Tommy Cookers wrote:the MGU-K has the same power 120 kW (and torque) limit in generation and motor action
but its motor action when running on stored electricity is in effect time-restricted by the lap energy-limit rule
when using electricity direct (real-time) from the MGU-H generation action the MGU-K motor action is of unlimited duration
ie the car is electrically propelled in part from KE recovered in braking and in part from exhaust energy semi-continuously recovered
in this way MGU-K motor action at or near 120 kW seems continuous whenever the driver is calling for max ICE power
afaik the flashing light tells us that the MU-K motor action has stopped, so generated current can be sent to storage
presumably this generated current is coming from GU-H action
(and one suspects also from GU-K action without the driver braking - others will be pleased to tell us if this is incorrect)
anyway after the flashing light process the car has less KE and less braking need than it would otherwise
So, if I understand correctly, you are saying that the rules stipulate that the extra 120kW that is available to the driver, from the MU-K, at the push of the button, for a limited time, is only based on the stored energy being used. Any energy that the GU-H is recovering (in its action as a wastegate-repalcement), can be sent to the batteries, or alternatively, it can be sent to the MU-K to propel the car, and this does not eat in to the allocation to the driver (for 'free' essentially). You are suggesting that this (GU-H > MU-K) is happening almost all the time, and in cases where the recovered energy is sent to storage instead of the MU-K, this is where the light flashes?
This makes a lot of sense, in any case, I still question the use of this. This would be a counter-intuitive action to take I would think, to send recovered energy to storage, instead of getting a 'free' boost at any WOT event? Because as soon as it goes to storage, it becomes 'metered' and no longer 'free'
yes, because of the 120 kW limit on GU-K action only a small fraction of the KE is recovered (especially at high lap-KE circuits)
and this recovery would allow full MU-K power for only part of the time the ICE is at full power
but also about 12% of the exhaust energy is recovered (by GU-H action), so powering the MU-K to complete its entitlement
no heat is recovered from coolant
I am not sure I follow here. I understand that only a small fraction of KE is recovered by the GU-K action, but if we say, hypothetically, that a particular braking event, at the beginning, generates approximately 1000kW, maybe 200 of that goes to aero, 680 goes to the brake rotors as heat, and 120 goes to the GU-K. The proportions (and total) will change, as the car slows during a braking event, but the 120 that goes to the GU-K should remain relatively constant, no? And since there is - I assume - more than 7 seconds of braking in total on a track, then you should be able to charge the batteries enough to then be able to dispense 120kW at will for the full amount of time.
some believe in other conditions energy directly ('real-time') from fuel burn is 'recovered' as electricity (ie driving against GU-K action)
technically (and 'morally') justifiable when the driver wants partial power, as generator load allows less ICE throttling than otherwise needed
because the ICE efficiency improves with less throttling, to an extent the generator is using fuel that otherwise would be wasted
This bit makes sense, as you could limit torque output to the wheels by driving against the GU-K action, instead of throttling the engine, improving efficiency, in the way of storing the extra energy. However this would not explain the flashing light/going slow, as the torque request of the driver's foot would still be fulfilled entirely, just through a different means.
Cold Fussion wrote:
I don't know for sure but I think the flashing rain light is when the the mgu-k is harvesting while the driver is lifting and coasting. As a fuel saving measure you'd normally lift and coast for variable amounts before the braking zone, with it being more efficient to charge the batteries at this point rather letting the aero do all the braking.
Ok, if you are fuel saving, I could understand this, but if someone is close enough behind you to see the flashing light, do you think you would be fuel saving, 'lift & coast'-ing? Or would you be defending, or keeping up the pace to keep them at bay? Instead of telling them "I'm going to be slow entering/exiting this corner, this could be an opportunity for you to overtake"