Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
I thought these PUs would need interference valves in order to keep the compression ratio as high as possible.GhostF1 wrote:Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.
Then add that to this new behaviour which has been prevalent since Spec 4 and the new Mobil fuel was brought in, it seems clear they are efficient enough ICE side to have excess fuel to play with and as such have introduced what is sounding like an antilag system by dumping fuel into the switched off cylinders while skip fire is active (the big bangs and pops). This would have two benefits:
1. Piston/Cylinder cooling from cool fuel injection
2. Causing backfires when it passes into the exhaust unburnt, keeping the turbo spooled without requiring electrical energy use from the MGU-H.
The negative to antilag is turbine damage, however this could be something HondaJet is assisting with on designing impellers that can withstand the shock damage and the sudden heat rise.
They more than likely would yesJonoNic wrote: ↑01 Mar 2020, 03:28I thought these PUs would need interference valves in order to keep the compression ratio as high as possible.GhostF1 wrote:Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.
Then add that to this new behaviour which has been prevalent since Spec 4 and the new Mobil fuel was brought in, it seems clear they are efficient enough ICE side to have excess fuel to play with and as such have introduced what is sounding like an antilag system by dumping fuel into the switched off cylinders while skip fire is active (the big bangs and pops). This would have two benefits:
1. Piston/Cylinder cooling from cool fuel injection
2. Causing backfires when it passes into the exhaust unburnt, keeping the turbo spooled without requiring electrical energy use from the MGU-H.
The negative to antilag is turbine damage, however this could be something HondaJet is assisting with on designing impellers that can withstand the shock damage and the sudden heat rise.
I probably worded that a bit rough. Variable Valve Timing systems are not permitted by the rules so by "having the valves open" I'm just implying the known, in that they run a normal cycle without combustion taking place.
efficiency loss with throttling is far more than 'pumping loss'GhostF1 wrote: ↑01 Mar 2020, 03:21....the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.......
Indeed. Exactly why it was theorised earlier in this thread that Honda PU torque demand from the driver was controlled by various combinations of fired and skipped cycles which give a range from 0-100%. Skip fire can provide solid progressive torque control. This then leaves the "throttling" issues you mention as redundant.Tommy Cookers wrote: ↑01 Mar 2020, 11:51efficiency loss with throttling is far more than 'pumping loss'GhostF1 wrote: ↑01 Mar 2020, 03:21....the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.......
because throttling reduces the peak temperature of the thermodynamic cycle and so reduces conversion of heat into work
yes both are alleviated by 'cylinder cutting'
(conventionally both in effect reduce motor size by rematching the motor/load relationship - this is the basis of driving)
with this supercharging pumping loss with throttling is trivial (the compressor work greatly reduces with throttling)
that's how WW2 was won
often when the ICE is at low powers it's driving the K into 'recovery'
further alleviating efficiency loss
this might supervene some more tradition-based views of effects within the ICE
Hmm. I think the skip fire the farting noises. The other cars have this farting noise too. The sort of noise you here when you turn over an engine without ignition. (take the spark plugs out and)GhostF1 wrote: ↑01 Mar 2020, 03:21Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.
Then add that to this new behaviour which has been prevalent since Spec 4 and the new Mobil fuel was brought in, it seems clear they are efficient enough ICE side to have excess fuel to play with and as such have introduced what is sounding like an antilag system by dumping fuel into the switched off cylinders while skip fire is active (the big bangs and pops). This would have two benefits:
1. Piston/Cylinder cooling from cool fuel injection
2. Causing backfires when it passes into the exhaust unburnt, keeping the turbo spooled without requiring electrical energy use on the MGU-H to do so, the saved energy can then be stored for use by the MGU-K during maximum power modes.
The negative to antilag is turbine damage, however this could be something HondaJet is assisting with on designing impellers that can withstand the shock damage and the sudden heat rise.
They mention 2011 2012. Are they suggesting the afterburn is to assist the aero?Revs84 wrote: ↑01 Mar 2020, 14:26Just found this article related to the current discussion.
https://it.motorsport.com/f1/news/test- ... o/4706019/
What about using the anti lag to charge the MGU-H?GhostF1 wrote: ↑01 Mar 2020, 03:21Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.
Then add that to this new behaviour which has been prevalent since Spec 4 and the new Mobil fuel was brought in, it seems clear they are efficient enough ICE side to have excess fuel to play with and as such have introduced what is sounding like an antilag system by dumping fuel into the switched off cylinders while skip fire is active (the big bangs and pops). This would have two benefits:
1. Piston/Cylinder cooling from cool fuel injection
2. Causing backfires when it passes into the exhaust unburnt, keeping the turbo spooled without requiring electrical energy use on the MGU-H to do so, the saved energy can then be stored for use by the MGU-K during maximum power modes.
The negative to antilag is turbine damage, however this could be something HondaJet is assisting with on designing impellers that can withstand the shock damage and the sudden heat rise.
Actually etusch makes a good point.saviour stivala wrote: ↑29 Feb 2020, 11:23Sounds like Honda can afford to waste a lot of fuel while on track.etusch wrote: ↑29 Feb 2020, 11:10After @godlameroso's post I started to think these
During braking they can cease combusting in the cylinder and injecting fuel later than normal time to send fuel to exhaust and burn there. May be burning can start in exhaust stroke. I don't know. Hope someone come up with good explanation.
Yeah for sure. Poor wording but it's what I was getting at with the bold sentence.godlameroso wrote: ↑02 Mar 2020, 00:39What about using the anti lag to charge the MGU-H?GhostF1 wrote: ↑01 Mar 2020, 03:21Yeah I would agree, the "rattattatatata" noise definitely sounds like skip fire operation which allows for varying combinations of cylinders to be cut off with the exhaust valves still open, significantly reducing pumping losses, increasing efficiency. And varying combinations of cylinder cuts would affect how "intense" the operation would be.NL_Fer wrote: ↑29 Feb 2020, 18:20Well the rattattataattaa sound is the ICE firing only 3 cylinders under breaking. The deactivated cylinders could be pumping just air, cooling the turbocharger.
Also, the F2 cars are spitting real flames almost half of all their races. The turbo’s are much more durable and antilag more controlled nowadays.
Doing this, reduces natural spark ignition engine braking, BUT, they could be using the MGU-K to compensate.
So let's think, if we assume skip fire (the "Honda noise") is to reduce pumping losses, there is a gain there in overall efficiency, what you do lose though is natural engine braking but this would allow the programming of the MGU-K, in full generation mode, to recover much more energy in slowing the engine down when off throttle or braking as it would not be competing with spark engine overrun resistance.. Ingenious.
Then add that to this new behaviour which has been prevalent since Spec 4 and the new Mobil fuel was brought in, it seems clear they are efficient enough ICE side to have excess fuel to play with and as such have introduced what is sounding like an antilag system by dumping fuel into the switched off cylinders while skip fire is active (the big bangs and pops). This would have two benefits:
1. Piston/Cylinder cooling from cool fuel injection
2. Causing backfires when it passes into the exhaust unburnt, keeping the turbo spooled without requiring electrical energy use on the MGU-H to do so, the saved energy can then be stored for use by the MGU-K during maximum power modes.
The negative to antilag is turbine damage, however this could be something HondaJet is assisting with on designing impellers that can withstand the shock damage and the sudden heat rise.