Mercedes Power Unit Hardware & Software

[MtthsMlw]

After the party mode ban you have to run the engine in the same mode (ERS excluded) from the beginning of Quali. Can this mode be set on a driver to driver basis? I vaguely remember that after a certain point one mode must be used by every customer or am I wrong? As far as I understand you can decide on another mode from weekend to weekend though.

[One and Only]

How is it possible to run your ICE so much harder with limited fuel flow? Last time someone had ICE performance like this there was fuel flow sensor saga. And that ICE could race for 7 races.

Because the ICE is normally run more conservatively in order to last 7 or 8 races. They'll run to a limited max revs, for example, and in this ICE they might be saying "you can have some extra revs" which will help give a higher top speed (gearing allowing, of course).

Still more power requires more energy, especially if you run high downforce configuration.
It would make sense if they usually run at ~95% of fuel flow limit and then decide to run it at 98% for example. It would be interesting to see how much fuel actually these cars use when driver hits full throttle.

[One and Only]

good question.
Either Mercedes made superior drag reduction somehow, or this engine has more than 100-150hp advantage - with same fuel flow, that would be what, 60% efficiency?
All based on Amus, that top speed without DRS was 15km/h higher for Hamilton

Hamilton's top speed figures weren't that much impressive. I think it was about 6km/h better than others without DRS. To me it looks he gained on others during whole acceleration phase.

[tok-tokkie]

This engine needs to do 4 races instead of the usual 7 or 8.
They had to turn it up to give Hamilton a chance at the WDC. He has delivered in spades.
But what can this engine do over the remaining 3 races?
Points 25 for #1 18 for #2 delta is 7. Verstappen is 14 ahead. He has a buffer but Hamilton is very reliant on his engine power being maintained for the next races. I expect them to again turn it up for the next race so Hamilton can get in the lead. Then he will nurse the engine as much as possible while he is in the lead.
Who gets the lead early in the next race is going to be very influential for the WDC.

[henry]

How is it possible to run your ICE so much harder with limited fuel flow? Last time someone had ICE performance like this there was fuel flow sensor saga. And that ICE could race for 7 races.

Because the ICE is normally run more conservatively in order to last 7 or 8 races. They'll run to a limited max revs, for example, and in this ICE they might be saying "you can have some extra revs" which will help give a higher top speed (gearing allowing, of course).

Still more power requires more energy, especially if you run high downforce configuration.
It would make sense if they usually run at ~95% of fuel flow limit and then decide to run it at 98% for example. It would be interesting to see how much fuel actually these cars use when driver hits full throttle.

I think it works like this.

The crank power comes from the pressure in the combustion chamber acting on the piston. To increase the crank power you bring forward the start of ignition so that the pressure is higher earlier in the expansion stroke. This is more efficient, so you get more power from the crank for the same amount of fuel.

The downside is that the timing and the rate of the pressure rise are not 100% repeatable and if the rise is too early the pressure peak comes too close, or even before, TDC and this puts shock loads into the combustion chamber, piston and bearings. So called knock. This fatigues the ICE And leads to failures.

So they typically run the ignition a little later so that they get no, or little knock, but less power.

They might also be able to get more power from the MGU-H by increasing the energy in the exhaust. This can help in three ways. In e-boost mode the drain on the ES is slightly less and in self-sustain plus the drain on the ES is less so these two modes can be used for longer each lap. In modes where the H is feeding the ES there is slightly more energy stored per lap.

These PUs are complex. Single peak power numbers do not tell the whole story.

[Just_a_fan]

How is it possible to run your ICE so much harder with limited fuel flow? Last time someone had ICE performance like this there was fuel flow sensor saga. And that ICE could race for 7 races.

Because the ICE is normally run more conservatively in order to last 7 or 8 races. They'll run to a limited max revs, for example, and in this ICE they might be saying "you can have some extra revs" which will help give a higher top speed (gearing allowing, of course).

The question is not of running harder.
Its about how they get so much better efficiency with same fuel amount

By using more revs. It's high revs that take life out of the engines. The gearing allows for higher top speeds than normal to allow for the higher speeds achieved when in the tow / when DRS is open, so it's just a matter of getting the engines to run at a higher speed when loaded.

[TimW]

Can't they simply run the ICE hotter to gain thermal efficiency?

[Juzh]

How is it possible to run your ICE so much harder with limited fuel flow? Last time someone had ICE performance like this there was fuel flow sensor saga. And that ICE could race for 7 races.

Because the ICE is normally run more conservatively in order to last 7 or 8 races. They'll run to a limited max revs, for example, and in this ICE they might be saying "you can have some extra revs" which will help give a higher top speed (gearing allowing, of course).

Revs never change, everyone always drives in 10500-12500 range because of how the rules are written. I've never seen anyone running below these numbers in a deliberate way, even when they are in complete cruise mode (verstappen in mexico for example). Because of that we also know they all run at their maximum fuel flow of 100 kg/h (because regs specify that number from 10500 rpm and up). Therefore engine saving is likely done by reducing turbo pressure, ignition timings and so on.

[Big Tea]

After the party mode ban you have to run the engine in the same mode (ERS excluded) from the beginning of Quali. Can this mode be set on a driver to driver basis? I vaguely remember that after a certain point one mode must be used by every customer or am I wrong? As far as I understand you can decide on another mode from weekend to weekend though.

I believe it has to be 'available' to all but not compulsory

[dans79]

I believe it has to be 'available' to all but not compulsory

That's correct, as anything else would be unfair. If they all had to run the same mode, then all the teams running the PU would be limited by the team with the worst cooling, intake, and exaust package!

[One and Only]

I believe it has to be 'available' to all but not compulsory

That's correct, as anything else would be unfair. If they all had to run the same mode, then all the teams running the PU would be limited by the team with the worst cooling, intake, and exaust package!

Not only unfair, but also illegal afaik. Customer teams must have same options.

[toraabe]

After the party mode ban you have to run the engine in the same mode (ERS excluded) from the beginning of Quali. Can this mode be set on a driver to driver basis? I vaguely remember that after a certain point one mode must be used by every customer or am I wrong? As far as I understand you can decide on another mode from weekend to weekend though.

All the modes has to be available to all customers. Whether they will use it is another question. And full beans really means full beans.

[Juzh]

After the party mode ban you have to run the engine in the same mode (ERS excluded) from the beginning of Quali. Can this mode be set on a driver to driver basis? I vaguely remember that after a certain point one mode must be used by every customer or am I wrong? As far as I understand you can decide on another mode from weekend to weekend though.

All the modes has to be available to all customers. Whether they will use it is another question. And full beans really means full beans.

They might be available as the regs stipulate that, but you can be sure not everyone uses same modes and they pretty much go with what mercedes tells them to use based on wear and probably a hundred other factors. For example hamilton with his brand new engine most definitely wasn't using same maps even compared to his teammate, let alone all other mercedes PU cars.

[djones]

I'm not so sure Hamilton has to nurse the engine. If that was the case why did he then clear Max by 10 seconds?

This means they are either super confident the engine will last to the end of the season or they have a strategy to change the engine again at the next race. If it's a track with long straights and a new engine mapped to last 1 race gives an advantage like in Brazil then it's actually a pretty solid idea??

[siskue2005]

I'm not so sure Hamilton has to nurse the engine. If that was the case why did he then clear Max by 10 seconds?

This means they are either super confident the engine will last to the end of the season or they have a strategy to change the engine again at the next race. If it's a track with long straights and a new engine mapped to last 1 race gives an advantage like in Brazil then it's actually a pretty solid idea??

As Lewis stated his tyres were still good after the pass on Max, and he was using them up instead of engine I presume.
Aswell as Max with his old engine would have turned his engine off completely

These two reasons are the cause of 10 sec gap