Twelve full piston displacements, ~15 (3*regulated value) fuel injection events, multiple spark events. How much piston and crankshaft speed can be expected to alter within one revolution, I don't know.
For a speed difference to exists between power unit and differential apart from the designed three-step drop ratio it can only exist through a slipping clutch, and a formula one car with a slipping clutch, no matter how small the slip might be, the clutch will just not last for any length of time or distance.roon wrote: ↑Wed May 15, 2019 2:10 pmTwelve full piston displacements, ~15 (3*regulated value) fuel injection events, multiple spark events. How much piston and crankshaft speed can be expected to alter within one revolution, I don't know.
Related: Is it also the compressibilty of air that is absorbing the the speed differential between transmission and engine? After these short seamless shifts.
Not in my opinion.roon wrote: ↑Wed May 15, 2019 12:38 amAdvancing combustion momentarily could provide some engine braking. Small fuel injection and ignition before TDC. Combustion events at about 600 Hz. 2 ms for one event, 12 ms for six. Time these early small braking ignitions after shift request, and prior to selector action and during any clutch activity. Combine with MGUK activity. Workable?
No - its the clutch. Even momentary additional slip in the tyres is a nightmare for the driver trying to control a racecar at the limit.
Okay, now if you add the H (what, 60kw?) generating, and the fact that you've shifted up a ratio, and that the driveshafts, etc, are deliberately built at quill shafts to absorb spikes at the limit of wheel grip, what do you actually end up with as a torque spike at the wheel?gruntguru wrote: ↑Thu May 16, 2019 6:14 amThe numbers are different to your gut feel unfortunately. Using a low rotational inertia for the engine plus MGUK of 0.05 kg.m^2 and a rpm change on upshift from 12,000 to 10,500 we get a change in kinetic energy of 18 kJ. (To achieve this in 1 second would require a braking power of 18 kW). The MGUK has a power limit of 120 kW so it will slow the engine from 12,000 to 10,500 in 0.15 sec (150 ms). That is way too slow for a gearshift. If the shift was say 15 ms, the braking power required to slow the engine would be 1200 kW.