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Re: Mercedes Power Unit Hardware & Software
Posted: 05 Aug 2019, 22:03
by saviour stivala
roon wrote: ↑04 Aug 2019, 04:21
Well, I never got that nuanced with it.
Who knows what Renault, RB, and Ferrari were/are doing with WG aero... DF related, drag related...
The turbine here is unique from other non-MGU assisted applications in that it will maintain its rotational speed when the WG are opened. FWIW I'm asking, proffering, not proclaiming.
Basically, in the absence of, or in the reduction of, a pressure differential, does a centrifugal turbine become a centrifugal pump?
When the wastegate/s are opened its rotational speed will increase.
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 18:30
by 63l8qrrfy6
saviour stivala wrote: ↑05 Aug 2019, 22:03
roon wrote: ↑04 Aug 2019, 04:21
Well, I never got that nuanced with it.
Who knows what Renault, RB, and Ferrari were/are doing with WG aero... DF related, drag related...
The turbine here is unique from other non-MGU assisted applications in that it will maintain its rotational speed when the WG are opened. FWIW I'm asking, proffering, not proclaiming.
Basically, in the absence of, or in the reduction of, a pressure differential, does a centrifugal turbine become a centrifugal pump?
When the wastegate/s are opened its rotational speed will increase.
Why ?
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 18:41
by El Scorchio
Question about the Merc engine. Excuse me for not being much of an engine expert here, and this could be quite simplistic, but where does it now stack up against the other power units?
Back at the start of the hybrid era the Merc powered cars were right up there in most races with much attributed to the engine. Now we see racing point and Williams often out in q1 behind Renault, honda and Ferrari powered cars and the works team themselves often down on speeds and relying on downforce and aero packages instead of engine power to achieve lap times.
Has it now been overtaken by the other manufacturers or are they constantly running it below potential for reliability? Even if chasing a pole or a position you don’t see them flick a switch and suddenly increase speed and power substantially.
What is the opinion of the engine experts on here?
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 19:09
by MtthsMlw
El Scorchio wrote: ↑06 Aug 2019, 18:41
Question about the Merc engine. Excuse me for not being much of an engine expert here, and this could be quite simplistic, but where does it now stack up against the other power units?
Back at the start of the hybrid era the Merc powered cars were right up there in most races with much attributed to the engine. Now we see racing point and Williams often out in q1 behind Renault, honda and Ferrari powered cars and the works team themselves often down on speeds and relying on downforce and aero packages instead of engine power to achieve lap times.
Has it now been overtaken by the other manufacturers or are they constantly running it below potential for reliability?
Even if chasing a pole or a position you don’t see them flick a switch and suddenly increase speed and power substantially.
What is the opinion of the engine experts on here?
I think the general consensus is that it is still the best in race trim in terms of fuel consumption and high engine mode availability. Some say they're down 10-15hp in Quali to Ferrari or that they can't run the MGU-K as long as them (that's seems to be a fact as of right now). I don't see how reliabilty should be an issue all of a sudden but they had cooling issues this year because they designed the radiators too small.
I wouldn't use Williams as an indicator for how good the Merc PU is...
I don't see how you get to that conclusion (marked bold) if anything I feel like they closed that Quali gap to Ferrari a bit but that might just be down to Ferrari now focussing on DF and taking a drag penalty.
No expert here as well obviously 
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 19:43
by saviour stivala
Mudflap wrote: ↑06 Aug 2019, 18:30
saviour stivala wrote: ↑05 Aug 2019, 22:03
roon wrote: ↑04 Aug 2019, 04:21
Well, I never got that nuanced with it.
Who knows what Renault, RB, and Ferrari were/are doing with WG aero... DF related, drag related...
The turbine here is unique from other non-MGU assisted applications in that it will maintain its rotational speed when the WG are opened. FWIW I'm asking, proffering, not proclaiming.
Basically, in the absence of, or in the reduction of, a pressure differential, does a centrifugal turbine become a centrifugal pump?
When the wastegate/s are opened its rotational speed will increase.
Why ?
When the wastegate/s are open the turbo is being spun by the H to full boost with the turbine free of any loading.
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 20:35
by Pyrone89
El Scorchio wrote: ↑06 Aug 2019, 18:41
Question about the Merc engine. Excuse me for not being much of an engine expert here, and this could be quite simplistic, but where does it now stack up against the other power units?
Back at the start of the hybrid era the Merc powered cars were right up there in most races with much attributed to the engine. Now we see racing point and Williams often out in q1 behind Renault, honda and Ferrari powered cars and the works team themselves often down on speeds and relying on downforce and aero packages instead of engine power to achieve lap times.
Has it now been overtaken by the other manufacturers or are they constantly running it below potential for reliability? Even if chasing a pole or a position you don’t see them flick a switch and suddenly increase speed and power substantially.
What is the opinion of the engine experts on here?
Guys correct me if I am wrong but the general consensus is as follow:
Power peak (quali): 1. Ferrari, 2. Mercedes, 3. Renault, 4. Honda
Sustained power (race): 1. Mercedes, 2. Ferrari, 3. Honda, 4. Renault
Weight: unknown
Fuel consumption: 1. Mercedes, 2. Honda, 3. Renault, 4. Ferrari (this category is harder to accurately judge)
Size: 1. Honda, 2. Mercedes, 3. Ferrari, 4. Renault
Reliability: 1. Mercedes, 2. Honda, 3. Ferrari, 4. Renault
Drivability (mapping): 1. Mercedes, 2. Ferrari, 3. Renault, 4. Honda
Re: Mercedes Power Unit Hardware & Software
Posted: 06 Aug 2019, 23:06
by Tommy Cookers
saviour stivala wrote: ↑06 Aug 2019, 19:43
Mudflap wrote: ↑06 Aug 2019, 18:30
saviour stivala wrote: ↑05 Aug 2019, 22:03
When the wastegate/s are opened its rotational speed will increase.
Why ?
When the wastegate/s are open the turbo is being spun by the H to full boost with the turbine free of any loading.
the rpm is under full control by the H all the time - changes of load on the turbine have no effect on the rpm
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 00:16
by AJI
Tommy Cookers wrote: ↑06 Aug 2019, 23:06
saviour stivala wrote: ↑06 Aug 2019, 19:43
Mudflap wrote: ↑06 Aug 2019, 18:30
Why ?
When the wastegate/s are open the turbo is being spun by the H to full boost with the turbine free of any loading.
the rpm is under full control by the H all the time - changes of load on the turbine have no effect on the rpm
Isn't there a provision in the rules for the H motor to be clutched?
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 02:33
by roon
AJI wrote: ↑07 Aug 2019, 00:16
Tommy Cookers wrote: ↑06 Aug 2019, 23:06
saviour stivala wrote: ↑06 Aug 2019, 19:43
When the wastegate/s are open the turbo is being spun by the H to full boost with the turbine free of any loading.
the rpm is under full control by the H all the time - changes of load on the turbine have no effect on the rpm
Isn't there a provision in the rules for the H motor to be clutched?
Yes, but this doesn't alter the point being made. In the absence of MGU control, WGO should cause a decrease in turbine speed. With MGU control, turbine speed should be a controlled value regardless of WG position.
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 03:22
by saviour stivala
AJI wrote: ↑07 Aug 2019, 00:16
Tommy Cookers wrote: ↑06 Aug 2019, 23:06
saviour stivala wrote: ↑06 Aug 2019, 19:43
When the wastegate/s are open the turbo is being spun by the H to full boost with the turbine free of any loading.
the rpm is under full control by the H all the time - changes of load on the turbine have no effect on the rpm
Isn't there a provision in the rules for the H motor to be clutched?
I haven’t checked the exact wording of the rules/regulations but I am sure that unless there was a change in rules/regulations Both MGU-H and MGU-K drives can be clutched.
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 04:01
by AJI
roon wrote: ↑07 Aug 2019, 02:33
AJI wrote: ↑07 Aug 2019, 00:16
Tommy Cookers wrote: ↑06 Aug 2019, 23:06
the rpm is under full control by the H all the time - changes of load on the turbine have no effect on the rpm
Isn't there a provision in the rules for the H motor to be clutched?
Yes, but this doesn't alter the point being made. In the absence of MGU control, WGO should cause a decrease in turbine speed. With MGU control, turbine speed should be a controlled value regardless of WG position.
I was only talking about Tommy's statement that
the rpm is under full control by the H all the time
The rest I agree with. I was merely looking for clarification on whether they do in-fact use a clutch?
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 08:33
by saviour stivala
“The turbo RPM is under full control of the ‘H’”. Nobody said it is not.
When the waste gates are opened it is a call/demand for maximum power output from the ‘power unit’. Maximum power output from the power unit calls for. Full fueling permitted. Maximum boost. Minimizing exhaust back pressure.
In this mode the compressor is being used in electric mode. Both the ‘H’ and the ‘K’ are sharing battery power. (The ‘K’ is also contributing to the output) that is why it is called maximum ‘POWER UNIT OUTPUT”.
When that call/demand is made (maximum power unit output) the turbo is certainly not running at full boost and full turbo RPM. So when the waste-gate/s open the turbo will be speeded up to it maximum RPM and boost.
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 12:10
by Dr. Acula
AJI wrote: ↑07 Aug 2019, 04:01
I was merely looking for clarification on whether they do in-fact use a clutch?
They can use a clutch if they want to. But i don't see a reason to actually use one. You would gain basically nothing but it would add extra weight and use up extra space.
Technical Regulations wrote:5.2.4 The MGU‐H must be solely mechanically linked to the pressure charging system. This
mechanical link must be of fixed speed ratio to the exhaust turbine and may be clutched.
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 14:14
by digitalrurouni
Pyrone89 wrote: ↑06 Aug 2019, 20:35
El Scorchio wrote: ↑06 Aug 2019, 18:41
Question about the Merc engine. Excuse me for not being much of an engine expert here, and this could be quite simplistic, but where does it now stack up against the other power units?
Back at the start of the hybrid era the Merc powered cars were right up there in most races with much attributed to the engine. Now we see racing point and Williams often out in q1 behind Renault, honda and Ferrari powered cars and the works team themselves often down on speeds and relying on downforce and aero packages instead of engine power to achieve lap times.
Has it now been overtaken by the other manufacturers or are they constantly running it below potential for reliability? Even if chasing a pole or a position you don’t see them flick a switch and suddenly increase speed and power substantially.
What is the opinion of the engine experts on here?
Guys correct me if I am wrong but the general consensus is as follow:
Power peak (quali): 1. Ferrari, 2. Mercedes, 3. Renault, 4. Honda
Sustained power (race): 1. Mercedes, 2. Ferrari, 3. Honda, 4. Renault
Weight: unknown
Fuel consumption: 1. Mercedes, 2. Honda, 3. Renault, 4. Ferrari (this category is harder to accurately judge)
Size: 1. Honda, 2. Mercedes, 3. Ferrari, 4. Renault
Reliability: 1. Mercedes, 2. Honda, 3. Ferrari, 4. Renault
Drivability (mapping): 1. Mercedes, 2. Ferrari, 3. Renault, 4. Honda
I would put the Honda and Ferrari at a tie in reliability. But agree with the rest of the list.
Re: Mercedes Power Unit Hardware & Software
Posted: 07 Aug 2019, 14:40
by Bill
Honda drivability is fantastic did you not read Max comments on how it's fair compared to Renault. You win a race in the rain unless your are confident on the throttle you need a predictable engine.we saw last in Singapore the Redbull shaking violently on mildly throttle input why would anyone think that great sign of great drivability,quite frankly I think the Honda is ahead of Renault in all dimensions spec4 will put a doubts away