2025/2026 Hybrid Powerunit speculation

[gruntguru]

I've seen his comments but I'm quite skeptical of some of the things he says.

a, How are you going to recover any significant amount of energy in partial throttle conditions when your ICE is 350kW and max regen is 350kW? If you want full regen you will have no propulsion. If you take less than full regen the end power at the rear wheels will be so low there can't be many partial throttle corners where this is actually useful for any real length of time. . . .

I'm sure you will find a lot of track time where wheel-power required is less than 350 kW (all braking and lots of cornering). All of this time is "genset" re-charging opportunity. Remember there is very little braking where 350 kW can be harvested from the rear axle - this can be topped up to 350 kW using the genset.

We're not talking about braking, we're talking partial throttle. Getting perfect regen under braking is a pre-requisite to make this even remotely work, and it's still not close to enough, which is why he made the partial throttle argument.

I don't think you will find much regen in partial throttle zones for the reasons I outlined. You need 3x more regen and your combustion engine is 40% less powerful. F1 tracks are like 70% full throttle, 10% and a bit braking. And that's with 800-1000HP engines. Imagine you have 500HP, how much partial throttle do you really think we're gonna have? The cars would have to be ridiculously slow for there to be a lot of partial throttle with a 500HP ICE. And for the very limited time you have partial throttle you obviously won't get the full 350kW, but a limited amount based on the power demand at the rear wheels.

So using your numbers and lets assume there is enough fuel to generate to the max 350kW wherever possible (yes I know there isn't enough). The ICE runs at 350kW for 90% of the lap. For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels). During braking (10% of the lap) there is 350 kW going to the ES.

So total storage is:
Laptime x [(350 x 20% x 1/2) + (350 x 10%)] = Laptime x 70 kW

The average power available for the remaining 70% is therefore
350 + (Laptime x 70)/(Laptime x 70%) = 450kW

Of course the stored energy would be deployed in bursts with output power varying from 350 - 700 kW during that 70% of the lap.

[gruntguru]

The numbers I used, a change of 0.15 Cd was near 20hp at 190mph.

Sounds low. Have you missed a zero somewhere?

[Zynerji]

So even if the ice would be allowed to deliver full power under braking, to let the MGU-K generate, there isn’t enough fuel, because then the ICE would be at full power a whole lap. Never enough for more than 20-30% full throttle with ERS deployment.

It really means downshifting down the straight, or the drag must become 0 on the straight.

It's a good probability of yet another train wreck.

[Hoffman900]

The numbers I used, a change of 0.15 Cd was near 20hp at 190mph.

Sounds low. Have you missed a zero somewhere?

I was going off memory, so probably.

[vorticism]

So even if the ice would be allowed to deliver full power under braking, to let the MGU-K generate...

Powered braking would be loud braking. Interesting. WOT sound while the car zooms by into the corner.

Well, we're losing 300-500HP at top speed, so unless you plan on shedding so much drag it becomes a low drag roadcar, I'm not holding out hope. And like I said, even with active aero, this is an open-wheel formula car, it's always going to be relatively draggy.

Overall speed is also more important than top speed, which is why weight and big HP matter. Acceleration is king.

As far as F1 is from its traditional features currently, wheel fairings would not be out of place. Just be forwarned, everyone. Newey designed the Gran Turismo X cars... 13 years ago.

[Cs98]

So using your numbers and lets assume there is enough fuel to generate to the max 350kW wherever possible (yes I know there isn't enough). The ICE runs at 350kW for 90% of the lap. For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels). During braking (10% of the lap) there is 350 kW going to the ES.

So total storage is:
Laptime x [(350 x 20% x 1/2) + (350 x 10%)] = Laptime x 70 kW

The average power available for the remaining 70% is therefore
350 + (Laptime x 70)/(Laptime x 70%) = 450kW

Of course the stored energy would be deployed in bursts with output power varying from 350 - 700 kW during that 70% of the lap.

" For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels)."

Sounds like an ambitious estimate but let's assume they can make that work. That would basically mean the 350kW MGU-K will give you less average deployment over the lap than the 120kW MGU-K we currently have (assuming no shenanigans with lift and coast and running it as a generator). Which just strikes me as an utter failure of the regs. We need to be getting more regen to make this 50/50 split work, instead we're going to get less on most tracks. Dual axle regen and/or exhaust regen is the only way to make it efficient enough to work, and we have neither.

[vorticism]

They could go heavy on rear weight bias (although the published regs afaik make no mention of this). 70:30. 80:20?

[gruntguru]

So using your numbers and lets assume there is enough fuel to generate to the max 350kW wherever possible (yes I know there isn't enough). The ICE runs at 350kW for 90% of the lap. For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels). During braking (10% of the lap) there is 350 kW going to the ES.

So total storage is:
Laptime x [(350 x 20% x 1/2) + (350 x 10%)] = Laptime x 70 kW

The average power available for the remaining 70% is therefore
350 + (Laptime x 70)/(Laptime x 70%) = 450kW

Of course the stored energy would be deployed in bursts with output power varying from 350 - 700 kW during that 70% of the lap.

" For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels)."

Sounds like an ambitious estimate but let's assume they can make that work. That would basically mean the 350kW MGU-K will give you less average deployment over the lap than the 120kW MGU-K we currently have (assuming no shenanigans with lift and coast and running it as a generator). Which just strikes me as an utter failure of the regs. We need to be getting more regen to make this 50/50 split work, instead we're going to get less on most tracks. Dual axle regen and/or exhaust regen is the only way to make it efficient enough to work, and we have neither.

Don't forget - that 20% is not all the cornering - just the cornering that doesn't require all 350 kW.

assuming no shenanigans with lift and coast and running it as a generator

I was assuming running it as a generator for as much of the lap as possible.

[wuzak]

They could go heavy on rear weight bias (although the published regs afaik make no mention of this). 70:30. 80:20?

If they reduce the wheelbase then the weight bias would move further to the rear.

[Stu]

They could go heavy on rear weight bias (although the published regs afaik make no mention of this). 70:30. 80:20?

http://1.bp.blogspot.com/-KtdCQKGXUWs/V ... 2A7560.jpg

https://www.carscoops.com/wp-content/up ... 25255d.jpg

The Delta-wing would be an interesting avenue; the core of the concept being half the mass, half the drag, half the power.

If that thought process was built into the regulations (reasonably easy with an ‘unachievable’ minimum weight of 500kg & a maximum fuel capacity of 60 litres), power unit capacity would no longer need to be stipulated (but could be limited by a maximum value). Maintaining the ES & MGU-K masses as they are stipulated in the 2026 PU regs would drive designs down the route of smaller, lighter (therefore more nimble), cleaner (aerodynamically & environmentally) cars.

[wuzak]

So using your numbers and lets assume there is enough fuel to generate to the max 350kW wherever possible (yes I know there isn't enough). The ICE runs at 350kW for 90% of the lap. For 20% (cornering) lets say half goes to the ES (the other half needed to drive the wheels). During braking (10% of the lap) there is 350 kW going to the ES.

So total storage is:
Laptime x [(350 x 20% x 1/2) + (350 x 10%)] = Laptime x 70 kW

The average power available for the remaining 70% is therefore
350 + (Laptime x 70)/(Laptime x 70%) = 450kW

Of course the stored energy would be deployed in bursts with output power varying from 350 - 700 kW during that 70% of the lap.

I think 20% of the lap requiring less than 350kW is optimistic.

It would be funny to se an F1 car go around Lowes Hairpin at Monaco at 50 or 60km/h with the ICE at WOT and the MGUK recovering energy.

[mzso]

Doomsaying talk prior to every rule change in formula 1 was always the norm. RB agreed and signed off on the new power unit formula. Their talk - 'Having to change gear down before end of straight' is political. Their real problem is the CHASSIS RULES are still up in the air. From its start the new formula was engine dominated and everybody went - 'this is dumb', now-a-days it became chassis dominated, and for those dominating it is great while it lasts, but are now feeling unsure if they would still be able to produce a dominant chassis in 2026, so they start push-out politics to maneuvers things around. Running out of battery power at some long end of straights is not going to be a new thing as it is there nowadays. Normally it is compensated for by adjustment of how much full battery deployment after corner exit tappers off once car reaches full speed, but this adjustment depends on how good the car aero efficiency is.

If any team can be confident of delivering a top rate chassis it's Red Bull. They've been consistently doing it for many years.

cceleration is king.

As far as F1 is from its traditional features currently, wheel fairings would not be out of place. Just be forwarned, everyone. Newey designed the Gran Turismo X cars... 13 years ago.

By "designed" you mean vaguely specified some attributes that felt right to him.

[mzso]

I feel like teams will rue them voting down the PU proposal for 2021 years before.

They could go heavy on rear weight bias (although the published regs afaik make no mention of this). 70:30. 80:20?

http://1.bp.blogspot.com/-KtdCQKGXUWs/V ... 2A7560.jpg

https://www.carscoops.com/wp-content/up ... 25255d.jpg

But would it help much when during braking most of the load shifts to the front?

[mzso]

The Delta-wing would be an interesting avenue; the core of the concept being half the mass, half the drag, half the power.

If that thought process was built into the regulations (reasonably easy with an ‘unachievable’ minimum weight of 500kg & a maximum fuel capacity of 60 litres), power unit capacity would no longer need to be stipulated (but could be limited by a maximum value). Maintaining the ES & MGU-K masses as they are stipulated in the 2026 PU regs would drive designs down the route of smaller, lighter (therefore more nimble), cleaner (aerodynamically & environmentally) cars.

Such freedom has become very alien to F1.

[wuzak]

Christian Horner:
“Obviously one of the biggest weight additions as well is the cell weight. The size of the battery is colossal for these 2026 regs.”

https://www.autosport.com/f1/news/why-h ... /10491959/

Why does he keep saying that? The SOC requirements have not changed, so one would expect the cells to be the same as specified for the current regulations - that is, between 20kg and 25kg.

Addition items are included in the ES minimum weight of 35kg.

From 2022 rules:

ENERGY STORE (ES)
The difference between the maximum and minimum state of charge of the ES may not exceed 4MJ at any time the car is on track.

5.5.3 The total mass of the part of the ES that stores energy, i.e. the cells (including any clamping plates) and electrical connections between cells, must be no less than 20kg and must not exceed 25kg.

From the 2026 rules:

5.4.8 The difference between the maximum and the minimum state of charge of the ES may not exceed 4MJ at any time the car is on the track.

5.19.9 The minimum mass for the ES Main Enclosure and the elements residing inside of it (articles 5.19.7 and 5.19. is 35.0kg. The procedure which will be used to determine this value may be found in the Appendix to the Technical and Sporting Regulations.

The referenced articles:

5.19.7 The following elements of the power unit must be fitted inside the ES main enclosure and be installed within the ERS reference volume:
a. ES elements as defined in items 26 (ES) and 29 (HV elements) of Appendix 3 to these regulations.
b. The HV safety elements and sensors defined in items 27 (DC sensor, IMD) and 28 (safety devices) of Appendix 3 to these regulations.
c. Any DC-DC converter and its connection to the ES HV DC bus. Includes active parts, enclosure, brackets and supports.
d. CU-K. Includes active parts, enclosure, brackets and supports.
e. HV DC connections between ES and CU-K/DC-DC converter. Includes all conductors, insulation, EMC screening, mechanical and thermal shielding.

5.19.8 In addition to the components listed in Article 5.19.7, the following elements may also be fitted within the ES main enclosure:
a. Low voltage Power Distribution Board (PDB).
b. PU Electric pump Driver units.
c. Low Voltage systems passive protection devices - Fuse box.
d. Low Voltage looms exclusively used: for PU functionalities or power supply chassis devices.
e. Any Electronic Box devices exclusively used for PU functionalities.
With the exception of wiring or any mechanical supports for these components, no additional elements may be fitted in the ES main enclosure.


So why would the battery be heavier? Bigger CE?