the amount of fuel injected is adjusted simultaneously for an optimal air / gasoline ratio. On diesel fuel, the intake is always fully open (no butterfly box), and the power is regulated by injecting more or less fuel.
Current state
Today, four accepted load management systems coexist. The most classic is the butterfly valve, found on 99,9% of motorcycles. However, it has three drawbacks. First, an obstacle is placed in the duct to control the air flow at the low openings of the handle, which creates enormous pressure losses and colossal aerodynamic turbulence. This obstruction also counteracts waveform feedback and other acoustic chords from the engine if the duct is partially blocked. The wave no longer reaches the end of the channel as it hits the butterfly. Thus, variable length intake systems fail or are small and at least perform poorly on small handle openings. Second, the petrol injector tends to be poorly positioned as it waters the duct rather than reaching directly to the valve. This "wetting" of the duct is detrimental to injection response times, consumption and pollution, especially cold. Indeed, some of the gasoline that remains on the intake wall is not absorbed by the engine when it needs it. On the other hand, when the pilot turns off the throttle because he no longer needs power or fuel, so a very strong depression of the "siphons" propels him and sucks in the remaining drops of gasoline in net losses. Using shower nozzles placed in an air box prevents the walls from getting wet, however, using gasoline mist is certainly good for performance, but not for consumption. In addition, since the injector is located behind the butterfly, very far from the valve, the response to partial load changes at idle is not accurate, and in fact, the shower injector is almost systematically supported by a conventional injector located "across" next to the valve. As a bonus, it costs two injectors per cylinder and control that comes with… tertio, once the throttle is large, the throttle always stays in the middle of the flow, which still disrupts the flow at full load, causing very little loss of maximum power. Not a glop.
Guillotine!
No, this is not what the butterfly deserves, it is a process comparable to the flat bushels of our ancient carburetors. It only solves one problem, the full load problem, as it completely cleans the duct. Better for maximum power, but let's relativize this gain, keeping in mind that even on a lap, we are finally in short order, especially if the bike is very powerful! On a GP motorcycle, we are no more than 35% of the time at full open on the fast track. For reference, in the 1990s, 500 GP was only about 10% of the time on the Jerez circuit!
Rotating bushel.
Unusually this device is used by KTM on motorcycles3. It offers the same advantages as the duct profile guillotine, slightly less poor at partial loads. But for the rest ... This is a white and white hat with the two previous solutions.
Distribution of variables
The last process, not found on motorcycles today, is to remove the throttle valve or any other similar system and control airflow or 100% variable allocation, which modifies valve lift and valve opening times to match the power requirements expressed by the driver. When idling, the valves open at a very low height and within a very short time. When fully loaded, they take longer to stand up and therefore take longer. The control of this 100% variable distribution pattern can be electro-hydraulic, hydro-mechanical, or even 100% electric. The problem is that these systems increase proliferation and / or are not very fond of high modes, which is synonymous with significant effort. In short, at the time of the titanium valves on our motorcycle engines, this type of variable distribution is not yet in motion ... NB, This type of variable distribution is different from the VTEC Honda, DVT Ducati or VVT Kawasaki.
What APAV offers
The principle is to control the passage section of the duct by approaching or moving the airfoil away from the intake pipe. To be more scenic, we could talk about an egg or a drop of water. The further from the airfoil, the larger the section, the closer it is, the more gases are closed. The first advantage is that at very low loads (slowing down and small holes), instead of disturbing the flow, it is directed peripherally overspeed to the edge of the duct. Since the injector is implanted at the end of the airfoil, it sprays battery fuel onto the axis of the air duct and nothing is deposited on the walls. Thus, consumption and pollution are reduced. At medium loads, the profile recedes and the duct becomes more defined, which allows good control of the acoustic effects that favor filling. At full load, the airfoil completely clears the airway inlet, but its far presence contributes to the overspeed of the throttle valve at the entrance to the cone, while further the airway is completely smooth. The result is a very clear improvement in engine fill, evidenced by a double-digit percentage increase in horsepower or even two dozen !!! The system has indeed been successfully tested on a bench on a 4-stroke single-cylinder engine with a volume of 250 cm3 ...
Butterfly Effect.
Introduced to various players in motorcycles and cars, APAV has always hit the head with a nail, and no one has said that its principle does not matter. We are not a secret of the gods, but negotiations are underway ... Meanwhile, APAV will soon take its first steps on the slopes of the new Rhodson 1078 R, which we also present to you. A French invention on a French motorcycle (with a Ducati engine), we can't wait to see the result and keep you updated on progress!
