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.
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lio007
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Re: 2025/2026 Hybrid Powerunit speculation

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Nice new piece from AMuS on the next-gen PU's:

https://www.auto-motor-und-sport.de/formel-1/f1-motor-2025-infos-daten/

Main new points seem to be:
  • Improve fuel efficiency at full load by 10%
  • Combustion engine will lose power and electric drive will gain power
  • Slightly larger, but more powerful batteries
  • Competition set to take place mainly on the electric side
  • Cost reduction on the combustion engine through measures like open-sourcing components
  • Allowing a more liberal relationship with electric energy management (may still cap power, but allow more freedom on energy within that limit)
  • Prescribed battery technologies (for cost reduction) but permitted freedom of design within that limit.
  • Bring back active driver decision over deployment with push-to-pass type features

mzso
mzso
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Re: 2025/2026 Hybrid Powerunit speculation

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lio007 wrote:
28 Feb 2021, 16:58
Nice new piece from AMuS on the next-gen PU's:

https://www.auto-motor-und-sport.de/formel-1/f1-motor-2025-infos-daten/

Main new points seem to be:
  • Improve fuel efficiency at full load by 10%
  • Combustion engine will lose power and electric drive will gain power
  • Slightly larger, but more powerful batteries
  • Competition set to take place mainly on the electric side
  • Cost reduction on the combustion engine through measures like open-sourcing components
  • Allowing a more liberal relationship with electric energy management (may still cap power, but allow more freedom on energy within that limit)
  • Prescribed battery technologies (for cost reduction) but permitted freedom of design within that limit.
  • Bring back active driver decision over deployment with push-to-pass type features
All in all feels rather bland.

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henry
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Re: 2025/2026 Hybrid Powerunit speculation

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If an objective is to help develop the road relevance of the electrics it might be sensible to reduce the number of gears. As @Tommy Cookers points out the MGU-K benefits from the many gears currently available allowing the K to have a limited speed range, in much the way the ICE is benefited.

Most road EVs have single speed* and have to operate over a wide speed range, albeit the speed range for most is less than half that of F1. If F1 reduced to 4 speed that would provide a challenge for the motor and controller electronics which might spill over to the road.

Personally I think the ICEs would sound better as well but that’s very subjective.

*Porsche use 2 speed on the Taycan are they only volume manufacturer to do so?
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Just_a_fan
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Re: 2025/2026 Hybrid Powerunit speculation

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henry wrote:
01 Mar 2021, 13:57
If an objective is to help develop the road relevance of the electrics it might be sensible to reduce the number of gears. As @Tommy Cookers points out the MGU-K benefits from the many gears currently available allowing the K to have a limited speed range, in much the way the ICE is benefited.

Most road EVs have single speed* and have to operate over a wide speed range, albeit the speed range for most is less than half that of F1. If F1 reduced to 4 speed that would provide a challenge for the motor and controller electronics which might spill over to the road.

Personally I think the ICEs would sound better as well but that’s very subjective.

*Porsche use 2 speed on the Taycan are they only volume manufacturer to do so?
F1 isn't an EV, is it? It's a hybrid. Hybrid road cars generally use a gearbox. Some run the electric motors directly to one axle, but many just use it to boost the input to the gearbox.
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Big Tea
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Joined: 24 Dec 2017, 20:57

Re: 2025/2026 Hybrid Powerunit speculation

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henry wrote:
01 Mar 2021, 13:57
If an objective is to help develop the road relevance of the electrics it might be sensible to reduce the number of gears. As @Tommy Cookers points out the MGU-K benefits from the many gears currently available allowing the K to have a limited speed range, in much the way the ICE is benefited.

Most road EVs have single speed* and have to operate over a wide speed range, albeit the speed range for most is less than half that of F1. If F1 reduced to 4 speed that would provide a challenge for the motor and controller electronics which might spill over to the road.

Personally I think the ICEs would sound better as well but that’s very subjective.

*Porsche use 2 speed on the Taycan are they only volume manufacturer to do so?
Am I right in thinking that CVT would allow the use of a heavier flywheel and more efficient transfer each way by self selecting the ratios, or is this just added complexity?
When arguing with a fool, be sure the other person is not doing the same thing.

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FW17
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Joined: 06 Jan 2010, 10:56

Re: 2025/2026 Hybrid Powerunit speculation

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What ever they are doing at the rear is uninteresting, but they should focus on MGU on the front ro regenerate and deploy.

Formula E with gen 3 will be doing front wheel regeneration and their car is still going to be lighter than F1.

Like I mentioned before F1 should move back to lighter V10 engines with an ERS H to recover exhaust energy

mzso
mzso
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Re: 2025/2026 Hybrid Powerunit speculation

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Big Tea wrote:
01 Mar 2021, 15:21
Am I right in thinking that CVT would allow the use of a heavier flywheel and more efficient transfer each way by self selecting the ratios, or is this just added complexity?
I don't think CVT is viable for F1 power levels.

J.A.W.
J.A.W.
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Re: 2025/2026 Hybrid Powerunit speculation

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mzso wrote:
02 Mar 2021, 06:44
Big Tea wrote:
01 Mar 2021, 15:21
Am I right in thinking that CVT would allow the use of a heavier flywheel and more efficient transfer each way by self selecting the ratios, or is this just added complexity?
I don't think CVT is viable for F1 power levels.
Actually it was tested (by Williams, AFAIR?) but since it both showed def' promise of being
advantageous (& sounded crappy, like a long, long, clutch slip), it was promptly banned.
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saviour stivala
saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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Does F1 engines use a flywheel, is the new power unit going to use a flywheel?.

mzso
mzso
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Re: 2025/2026 Hybrid Powerunit speculation

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J.A.W. wrote:
02 Mar 2021, 08:37
Actually it was tested (by Williams, AFAIR?) but since it both showed def' promise of being
advantageous (& sounded crappy, like a long, long, clutch slip), it was promptly banned.
I know, I also heard it was unreliable and didn't last long.

Jolle
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Re: 2025/2026 Hybrid Powerunit speculation

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saviour stivala wrote:
02 Mar 2021, 08:42
Does F1 engines use a flywheel, is the new power unit going to use a flywheel?.
Racing engines have as light flywheel as they can get away with. The MGUK gives the possibility to have a virtual flywheel,
Making the ICE both responsive on itself and can idle at low revs.

saviour stivala
saviour stivala
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Re: 2025/2026 Hybrid Powerunit speculation

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I believe that all 4 power units mounts the clutch including the release/engage mechanism in the gearbox and that they use as stub-shaft between internally splined crankshaft output end and clutch basket. They use no flywheel.

Tommy Cookers
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Re: 2025/2026 Hybrid Powerunit speculation

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Jolle wrote:
02 Mar 2021, 12:13
... The MGUK gives the possibility to have a virtual flywheel,
Making the ICE both responsive on itself and can idle at low revs.
current 'virtual flywheel' potential ?

(ok the ICE 'external flywheel' is only the clutch driving plate(s) - the clutch body on the gearbox input shaft this century)
and/but the MGU-K/geartrain inertia is (relative to the ICE's) multiplied by the square of the geartrain ratio
and the ICE cycle torque 'response' is faster than the MGU-K's - plus the ICE's torque much greater than the K's

ie the ICE dominates (and the K parasitises) the PU torque cycle

the K is too 'weak' to smooth the cycle .... but ....
yes intelligent use of the MGU-K could eg dampen driveline oscillations and somewhat reduce their frequency


yes if for 2025/6 the ICE is halved and the K trebled some things will be different (some worse)
eg gearshift quality would be degraded as the new K will have more inertia and a slower response
and in principle oscillations could be caused by the K
Last edited by Tommy Cookers on 02 Mar 2021, 15:52, edited 1 time in total.

Jolle
Jolle
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Re: 2025/2026 Hybrid Powerunit speculation

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Tommy Cookers wrote:
02 Mar 2021, 15:30
Jolle wrote:
02 Mar 2021, 12:13
... The MGUK gives the possibility to have a virtual flywheel,
Making the ICE both responsive on itself and can idle at low revs.
current 'virtual flywheel' potential ?

(ok the ICE 'external flywheel' is only the clutch driving plate(s) - the clutch body on the gearbox input shaft this century)
and/but the MGU-K/geartrain inertia is multiplied by the square of the geartrain ratio
and the ICE cycle torque 'response' is faster than the MGU-K's - plus the ICE's torque much greater than the K's

ie the ICE dominates the PU torque cycle - ie K is too 'weak' to smooth it

yes intelligent use of the MGU-K could eg dampen driveline oscillations and somewhat reduce their frequency


yes if for 2025/6 the ICE is halved and the K trebled some things will be different
but eg gearshift quality would be degraded as the new K will have more inertia and a slower response
The whole drivetrain has more then enough mass to smoothen out the bangs at high rpm, no need for an extra few kg of spinning mass like in road engines. The only problem then is low rpm and idle. Where the engine doesn't have enough inertia to keep running smooth (and why non hybrid racing engines have to idle at 3000-5000 rpm). The power and torque at 2000 rpm is very low, so having it "helped" by a 160hp electric motor isn't a problem.

mzso
mzso
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Re: 2025/2026 Hybrid Powerunit speculation

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What is the average power of an F1 car for a lap?
I don't think I ever saw a number for this. With series hybrids or fuel cells it would be the most relevant value to design for.