2025/2026 Hybrid Powerunit speculation

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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''So 2mj is recovered by MGU-H while driving with open waste-gate/s'' While driving with open waste-gates the MGU-H is in motoring mode and while motoring it cannot also harvest.

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yelistener
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Re: 2025/2026 Hybrid Powerunit speculation

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wuzak wrote:
Thu Nov 24, 2022 7:03 am
yelistener wrote:
Thu Nov 24, 2022 12:33 am
wuzak wrote:
Wed Nov 23, 2022 3:43 am


You wouldn't happen to have ones for Spa and Azerbijan?
Spa is zero full boost. Baku is like 0.5s at the exit of the last real corner. They're too little so it's not worth making a video.

It can be a bit different with other teams. Some cars' exhaust mic don't give away the full boost sound, so we can't know.
Thanks.

I guess they have sections that are full throttle for so long that there isn't enough energy to do full boost.
They probably had full boost in Spa quali pre-2017. I remember that Honda magazine showed that in Spain the full boost happened in some part of the track in 2016 where there was none in 2017, and the difference is not exactly tiny. This could indicate recovering energy also happens during overrun (mid-corner no braking), or partial throttle at corner exit.
Last edited by yelistener on Fri Nov 25, 2022 8:21 am, edited 1 time in total.

johnny comelately
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Re: 2025/2026 Hybrid Powerunit speculation

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Just a query re waste gate opening
If audio analysis is being used is it possible that the change in pitch could be from the extra load coming on from the G being activated?

NL_Fer
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Re: 2025/2026 Hybrid Powerunit speculation

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saviour stivala wrote:
Thu Nov 24, 2022 9:14 pm
''So 2mj is recovered by MGU-H while driving with open waste-gate/s'' While driving with open waste-gates the MGU-H is in motoring mode and while motoring it cannot also harvest.
Could be yes.

Actually there is no indication there is 4MJ recovery/harvest and since this a qualifying lap, probably there isn’t. On a Q lap they drain the battery to end reach the finish line with 0% Soc for the ES.

But 4MJ is not enough for 28.5s of Deployment for both ES to K and ES to H driving the turbine. So probably there is still 1-2MJ of recovery done OR the turbocharger can run on exhaust energy with open wastegates, and the MGU-H is idle or in low power harvesting or motoring.

There is no reason to assume the waste-gates are simple on-off, but 0-100% controllable open close. Just like on our turbocharged street car.

saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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It, the turbocharger turbine used in F1 being a pressure type of turbine + the waste-gate/s used are designed to bypass exhaust gases from the turbine, when waste-gate/s are open the turbine is simply riding along on the turbo shaft while the whole thing is motored by the 'H', which in turn is sharing 'ES' power with 'K'. (electric supercharging mode/free load mode).

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yelistener
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Re: 2025/2026 Hybrid Powerunit speculation

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Mercedes actually posted a video on youtube including a small part explaining this wastegate open mode. They call it "AMG turbo mode", which Hywel Thomas said MGU-H was being powered in that mode and not harvesting energy.

Explanation starting at 10:36

johnny comelately
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Re: 2025/2026 Hybrid Powerunit speculation

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yelistener wrote:
Fri Nov 25, 2022 8:30 am
Mercedes actually posted a video on youtube including a small part explaining this wastegate open mode. They call it "AMG turbo mode", which Hywel Thomas said MGU-H was being powered in that mode and not harvesting energy.

Explanation starting at 10:36
https://youtu.be/RwwUOYTbyfs?t=635
OK that makes sense now (takes a while)
waste gate open compressor run e mode

Tommy Cookers
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Re: 2025/2026 Hybrid Powerunit speculation

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saviour stivala wrote:
Fri Nov 25, 2022 8:02 am
It, the turbocharger turbine used in F1 being a pressure type of turbine + the waste-gate/s used are designed to bypass exhaust gases from the turbine, when waste-gate/s are open the turbine is simply riding along on the turbo shaft while the whole thing is motored by the 'H', which in turn is sharing 'ES' power with 'K'. (electric supercharging mode/free load mode).
the above is incorrect ......
unless the exhaust gas is entirely diverted away from the turbine and the main exhaust pipe

but .....
the turbine actually gets 1 atm exhaust so kinetic pulses/waves still (quite weakly) power the turbine and compressor
this power recovery-without-backpressure is the so-called blowdown recovery
here it somewhat reduces the amount of ES energy needed by the MGU-H in driving the compressor
so increasing the available duration of this ('electric supercharge') running mode

there is no evidence that the turbine responds only to mean exhaust pressure (is unresponsive to kinetic 'pulses')
clearly all 4 makes of ICE have exhaust manifolds designed to encourage these pulses
and the pulses are anyway relatively stronger in 1 atm exhaust than in the main ('backpressure') running mode


fortunately for us there is no MGU-H and so no 'electric supercharge' in 2026 hybrid F1

saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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yelistener wrote:
Fri Nov 25, 2022 2:24 am
wuzak wrote:
Thu Nov 24, 2022 7:03 am
yelistener wrote:
Thu Nov 24, 2022 12:33 am


Spa is zero full boost. Baku is like 0.5s at the exit of the last real corner. They're too little so it's not worth making a video.

It can be a bit different with other teams. Some cars' exhaust mic don't give away the full boost sound, so we can't know.
Thanks.

I guess they have sections that are full throttle for so long that there isn't enough energy to do full boost.
They probably had full boost in Spa quali pre-2017. I remember that Honda magazine showed that in Spain the full boost happened in some part of the track in 2016 where there was none in 2017, and the difference is not exactly tiny. This could indicate recovering energy also happens during overrun (mid-corner no braking), or partial throttle at corner exit.
It took some of the power unit makers up to 2017 - 18 to believe that they have reached the top - which was back then producing an MGU-K that can deliver 120kw, it's fully permitted potential. Those two that believed so have than turned their attention to catch-up in how they can gain some 'EXTRA' harvesting even if it could potentially be considered not within the spirits of the harvesting energy rules, This line of thinking was as a consequence of lack of policing by the rule makers, which in turn was due to technical problems to do so. This can be confirmed by the late Charlie W saying that there was no way they could properly understand what FERRARI were doing until they produced and made use of very sophisticated software. Since then and since they introduced mandatory upgraded MGU-K IN - OUT sensors, this was right after the Japanese magazine outed the Honda 'EXTRA' HARVESTING which many on here promptly declared as being legal.

saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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Tommy Cookers wrote:
Fri Nov 25, 2022 3:33 pm
saviour stivala wrote:
Fri Nov 25, 2022 8:02 am
It, the turbocharger turbine used in F1 being a pressure type of turbine + the waste-gate/s used are designed to bypass exhaust gases from the turbine, when waste-gate/s are open the turbine is simply riding along on the turbo shaft while the whole thing is motored by the 'H', which in turn is sharing 'ES' power with 'K'. (electric supercharging mode/free load mode).
the above is incorrect ......
unless the exhaust gas is entirely diverted away from the turbine and the main exhaust pipe

but .....
the turbine actually gets 1 atm exhaust so kinetic pulses/waves still (quite weakly) power the turbine and compressor
this power recovery-without-backpressure is the so-called blowdown recovery
here it somewhat reduces the amount of ES energy needed by the MGU-H in driving the compressor
so increasing the available duration of this ('electric supercharge') running mode

there is no evidence that the turbine responds only to mean exhaust pressure (is unresponsive to kinetic 'pulses')
clearly all 4 makes of ICE have exhaust manifolds designed to encourage these pulses
and the pulses are anyway relatively stronger in 1 atm exhaust than in the main ('backpressure') running mode
It is your accredits which are wrong. First. Any exhaust gas past the exhaust valve is 'blow-down' gas. Secondly. The turbine used in F1 is not a blow-down turbine like used by the Wright Cyclone, but a pressure turbine. A blow-down turbine will not have a waste-gate because it doesn't need pressure to produce useful work. The F1 turbine needs exhaust gas pressure to produce useful work, when waste-gate/s are opened the exhaust gas pressure is dropped to atmospheric pressure, and any gases inside the turbine at atmospheric pressure cannot make the turbine do any useful work because turbine can only do so under exhaust gas pressure.