Honda Power Unit Hardware & Software

[etusch]

They do videos answering questions. Someone may ask. I guess toto just get it wrong

[hurril]

And those "bangs" that the Honda PU does when downshifting and off throttle, may be they are trying to recover from the MGU-H even if they aren't accelerating??

Beats me. If I had to guess, one [guess] might be that they are trying to avoid motoring the compressor in a situation where they've computed that using fuel is cheaper.

[Jaisonas]

Here's my take. Mercedes are already pushing their electronics to their limits while running the MGUK at the races.
An electric motor will pull a lot lot more current when its starting from a stopped position rather that when its already running, so its possible that their electronics cannot handle the current draw that requires.

[nzjrs]

Here's my take. Mercedes are already pushing their electronics to their limits while running the MGUK at the races.
An electric motor will pull a lot lot more current when its starting from a stopped position rather that when its already running, so its possible that their electronics cannot handle the current draw that requires.

Sure, but the interesting question is the one that this reading omits - why not adjust that tradeoff? And if they could previously start the engine from the K, what changed now that made the tradeoff land in a different place? What can we learn / speculate from that?

(BTW I've heard it said both ways the racing point can / can not start from the K. What is the final conclusion on this point?)

[PlatinumZealot]

Here's my take. Mercedes are already pushing their electronics to their limits while running the MGUK at the races.
An electric motor will pull a lot lot more current when its starting from a stopped position rather that when its already running, so its possible that their electronics cannot handle the current draw that requires.

That can be easily controlled with the drive.
You can set the ramp to prevent that.

[Winterapfel]

Here's my take. Mercedes are already pushing their electronics to their limits while running the MGUK at the races.
An electric motor will pull a lot lot more current when its starting from a stopped position rather that when its already running, so its possible that their electronics cannot handle the current draw that requires.

Sure, but the interesting question is the one that this reading omits - why not adjust that tradeoff? And if they could previously start the engine from the K, what changed now that made the tradeoff land in a different place? What can we learn / speculate from that?

(BTW I've heard it said both ways the racing point can / can not start from the K. What is the final conclusion on this point?)

The racing point can't either. During red flag q2 qualifying it was sitting in the que with the engine running (since it couldn't be turned if and then restarted), it overheated and had to be pushed from the que to the side..

[gruntguru]

''Does anybody know if it's possible to alter the combustion from race to race in order to produce more recoverable energy through the MGU-H?'' Yes. Different power unit modes are allowed to be selected for use for different tracks.

It is possible to significantly alter the combustion at any time, simply by adjusting the tuning parameters - for example:

1. Change the AFR by adjusting fuel injection quantity or boost.
2. Change the pre-chamber AFR (and combustion rate) by altering injection timing and multi-pulse phasing.
3. Change peak combustion temperature and pressure by altering boost, MAT, AFR, ignition timing.
4. Change EGT and blowdown energy using the same factors.
. . . . the list could go on and on - there is not much they can't adjust.

Having said that, it would be unusual to compromise the crankshaft output to increase exhaust energy. As I have said elsewhere - the result is less total energy recovered from the allocated fuel.

[hurril]

''Does anybody know if it's possible to alter the combustion from race to race in order to produce more recoverable energy through the MGU-H?'' Yes. Different power unit modes are allowed to be selected for use for different tracks.

It is possible to significantly alter the combustion at any time, simply by adjusting the tuning parameters - for example:

1. Change the AFR by adjusting fuel injection quantity or boost.
2. Change the pre-chamber AFR (and combustion rate) by altering injection timing and multi-pulse phasing.
3. Change peak combustion temperature and pressure by altering boost, MAT, AFR, ignition timing.
4. Change EGT and blowdown energy using the same factors.
. . . . the list could go on and on - there is not much they can't adjust.

Having said that, it would be unusual to compromise the crankshaft output to increase exhaust energy. As I have said elsewhere - the result is less total energy recovered from the allocated fuel.

I don't think it is unusual because this is not a steady state type of race. There are moments and cases where you want to charge the battery faster at the expense of efficiency _now_ to make a gain soon. You might want to have another go at an overtake sooner or just pick up the pace in general on parts of the track where it's more difficult to defend. (So you charge extra fast on areas where you can defend and run part throttle.)

[gruntguru]

It is possible to significantly alter the combustion at any time, simply by adjusting the tuning parameters - for example:

1. Change the AFR by adjusting fuel injection quantity or boost.
2. Change the pre-chamber AFR (and combustion rate) by altering injection timing and multi-pulse phasing.
3. Change peak combustion temperature and pressure by altering boost, MAT, AFR, ignition timing.
4. Change EGT and blowdown energy using the same factors.
. . . . the list could go on and on - there is not much they can't adjust.

Having said that, it would be unusual to compromise the crankshaft output to increase exhaust energy. As I have said elsewhere - the result is less total energy recovered from the allocated fuel.

I don't think it is unusual because this is not a steady state type of race. There are moments and cases where you want to charge the battery faster at the expense of efficiency _now_ to make a gain soon. You might want to have another go at an overtake sooner or just pick up the pace in general on parts of the track where it's more difficult to defend. (So you charge extra fast on areas where you can defend and run part throttle.)

"Charge the battery faster"? You may be right but the only circumstance where this might be the case would be where you want to charge faster than 120 kW (MGUK limit) + whatever the MGUH is making. At WOT this would give about 180 kW total charging rate without needing to compromise TE by retarding timing etc. (Power to the rear wheels would be about 420 kW?)

Retarding timing is a bit like electric supercharger mode - you have to give away a bit of fuel.

[henry]

I think the use of part throttle retarded timing to increase H recovery at the expense of crank power has been curtailed by two regulation changes this year.

Firstly the Regulation requirement that links fuel use to crank power seems to aimed at preventIng overfuelling at part throttle. I say seems because as yet I can’t make sense of the actual numbers In the regulation.

Secondly the Technical requirement to run the same ICE settings in qualification and race would likely make it less likely that people would run fuel inefficient settings at part throttle.

Both of these probably mean that they probably have relatively less energy to spend on e-boost in qualification compared with last season. Of course they may have recouped that with other improvements.

[henry]

"Charge the battery faster"? You may be right but the only circumstance where this might be the case would be where you want to charge faster than 120 kW (MGUK limit) + whatever the MGUH is making. At WOT this would give about 180 kW total charging rate without needing to compromise TE by retarding timing etc. (Power to the rear wheels would be about 420 kW?)

Retarding timing is a bit like electric supercharger mode - you have to give away a bit of fuel.

I think I observed Ferrari charging K+H at the end of straight at Hockenheim and their current speed traces suggest they may still be doing this with power to rear wheels dropping about 200kW ( from self sustain to max charge) Speed traces for the other PUs suggest they only charge using the H with a power drop of 120kW or so (self sustain to H charge).

I’m not sure I understand why e-boost gives away fuel? They’re running at max fuel flow then.

[saviour stivala]

Here's my take. Mercedes are already pushing their electronics to their limits while running the MGUK at the races.
An electric motor will pull a lot lot more current when its starting from a stopped position rather that when its already running, so its possible that their electronics cannot handle the current draw that requires.

Sure, but the interesting question is the one that this reading omits - why not adjust that tradeoff? And if they could previously start the engine from the K, what changed now that made the tradeoff land in a different place? What can we learn / speculate from that?

(BTW I've heard it said both ways the racing point can / can not start from the K. What is the final conclusion on this point?)

Power unit suppliers have to supply customers with the same hardware and software. which means if the Mercedes drivers cannot start/restart the engine, racing point driver also cannot.

[gruntguru]

I’m not sure I understand why e-boost gives away fuel? They’re running at max fuel flow then.

I was trying to find a simple way to say
"In an ideal world, you would run the PU at the operating point(s), that produce the maximum total energy to the tyres - summed over the race. Operating modes like electric supercharger or retarded timing will reduce the total energy available from the allocated fuel"

[saviour stivala]

Operating modes like electric supercharging is the only mode in which the maximum possible power can be extracted both from the ICE and the ERS (electrical part of the PU). In this mode the 'H' is motoring the compressor alone and not 'helping' the turbine to speed-up the compressor. At the same time that the 'H' is motoring the compressor it is sharing ES power with 'K'. This is being done with waste-gate fully open and the ICE at full fuel flow allowed. Extracting the maximum possible power from the ICE part of the PU means extracting the maximum energy possible from the max fuel flow allowed of which is being burned. certainly far from giving-away fuel. Extracting the maximum power output from the ICE part of the PU is only possible because the turbine part of the turbocharger is a 'pressure' turbine and so it converts 'blow-down velocity energy in manifold collector into pressure energy. and this conversion to pressure energy reflects on the scavenging ability of the cylinders. and that is exactly why that only with waste-gates fully open and with exhaust gasses at near atmospheric 'pressure' that the scavenging ability of the cylinders can be fully utilized.

[Craigy]

I’m not sure I understand why e-boost gives away fuel? They’re running at max fuel flow then.

I was trying to find a simple way to say
"In an ideal world, you would run the PU at the operating point(s), that produce the maximum total energy to the tyres - summed over the race. Operating modes like electric supercharger or retarded timing will reduce the total energy available from the allocated fuel"

However;
Deploying energy at certain parts of the circuit produces a more effective result than at others (eg. start of straight versus end of straight). Implicitly, recovering energy at certain parts of the circuit produces a more effective result than at others.
Energy deployed on certain laps produces a more effective result than at others (eg. start of race, restart after safety car, undercut, overcut laps, attempting to gain DRS, attempting to defend DRS, attempting an overtake/defending an overtake).
Hitting the overall shortest elapsed race time to get to 305Km is one thing, but for racing a compromise is needed between that and the amount of delta you can put into the performance to overproduce a few given special laps against lowering the performance available in the average laps.

You might put more energy through the drivetrain in a perfect world and still lose because of someone else compromising in order to gain track position on you.

My opinion: I see the split of "overperform laps" versus "averaged laps" as being a bit allegorical to developing the car's aero for running in clean versus dirty air.

TL;DR : F1 is not a time trial.