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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Juzh
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Joined: 06 Oct 2012, 08:45

Re: 2025/2026 Hybrid Powerunit speculation

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wuzak wrote:
30 Jun 2025, 18:46
Hey wuzak, have you noticed this update to engine regs (post from reddit highlighting PU changes)
https://old.reddit.com/r/formula1/comme ... erational/
There is a limit on energy harvesting of 8.5Mj per lap. At some events this may be reduced to 8Mj where the FIA determines that you can't really harvest more than 8Mj per lap.
This limit may be further reduced to no less than 5MJ for Sprint Qualifying and Qualifying sessions at Competitions where the FIA determines that the harvesting strategies required to achieve the above limit are excessive, subject to the conditions specified in Article B7.2.

Also:

There is a total power reduction limit of 450kW maximum and the resulting electrical DC power of the ERS-K must remain above -100kW(i.e. 350kW deployment to 100kW harvest = 450kW power reduction)
These limits are changed respectively to 600kW and -250kW for the Sprint Qualifying and Qualifying sessions.
So more regen will be allowed in quali, but not during the race. I expect this is because -250kw is a serious amount of decel while under full throttle and it could be seen as a sort of brake check and potentially dangerous.

wuzak
wuzak
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Joined: 30 Aug 2011, 03:26

Re: 2025/2026 Hybrid Powerunit speculation

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Juzh wrote:
08 Jul 2025, 23:17
wuzak wrote:
30 Jun 2025, 18:46
Hey wuzak, have you noticed this update to engine regs (post from reddit highlighting PU changes)
https://old.reddit.com/r/formula1/comme ... erational/
There is a limit on energy harvesting of 8.5Mj per lap. At some events this may be reduced to 8Mj where the FIA determines that you can't really harvest more than 8Mj per lap.
This limit may be further reduced to no less than 5MJ for Sprint Qualifying and Qualifying sessions at Competitions where the FIA determines that the harvesting strategies required to achieve the above limit are excessive, subject to the conditions specified in Article B7.2.

Also:

There is a total power reduction limit of 450kW maximum and the resulting electrical DC power of the ERS-K must remain above -100kW(i.e. 350kW deployment to 100kW harvest = 450kW power reduction)
These limits are changed respectively to 600kW and -250kW for the Sprint Qualifying and Qualifying sessions.
So more regen will be allowed in quali, but not during the race. I expect this is because -250kw is a serious amount of decel while under full throttle and it could be seen as a sort of brake check and potentially dangerous.
No, I hadn't seen that.

It seems like a stupid change.

It's going to make the difference between qualifying and race performance even greater.

NL_Fer
NL_Fer
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Joined: 15 Jun 2014, 09:48

Re: 2025/2026 Hybrid Powerunit speculation

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Is anything known about how much mapping is allowed for the hybrid system? I mean if they can disable the electric deployment for curvy medium speed parts of the track, that might as well be traction control. The driver will have only ICE power available and be less prone to spinning the rear.

Hoffman900
Hoffman900
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Joined: 13 Oct 2019, 03:02

Re: 2025/2026 Hybrid Powerunit speculation

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NL_Fer wrote:
10 Jul 2025, 11:58
Is anything known about how much mapping is allowed for the hybrid system? I mean if they can disable the electric deployment for curvy medium speed parts of the track, that might as well be traction control. The driver will have only ICE power available and be less prone to spinning the rear.
Yes.

All co-authored with Ferrari and open source to download:

Model-Based Pre-Ignition Diagnostics in a Race Car Application

https://www.mdpi.com/1996-1073/12/12/2277
Abstract

Since 2014, Formula 1 engines have been turbocharged spark-ignited engines. In this scenario, the maximum engine power available in full-load conditions can be achieved only by optimizing combustion phasing within the cycle, i.e., by advancing the center of combustion until the limit established by the occurrence of abnormal combustion. High in-cylinder pressure peaks and the possible occurrence of knocking combustion significantly increase the heat transfer to the walls and might generate hot spots inside the combustion chamber. This work presents a methodology suitable to properly diagnose and control the occurrence of pre-ignition events that emanate from hot spots. The methodology is based on a control-oriented model of the ignition delay, which is compared to the actual ignition delay calculated from the real-time processing of the in-cylinder pressure trace. When the measured ignition delay becomes significantly smaller than that modeled, it means that ignition has been activated by a hot spot instead of the spark plug. In this case, the presented approach, implemented in the electronic control unit (ECU) that manages the whole hybrid power unit, detects a pre-ignition event and corrects the injection pattern to avoid the occurrence of further abnormal combustion.
Time-Optimal Low-Level Control and Gearshift Strategies for the Formula 1 Hybrid Electric Powertrain

https://www.mdpi.com/1996-1073/14/1/171
Abstract

Today, Formula 1 race cars are equipped with complex hybrid electric powertrains that display significant cross-couplings between the internal combustion engine and the electrical energy recovery system. Given that a large number of these phenomena are strongly engine-speed dependent, not only the energy management but also the gearshift strategy significantly influence the achievable lap time for a given fuel and battery budget. Therefore, in this paper we propose a detailed low-level mathematical model of the Formula 1 powertrain suited for numerical optimization, and solve the time-optimal control problem in a computationally efficient way. First, we describe the powertrain dynamics by means of first principle modeling approaches and neural network techniques, with a strong focus on the low-level actuation of the internal combustion engine and its coupling with the energy recovery system. Next, we relax the integer decision variable related to the gearbox by applying outer convexification and solve the resulting optimization problem. Our results show that the energy consumption budgets not only influence the fuel mass flow and electric boosting operation, but also the gearshift strategy and the low-level engine operation, e.g., the intake manifold pressure evolution, the air-to-fuel ratio or the turbine waste-gate position.
Low-level Online Control of the Formula 1 Power Unit with Feedforward Cylinder Deactivation


https://arxiv.org/abs/2303.00372
Since 2014, the Fédération Internationale de l'Automobile has prescribed a parallel hybrid powertrain for the Formula 1 race cars. The complex low-level interactions between the thermal and the electrical part represent a non-trivial and challenging system to be controlled online. We present a novel controller architecture composed of a supervisory controller for the energy management, a feedforward cylinder deactivation controller, and a track region-dependent low-level nonlinear model predictive controller to optimize the engine actuators. Except for the nonlinear model predictive controller, the proposed controller subsystems are computationally inexpensive and are real time capable. The framework is tested and validated in a simulation environment for several realistic scenarios disturbed by driver actions or grip conditions on the track. In particular, we analyze how the control architecture deals with an unexpected gearshift trajectory during an acceleration phase. Further, we demonstrate how an increased maximum velocity trajectory impacts the online low-level controller. Our results show a suboptimality over an entire lap with respect to the benchmark solution of 49 ms and 64 ms, respectively, which we deem acceptable. Compared to the same control architecture with full knowledge of the disturbances, the suboptimality amounted to only 2 ms and 17 ms. For all case studies we show that the cylinder deactivation capability decreases the suboptimality by 7 to 8 ms.

gruntguru
gruntguru
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Joined: 21 Feb 2009, 07:43

Re: 2025/2026 Hybrid Powerunit speculation

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NL_Fer wrote:
10 Jul 2025, 11:58
Is anything known about how much mapping is allowed for the hybrid system? I mean if they can disable the electric deployment for curvy medium speed parts of the track, that might as well be traction control. The driver will have only ICE power available and be less prone to spinning the rear.
Nothing like traction control. Suppose you gave the driver a switch that cuts power by 50%. That's nothing like traction control.
je suis charlie

vorticism
vorticism
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Joined: 01 Mar 2022, 20:20

Re: 2025/2026 Hybrid Powerunit speculation

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Juzh wrote:
08 Jul 2025, 23:17
So more regen will be allowed in quali, but not during the race. I expect this is because -250kw is a serious amount of decel while under full throttle and it could be seen as a sort of brake check and potentially dangerous.
Quali specific braking. Big if true. Unlocked by turning three of the eighteen dials on the steering wheel to a specific position. We're doing the sustainability, please clap.

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Zynerji
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Joined: 27 Jan 2016, 16:14

Re: 2025/2026 Hybrid Powerunit speculation

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This entire Formula will go down in history as the worst idea ever.

The times in 2025 are the closest of all-time. Why, oh, why not delay these new regs until 2027-8?!?!

wuzak
wuzak
474
Joined: 30 Aug 2011, 03:26

Re: 2025/2026 Hybrid Powerunit speculation

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Zynerji wrote:
12 Jul 2025, 00:44
This entire Formula will go down in history as the worst idea ever.

The times in 2025 are the closest of all-time. Why, oh, why not delay these new regs until 2027-8?!?!
It's complicated by Audi taking over Sauber with their own PU, and Cadillac entering.

I wonder how the current PUs compare with the 2026 PU in simulations of the 2026 chassis.

mzso
mzso
67
Joined: 05 Apr 2014, 14:52

Re: 2025/2026 Hybrid Powerunit speculation

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Zynerji wrote:
12 Jul 2025, 00:44
This entire Formula will go down in history as the worst idea ever.

The times in 2025 are the closest of all-time. Why, oh, why not delay these new regs until 2027-8?!?!
What would be the point. It wouldn't be better in 28. If it will suck as much as everyone expects it will be rid of it as soon as possible. MBS is already talking about three years for the engine reg.

vorticism
vorticism
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Joined: 01 Mar 2022, 20:20

Re: 2025/2026 Hybrid Powerunit speculation

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Stroll has already tested Aston Martin’s interpretation of the rules in the team’s simulator. He isn’t happy next year’s cars will have a lower overall downforce level as a result of the power unit changes.

“It’s just a bit of a shame we’re just – Formula 1’s just – taking that path of electric energy and we’ve had to shed all the downforce off the cars to support the battery power,” he said. “It should be fun to see some light, nimble, fast cars with a lot of downforce and just simplify the whole thing a little bit. Less so of an energy, battery, championship, science project and more of just a Formula 1 racing championship.”

Stroll claimed some of his rival drivers share his concerns but are unwilling to criticise next year’s rules package.

“I’m not a fan of the direction but if we have a fast car and we’re competitive and we are doing better than everyone else, that’s when you’ve got nothing to complain about,” he said. “I don’t love the idea of the regs though.

“I think a lot of the drivers can agree on that. Maybe some of them can’t talk about it for political reasons. I think it’s exciting to think about cars that can scream a little bit louder, be a bit lighter, and not depend and focus so much on that energy, battery powertrain that’s not very racy,” Stroll added.

Other drivers who have spoken about next year’s regulations, such as Max Verstappen, have voiced concerns that the energy regeneration, management and deployment may come to dominate the racing. “I don’t know if that’s racing,” said Stroll.

“But it’s going to be the same for everyone next year and it’s all going to about who can do that best. I’m sure whoever’s doing that best is going to love the new regs.”
https://www.racefans.net/2025/07/12/man ... ns-stroll/