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.
Tommy Cookers
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Joined: 17 Feb 2012, 16:55

Re: 2025/2026 Hybrid Powerunit speculation

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Jolle wrote:
25 Dec 2021, 00:23
.... As long as 70% throttle is 70% torque, it doesn’t matter that it’s 60% ICE + 10% K or 80% ICE and -10% K.
With a good electric motor and well written software/control unit, it must be smoother/directer then a V12 without flywheel.
regardless of what attributes the FIA classes as TC and what attributes the FIA doesn't call TC .....

inertia in an ICE tends to resist wheel spin (and underrotation) - so high inertia ie a flywheel might seem useful.. but ..
low inertia ie 'without flywheel' is chosen to avoid slowing gearshifts and lowering crankshaft resonant frequency

nevertheless the F1 ICE has inertia and the MGU-K inertia adds more inertia
a much larger eg 300 kW MGU-K will add a further inertia (and the PU will be slower to accelerate/decelerate itself)
the ICE's ability to accelerate/decelerate itself is always better than an MGU-K's ability to accelerate/decelerate itself

so regardless of the FIA the 2025/6 PU will have more inherent resistance to wheelspin (and locking)

mapping had already in the NA days regulations that ....
restricted the rate of torque reduction (with rpm eg during wheel spin) demanded by the software functionality

the current and future systems reproduce these restrictions ... but ....
fundamentally the actual torque changes can't comply during sudden high-rate-of-change events eg wheelspin
this (dynamic response) 'time constant' of the PU will be at least c.100 msec
ie for 100 msec the PU is acting for the driver more than the regulations seem to allow

also the dynamic response of the K machine etc could be designed to give further hidden benefits

CMSMJ1
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Location: Chesterfield, United Kingdom

Re: 2025/2026 Hybrid Powerunit speculation

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ENGINE TUNER wrote:
23 Dec 2021, 23:21
mzso wrote:
23 Dec 2021, 21:00
ENGINE TUNER wrote:
22 Dec 2021, 21:17
What they should do is freeze the current engine blocks and mguh (lease one to VAG if necessary), double mguk output, switch to 100% biofuel(waste derived), allow rotary or freevalve tech, allow plasma ignition, or any other cutting edge add-ons that boost efficiency.
Sounds complicated. Just slap on an engine development cost cap, a maximum power output, a bio fuel. And allow anything within.
Nothing complicated about freezing the engine blocks and mguh, but yeah, an engine cost cap and open development of top end and ignition. But F1 should never ever have a maximum power output, its bad enough that the mguk is strictly limited.

F1 also needs a rule that they can only harvest when fully off the torque demand pedal.
I think this is a great idea for improving the racing - or a limit on how much throttle they have - i.e cannot harvest on a full throttle.
IMPERATOR REX ANGLORUM

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henry
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Location: England

Re: 2025/2026 Hybrid Powerunit speculation

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CMSMJ1 wrote:
05 Jan 2022, 18:29
ENGINE TUNER wrote:
23 Dec 2021, 23:21
mzso wrote:
23 Dec 2021, 21:00


Sounds complicated. Just slap on an engine development cost cap, a maximum power output, a bio fuel. And allow anything within.
Nothing complicated about freezing the engine blocks and mguh, but yeah, an engine cost cap and open development of top end and ignition. But F1 should never ever have a maximum power output, its bad enough that the mguk is strictly limited.

F1 also needs a rule that they can only harvest when fully off the torque demand pedal.
I think this is a great idea for improving the racing - or a limit on how much throttle they have - i.e cannot harvest on a full throttle.
It depends what you mean by “cannot harvest”. If you mean from the K, then I don’t think it’s common for them to harvest from the K at full throttle. If they harvest from the K they must also harvest from the H. That puts harvest at around 190/200 kW but power to the road at ICE power - 120kW. Ferrari used to do this.

At full throttle they usually harvest from the H at the end of straights. If they didn’t do this they might do more lift and coast. Most people are not keen on lift and coast.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

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henry
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Joined: 23 Feb 2004, 20:49
Location: England

Re: 2025/2026 Hybrid Powerunit speculation

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henry wrote:
05 Jan 2022, 19:29
CMSMJ1 wrote:
05 Jan 2022, 18:29
ENGINE TUNER wrote:
23 Dec 2021, 23:21


Nothing complicated about freezing the engine blocks and mguh, but yeah, an engine cost cap and open development of top end and ignition. But F1 should never ever have a maximum power output, its bad enough that the mguk is strictly limited.

F1 also needs a rule that they can only harvest when fully off the torque demand pedal.
I think this is a great idea for improving the racing - or a limit on how much throttle they have - i.e cannot harvest on a full throttle.
Edit. Ignore my response it doesn’t apply if there’s no H.

It depends what you mean by “cannot harvest”. If you mean from the K, then I don’t think it’s common for them to harvest from the K at full throttle. If they harvest from the K they must also harvest from the H. That puts harvest at around 190/200 kW but power to the road at ICE power - 120kW. Ferrari used to do this.

At full throttle they usually harvest from the H at the end of straights. If they didn’t do this they might do more lift and coast. Most people are not keen on lift and coast.
Fortune favours the prepared; she has no favourites and takes no sides.
Truth is confirmed by inspection and delay; falsehood by haste and uncertainty : Tacitus

CMSMJ1
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Joined: 25 Sep 2007, 10:51
Location: Chesterfield, United Kingdom

Re: 2025/2026 Hybrid Powerunit speculation

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henry wrote:
05 Jan 2022, 19:32
henry wrote:
05 Jan 2022, 19:29
CMSMJ1 wrote:
05 Jan 2022, 18:29


I think this is a great idea for improving the racing - or a limit on how much throttle they have - i.e cannot harvest on a full throttle.
Edit. Ignore my response it doesn’t apply if there’s no H.

It depends what you mean by “cannot harvest”. If you mean from the K, then I don’t think it’s common for them to harvest from the K at full throttle. If they harvest from the K they must also harvest from the H. That puts harvest at around 190/200 kW but power to the road at ICE power - 120kW. Ferrari used to do this.

At full throttle they usually harvest from the H at the end of straights. If they didn’t do this they might do more lift and coast. Most people are not keen on lift and coast.
Absolutely - you're quite right. Oh well, the horse has bolted on that one.
IMPERATOR REX ANGLORUM

mzso
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Joined: 05 Apr 2014, 14:52

Re: 2025/2026 Hybrid Powerunit speculation

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CMSMJ1 wrote:
06 Jan 2022, 11:30
Absolutely - you're quite right. Oh well, the horse has bolted on that one.
But as he corrected, it doesn't apply when there's no H, which as far as we know is what's going to be the case.

I see little other chance for them to fill the increased storage, than running the engine at full power whenever they can on normally not full throttle parts. (Though I guess it will/would be really confusing for the drivers.)

Pat Pending
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Joined: 22 Feb 2016, 13:11

Re: 2025/2026 Hybrid Powerunit speculation

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mzso wrote:
06 Jan 2022, 13:48
I see little other chance for them to fill the increased storage, than running the engine at full power whenever they can on normally not full throttle parts
How is that possible without slipping the clutch (a lot)?

Tommy Cookers
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Joined: 17 Feb 2012, 16:55

Re: 2025/2026 Hybrid Powerunit speculation

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Pat Pending wrote:
06 Jan 2022, 13:52
mzso wrote:
06 Jan 2022, 13:48
I see little other chance for them to fill the increased storage, than running the engine at full power whenever they can on normally not full throttle parts
How is that possible without slipping the clutch (a lot)?
the back wheels only see the power that the driver wants them to see

the generation torque is fully variable according to the wishes moment-by-moment of the control electronics CE
and if the generation torque is programmed to be a predictable/learnable fraction of the ICE torque .....
neither the driver nor the back wheels care what fraction of the ICE power is taken by GU-K action

if drivers can work the DRS they can work this
what's not to like ?

this is the inevitable consequence of upsizing the MGU-K towards parity with the ICE
at some point will lose the 8-speed discrete gearing applied to both the ICE and (ICE-slaved) MGU-K
and progress to hybrid-style transmission ie the MG varying the mixing of the ICE and MG

2 MGs might be best .... even allowing some ....
integrated short-term (flywheel ?) energy storage

mzso
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Joined: 05 Apr 2014, 14:52

Re: 2025/2026 Hybrid Powerunit speculation

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Pat Pending wrote:
06 Jan 2022, 13:52
mzso wrote:
06 Jan 2022, 13:48
I see little other chance for them to fill the increased storage, than running the engine at full power whenever they can on normally not full throttle parts
How is that possible without slipping the clutch (a lot)?
Well, the K is connected to the crankshaft, so the clutch doesn't come into play.
Tommy Cookers wrote:
06 Jan 2022, 14:02
and if the generation torque is programmed to be a predictable/learnable fraction of the ICE torque .....
neither the driver nor the back wheels care what fraction of the ICE power is taken by GU-K action
I don't think it would be easily predictable, not that it would matter much as long as the driver gets a consistent power/torque output by the press of the pedal.
The noise, vibrations would be out of place, and contrary to drivers' intuitions. The ice powering up without pedal input an such. It might be a bit of a pain to learn to ignore it.

Jolle
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Joined: 29 Jan 2014, 22:58
Location: Dordrecht

Re: 2025/2026 Hybrid Powerunit speculation

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Tommy Cookers wrote:
25 Dec 2021, 14:08
Jolle wrote:
25 Dec 2021, 00:23
.... As long as 70% throttle is 70% torque, it doesn’t matter that it’s 60% ICE + 10% K or 80% ICE and -10% K.
With a good electric motor and well written software/control unit, it must be smoother/directer then a V12 without flywheel.
regardless of what attributes the FIA classes as TC and what attributes the FIA doesn't call TC .....

inertia in an ICE tends to resist wheel spin (and underrotation) - so high inertia ie a flywheel might seem useful.. but ..
low inertia ie 'without flywheel' is chosen to avoid slowing gearshifts and lowering crankshaft resonant frequency

nevertheless the F1 ICE has inertia and the MGU-K inertia adds more inertia
a much larger eg 300 kW MGU-K will add a further inertia (and the PU will be slower to accelerate/decelerate itself)
the ICE's ability to accelerate/decelerate itself is always better than an MGU-K's ability to accelerate/decelerate itself

so regardless of the FIA the 2025/6 PU will have more inherent resistance to wheelspin (and locking)

mapping had already in the NA days regulations that ....
restricted the rate of torque reduction (with rpm eg during wheel spin) demanded by the software functionality

the current and future systems reproduce these restrictions ... but ....
fundamentally the actual torque changes can't comply during sudden high-rate-of-change events eg wheelspin
this (dynamic response) 'time constant' of the PU will be at least c.100 msec
ie for 100 msec the PU is acting for the driver more than the regulations seem to allow

also the dynamic response of the K machine etc could be designed to give further hidden benefits
I presume that inertia, in the form of a big flywheel, limits wheels spin because the engine can't rise in RPM so fast that you'll have snap oversteer (for instance) but, the downside is that the engine is also far less responsive and will be slower (the better the driver, the less inertia he will use, the faster he will go, etc etc)

The possibilities of a electrical motor in line with the ICE is that you can simulate a flywheel and inertia (when you want) or simulate even an ICE with less inertia that it actually has. For instance: in wet weather: big flywheel on throttle, small flywheel off throttle (to quickly stop spinning wheels), etc etc.

As long as the driver is the only input, I don't see a problem with these kinds of drive modes. It's like an "engine braking +" setting.

mzso
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Joined: 05 Apr 2014, 14:52

Re: 2025/2026 Hybrid Powerunit speculation

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Tommy Cookers wrote:
25 Dec 2021, 14:08
nevertheless the F1 ICE has inertia and the MGU-K inertia adds more inertia
a much larger eg 300 kW MGU-K will add a further inertia
But the MGU is not dead weight. It can add or take away energy at will.

How do you fi
Tommy Cookers wrote:
25 Dec 2021, 14:08
(and the PU will be slower to accelerate/decelerate itself)
the ICE's ability to accelerate/decelerate itself is always better than an MGU-K's ability to accelerate/decelerate itself
How do you figure this? This can't be right. ICE's can't even decelerate itself. And MGU can decelerate by the same amount of power as it can accelerate. Even besides this (for acceleration) it can go to full power a lot quicker than an ICE, as well as being able to provide max torque in a much wider range.

I don't get what you're trying to say.

Pat Pending
3
Joined: 22 Feb 2016, 13:11

Re: 2025/2026 Hybrid Powerunit speculation

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mzso wrote:
06 Jan 2022, 14:54
Well, the K is connected to the crankshaft, so the clutch doesn't come into play.
That's kinda my point - you can't run the engine at (near) constant rpm to drive the MGU AND slow the car at the same time (without a CVT). Or put another way MGU rpm = ICE rpm = gearbox input shaft rpm.

Sorry if I'm being particularly dense here. I'm not trying to be difficult, just don't understand what you're getting at ;o)

Tommy Cookers
617
Joined: 17 Feb 2012, 16:55

Re: 2025/2026 Hybrid Powerunit speculation

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Pat Pending wrote:
06 Jan 2022, 17:31
... you can't run the engine at (near) constant rpm to drive the MGU AND slow the car at the same time (without a CVT). Or put another way MGU rpm = ICE rpm = gearbox input shaft rpm.
well they downshift through successive gears to keep the rpm around the famous 10500
judging by the Honda telemetry

that rpm isn't vital for generation but it is preferable and so used where available
probably the K isn't designed for much higher current (that would be needed for 120 kW at much lower rpm)

Tommy Cookers
617
Joined: 17 Feb 2012, 16:55

Re: 2025/2026 Hybrid Powerunit speculation

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mzso wrote:
06 Jan 2022, 17:06
Tommy Cookers wrote:
25 Dec 2021, 14:08
nevertheless the F1 ICE has inertia and the MGU-K inertia adds more inertia
a much larger eg 300 kW MGU-K will add a further inertia
But the MGU is not dead weight. It can add or take away energy at will.
Tommy Cookers wrote:
25 Dec 2021, 14:08
(and the PU will be slower to accelerate/decelerate itself)
the ICE's ability to accelerate/decelerate itself is always better than an MGU-K's ability to accelerate/decelerate itself
How do you figure this? This can't be right. ICE's can't even decelerate itself. And MGU can decelerate by the same amount of power as it can accelerate. Even besides this (for acceleration) it can go to full power a lot quicker than an ICE, as well as being able to provide max torque in a much wider range.
the MGU IS 'dead weight' ... insofar as ....

it can't add or take away (mechanical) energy except within accelerations limited by its own inertia ... ie ....
its torque can change in c.2 msec - (the 'electrical time constant') if that torque change doesn't go into rpm change
but otherwise there will be no torque (eg output) unless rate-of-change demanded is much slower eg 20 msec
this torque-going-into-rpm-change response time can be called the 'electro-mechanical time constant'

the (NA anyway) F1 ICE has a torque-change-going-into-rpm-change 'response time' of less than 10 msec
(shown in Honda's paper on in-shift modulation of clutch transmitted torque - and Renault's 'Marseillaise' sound demo)
far better than the response time of the MGU-K

yes I have designed electro-mechanical servo systems

mzso
59
Joined: 05 Apr 2014, 14:52

Re: 2025/2026 Hybrid Powerunit speculation

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Pat Pending wrote:
06 Jan 2022, 17:31
mzso wrote:
06 Jan 2022, 14:54
Well, the K is connected to the crankshaft, so the clutch doesn't come into play.
That's kinda my point - you can't run the engine at (near) constant rpm to drive the MGU AND slow the car at the same time (without a CVT). Or put another way MGU rpm = ICE rpm = gearbox input shaft rpm.

Sorry if I'm being particularly dense here. I'm not trying to be difficult, just don't understand what you're getting at ;o)
I didn't say the engine would run at near constant RPM. Nor did I speak about slowing at the same time. Where'd you come up with it? You responded to this:
I see little other chance for them to fill the increased storage, than running the engine at full power whenever they can on normally not full throttle parts. (Though I guess it will/would be really confusing for the drivers.)

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