But there is still air going in and out of the cylinders, that's the point, because the throttle isn't fully closed like an air tight seal.AR3-GP wrote: ↑21 Jun 2023, 15:28There's a point here, but I think you've gone the wrong way about it.Just_a_fan wrote: ↑21 Jun 2023, 15:18The throttle isn't entirely closed when the throttle isn't pressed. If it was, the engine would stall for a lack of any oxygen to burn. Thus, cold pumping still happens.saviour stivala wrote: ↑21 Jun 2023, 13:23When the driver goes off-the-throttle-pedal the engine throttles are closed, as soon as the throttles to each cylinder are closed the pistons inside those cylinders cannot pump anything out of the exhaust valve as they cannot breathe any air. When pistons cannot breathe any air, and have nothing to push into the turbine, the turbine is as good as useless in regards powering/rotating the MGU-H, which when switched into recovery itself needs power so as to harvest/recover. It will be acting like a brake with the turbine having no power to overtake that brake effect.
It's true that an engine has to "idle" when it's disengaged from the transmission by the clutch.
However, when the car is moving at 300km/h and you take your foot off, there is no "throttle input". the engine doesn't "stall" because it's rotation is being driven by the connection between the wheels and the crankshaft. This is a bit like coasting a manual transmission car in gear. There is no fuel input. Only when you put the clutch in do the revs fall to idle revs and idle fueling.