Mercedes Power Unit Hardware & Software

[holeindalip]

Mercedes has been having problems since last year. Remember Perez engine in Bahrain and Abu Dhabi? And there was a rumor that they were running very conservative in Abu Dhabi because they were afraid of it blowing up.

Not the ice though, just the mgu-k

[Stu]

Another new engine for Bottas in Austin. What's the strategy here?

ICE only, 5 place drop only. most likely testing for next year.

Yeah, I think so too ...

In the team thread, I wrote about "there are rumours saying that the 3rd spec PU was built with an eye toward the E10 biofuel that should be used in 2022. Thus BOT`s 4th PU at Monza was run with special mapping in order to see had they could compensate some 65HP that they`ll lose with the new fuel ...

The same rumours are also saying that 2021 Merc PU having to cope with more races/km than last year was wear out at a faster rate towards their end of the duty cycle than it was designed for and the reason for that is the fierce battle between them and RB/Honda, which forced them to use more and more aggressive PU mappings in races, all coming with some negative consequences: they have found some issues at the crankshaft and valve seats ..."

The bit about Bottas’ special engine map can only be a ‘rumour’, surely? Weren’t the rules framed around a single ICE map per engine manufacturer per weekend when they got rid of multiple engine maps last year?

[Just_a_fan]

ICE only, 5 place drop only. most likely testing for next year.

Yeah, I think so too ...

In the team thread, I wrote about "there are rumours saying that the 3rd spec PU was built with an eye toward the E10 biofuel that should be used in 2022. Thus BOT`s 4th PU at Monza was run with special mapping in order to see had they could compensate some 65HP that they`ll lose with the new fuel ...

The same rumours are also saying that 2021 Merc PU having to cope with more races/km than last year was wear out at a faster rate towards their end of the duty cycle than it was designed for and the reason for that is the fierce battle between them and RB/Honda, which forced them to use more and more aggressive PU mappings in races, all coming with some negative consequences: they have found some issues at the crankshaft and valve seats ..."

The bit about Bottas’ special engine map can only be a ‘rumour’, surely? Weren’t the rules framed around a single ICE map per engine manufacturer per weekend when they got rid of multiple engine maps last year?

I wonder if the the map and ICE are considered a single item with respect to that rule - a new engine requiring a different map which won't work on the previous version engine and the old map not working on the new engine either, for example (an extreme example but only to make the point). At that point, the other teams would get the map/engine when their scheduled swap came due. That would be within the rules, unless they state specifically otherwise.

[pursue_one's]

It seems Mercedes will push the limits of their engines at the expense of durability.

"The data that emerged after the American race are encouraging and the intention would be to take risks in the next GPs, raising the boost very close to the reliability limit in order to extract about ten more horsepower in that threshold which is no longer the comfort zone of Hywel Thomas' motorists."

If Lewis Hamilton gets the opportunity to keep up with the Dutchman's Red Bull RB16B, there is a desire not to back down in the "engine war".

"The considerations that have been made are quite simple: even if a power unit were to break, Lewis would still remain second, so it is worth taking some risks to try to fight at the top."

https://it.motorsport.com/f1/news/f1-me ... e/6727158/

[Marty_Y]

It seems Mercedes will push the limits of their engines at the expense of durability.

"The data that emerged after the American race are encouraging and the intention would be to take risks in the next GPs, raising the boost very close to the reliability limit in order to extract about ten more horsepower in that threshold which is no longer the comfort zone of Hywel Thomas' motorists."

If Lewis Hamilton gets the opportunity to keep up with the Dutchman's Red Bull RB16B, there is a desire not to back down in the "engine war".

"The considerations that have been made are quite simple: even if a power unit were to break, Lewis would still remain second, so it is worth taking some risks to try to fight at the top."

https://it.motorsport.com/f1/news/f1-me ... e/6727158/

But wouldn't a DNF ruin any chance of winning the WCC?

It's a very high stakes gamble.

[godlameroso]

Perhaps something was lost in translation. If Hamilton's engine wear is more than anticipated and the engine loses some power as a result they'd still have a car fast enough to finish on the podium.

[atanatizante]

Some rumours about PU gaining some 630g weight due to changing some sealants (due to running higher than usual engine/PU maps with this 3rd PU and probably allowed by the FIA) that led to a 10HP increase in power output or maybe due to finally getting the only update this year for fuel & lube and other stuff here on Missed Apex Podcast:



In addition, what effect should have at Mexico race the new air intake plenum, bear in mind the low O2 per cent in the air due to high altitude?

Could all those above have determined BOT to say that now their PU is more powerful and "optimised" for the Mexico race?

https://www.motorsport.com/f1/news/merc ... e/6737155/

[Tommy Cookers]

... bear in mind the low O2 per cent in the air due to high altitude?

well no .... altitude makes no difference ....
the percentage of 02 in the Mexico City air is the same as the percentage of 02 in the air at sea level etc

btw high % water vapour correspondingly displaces all the other constituents of air eg by maybe 8% at Singapore
but % water vapour always low at altitude

[Mattchu]

... bear in mind the low O2 per cent in the air due to high altitude?

well no .... altitude makes no difference ....
the percentage of 02 in the Mexico City air is the same as the percentage of 02 in the air at sea level etc

btw high % water vapour correspondingly displaces all the other constituents of air eg by maybe 8% at Singapore
but % water vapour always low at altitude

From what I`m aware off Tommy this is not entirely true (happy to be proved wrong)! Well not according to this.

https://www.iqair.com/us/mexico/mexico-city

In Mexico City, a cubic meter of air contains 212 grams of oxygen, while at sea level it contains 275. The combustion efficiency of a well-tuned car is 92 per cent, and in the DF 69 per cent, due to the higher altitude.

[dans79]

... bear in mind the low O2 per cent in the air due to high altitude?

well no .... altitude makes no difference ....
the percentage of 02 in the Mexico City air is the same as the percentage of 02 in the air at sea level etc

btw high % water vapour correspondingly displaces all the other constituents of air eg by maybe 8% at Singapore
but % water vapour always low at altitude

From what I`m aware off Tommy this is not entirely true (happy to be proved wrong)! Well not according to this.

https://www.iqair.com/us/mexico/mexico-city

In Mexico City, a cubic meter of air contains 212 grams of oxygen, while at sea level it contains 275. The combustion efficiency of a well-tuned car is 92 per cent, and in the DF 69 per cent, due to the higher altitude.

take a look at this it simplifies a lot of otherwise complex information for easy consumption. this is in relation to altitudes a human would survive at.
https://media.nationalgeographic.org/as ... titude.pdf


take a look at this if you want to know about everything up to 1000 km.
http://wordpress.mrreid.org/2014/08/01/ ... elevation/

[Tommy Cookers]

In Mexico City, a cubic meter of air contains 212 grams of oxygen, while at sea level it contains 275. The combustion efficiency of a well-tuned car is 92 per cent, and in the DF 69 per cent, due to the higher altitude.

yes a cubic metre of MC air contains 212 gm of oxygen (77% of the sea level amount) ....
but only 77% of the SL amount of nitrogen, 77% of the SL amount of Argon etc etc
that's why a MC cubic metre of air is 77% of the weight of a SL cubic metre of air (ie the MC air pressure is less)

unlike NA F1 the hybrid F1 turbocharger can in principle compensate by pushing in more cubic metres of MC air per min
this requires a higher pressure ratio - in doing this the compressor etc is less efficient
and the higher PR will require higher turbo rpm which costs MGU-H efficiency - and this rpm is rule-limited to 125000

all reasons why one make of engine might be better at MC than another make (when not better elsewhere)

[NL_Fer]

I remember in the first years it was the smaller turbo’s which ran already closer to the 125000rpm limit and had less headroom, compared to the bigger Renault turbo, which ran a lower average rpm on sealevel.

[atanatizante]

...

yes a cubic metre of MC air contains 212 gm of oxygen (77% of the sea level amount) ....

...

I think you confused volume percentage within a gases composition with mass percentage due to altitude/pressure ...

Indeed, both at sea level and altitude we have the same 20.947 volume % of O2 in 1 cubic meter of air, as you correct above stated. But this volume weights differently at different altitudes/pressures due to the ideal gas law: pV=nRT. Thus, at the same volume when pressure lowers due to altitude we have fewer molecules so less mass or weight of O2 as Mattchu said in another post above ...

Anyway, no one has an idea how the ICE would cope with the new air intake plenum here in Mexico, bearing in mind it was designed to provide cooler air hence feeding more O2 for the engine?

[RonMexico]

Some rumours about PU gaining some 630g weight due to changing some sealants (due to running higher than usual engine/PU maps with this 3rd PU and probably allowed by the FIA) that led to a 10HP increase in power output or maybe due to finally getting the only update this year for fuel & lube and other stuff here on Missed Apex Podcast:



In addition, what effect should have at Mexico race the new air intake plenum, bear in mind the low O2 per cent in the air due to high altitude?

Could all those above have determined BOT to say that now their PU is more powerful and "optimised" for the Mexico race?

https://www.motorsport.com/f1/news/merc ... e/6737155/

Not a reliable source, you might say they are particularly unreliable even

[gruntguru]

yes a cubic metre of MC air contains 212 gm of oxygen (77% of the sea level amount)

I think you confused volume percentage within a gases composition with mass percentage due to altitude/pressure ...

Indeed, both at sea level and altitude we have the same 20.947 volume % of O2 in 1 cubic meter of air, as you correct above stated. But this volume weights differently at different altitudes/pressures due to the ideal gas law: pV=nRT. Thus, at the same volume when pressure lowers due to altitude we have fewer molecules so less mass or weight of O2 as Mattchu said in another post above ...

Anyway, no one has an idea how the ICE would cope with the new air intake plenum here in Mexico, bearing in mind it was designed to provide cooler air hence feeding more O2 for the engine?

Tommy is not confused. Percentage is not the correct term for specifying the number of molecules or grams of oxygen in a given volume of air. Percentage is a dimensionless term ie g/100g or L/100L.

If the Mercedes plenum does provide cooler air to the engine it will indeed reduce the PR required from the turbocharger compressor and that would of course be an advantage at altitude.

OTOH if Mercedes has taken advantage of the cooler intake air and reduced compressor size to improve power at sea level, they are back to square one when moving to high altitude.