Tommy Cookers wrote:Craigy wrote:flexcon wrote:Here is another clip I took just now.
Whilst the sound we are familiar with sounds great like a devil, this changing gears in 5th 6th and 7th is awful!! [urlhttps://youtu.be/_RPtcv35b1U[/url]
Agreed.Crackpot theory: Honda are using the ERS-K to provide a quick torque fix to rev-match the engine to the gearbox, and that's currently failing for some control reason, meaning that the engagement is very harsh.
imo not crackpot
the K is geared to the crankshaft about 3:1 ie if unenergised its inertia substantially degrades and/or slows the shift
it is presumably energised ie continuously controlled to contribute as far as it can to emulate the ICE control for shift performance
ie momentary generator action to reduce its rpm as quickly as possible with upshift, minimising disruption in smoothness and speed of the shift
and similarly momentary motor action to increase its rpm as quickly as possible with downshift
if there was no spare energy in the ES the system would not work as intended
for this situation the fallback would be slower settings of the ICE and gearbox response to the shift demand
without the fallback (when needed) the shifts would show mechanical distress
the K is geared slightly higher than 3 - considering that the effective inertia goes up by the square of the gear ratio - the engine sees about 10 times the actual inertia of the K ! That is bound to tickle a torsional frequency (likely even more) at some point.
Whatever cylinder deactivation shenanigans they do at part throttle, full throttle will always be a nasty uneven firing with a strong 1.5th order and its higher harmonics - 3rd , 4.5th 6th etc. If you were to draw a campbell diagram of this mess you'd be hard pressed to find something that does NOT resonate at some point.
And when's the worst time to hit a resonance ? Surely under the high transient response during a gearshift.
