2025/2026 Hybrid Powerunit speculation

[johnny comelately]

Current LMh regulations? Unlimited.

Maximum power is 500kW (+/- 20kW for BOP) at 95% maximum rpm.

There is a power curve defined for power units. Power is defined for points from 55% to 102.5% of maximum rpm.

I meant electrical harvest.
, my apologies

200kW MGUK.

Thank you

[Cold Fussion]

Thanks. Does anyone know how much power the MGU-H typically puts back into the ES? I cant see it being a massive amount as this would have an effect on the turbo shaft speeds due to the recovery along it. It does say unlimited, but that's clearly not possible.

It's unlimited energy, but the MGU-H is limited to 120KW. If you go back through the old threads I think it's been theorised on this forum the MGU-H will do something in the range of 60-100KW in self sustaining mode.

[wuzak]

Thanks. Does anyone know how much power the MGU-H typically puts back into the ES? I cant see it being a massive amount as this would have an effect on the turbo shaft speeds due to the recovery along it. It does say unlimited, but that's clearly not possible.

It would appear to be at least 2MJ, given that the maximum recovered from MGUK is 2MJ and 4MJ of deployment is allowed.

The MGUH can also send power directly to the MGUK, and the amount of energy doing this is also unlimited.

When the lights flash on the rear of the car, the MGUK is no longer deploying. Energy from the MGUH is being stored instead of being sent to the MGUK, and maybe the MGUK goes into recovery mode also.

I do wonder if we will be seeing cars doing multiple out laps on qualifying sims to get battery charged up to allow for the most energy deployment throughout a lap. As Nork4 pointed out, you could do a max regen giving you 37.1seconds of energy deployment. Given most tracks thats still probably only 1/3 of a lap total deployment of 350kW.

I wonder if we will end up seeing ES with huge amounts of storage, unless there is a cap on how much they can store.

Can't. Maximum storage is 4MJ.

9MJ maximum recovery. Which is 25.7s at 350kW.

37.1s of deployment would require starting the lap with 4MJ of charge and recovering and deploying an extra 9MJ on that lap.

I am not sure this will be the fastest way.

Possibly the fastest will be starting with 4MJ and recovering brake energy (call it 5MJ, ~14s braking time), but not extra harvesting, which would give 25.7s of deployment on that lap.

Is there any rulings yet on whether you could potentially harvest energy from the front axle in replacement of smaller brakes? I can see there being another weight increase aswell with all this additional batteries and storage.

MGUK connected to ICE only.

[wuzak]

Thanks. Does anyone know how much power the MGU-H typically puts back into the ES? I cant see it being a massive amount as this would have an effect on the turbo shaft speeds due to the recovery along it. It does say unlimited, but that's clearly not possible.

It's unlimited energy, but the MGU-H is limited to 120KW. If you go back through the old threads I think it's been theorised on this forum the MGU-H will do something in the range of 60-100KW in self sustaining mode.

MGUH power is not regulated. It is naturally limited by how much the turbine can produce above the power required for the compressor.

MGUK power is limited to 120kW.

[henry]

Thanks. Does anyone know how much power the MGU-H typically puts back into the ES? I cant see it being a massive amount as this would have an effect on the turbo shaft speeds due to the recovery along it. It does say unlimited, but that's clearly not possible.

It would appear to be at least 2MJ, given that the maximum recovered from MGUK is 2MJ and 4MJ of deployment is allowed.

The MGUH can also send power directly to the MGUK, and the amount of energy doing this is also unlimited.

When the lights flash on the rear of the car, the MGUK is no longer deploying. Energy from the MGUH is being stored instead of being sent to the MGUK, and maybe the MGUK goes into recovery mode also.

I do wonder if we will be seeing cars doing multiple out laps on qualifying sims to get battery charged up to allow for the most energy deployment throughout a lap. As Nork4 pointed out, you could do a max regen giving you 37.1seconds of energy deployment. Given most tracks thats still probably only 1/3 of a lap total deployment of 350kW.

I wonder if we will end up seeing ES with huge amounts of storage, unless there is a cap on how much they can store.

Can't. Maximum storage is 4MJ.

9MJ maximum recovery. Which is 25.7s at 350kW.

37.1s of deployment would require starting the lap with 4MJ of charge and recovering and deploying an extra 9MJ on that lap.

I am not sure this will be the fastest way.

Possibly the fastest will be starting with 4MJ and recovering brake energy (call it 5MJ, ~14s braking time), but not extra harvesting, which would give 25.7s of deployment on that lap.

Is there any rulings yet on whether you could potentially harvest energy from the front axle in replacement of smaller brakes? I can see there being another weight increase aswell with all this additional batteries and storage.

MGUK connected to ICE only.

I doubt they will be able to recover 5 MJ by braking. 350kW will only be available down to about 200kph at which they will be traction limited. The only track at which they can currently get to 2MJ is Singapore and that’s lots of medium speed stops. (Currently they get 120kW down to 120kph)

So I think they may be looking at burning fuel to drive the K and get to 9KJ. But right now I can’t understand the logic of 9MJ capture but 4MJ SOC.

[vorticism]

Some highlights of the 2026 regs. Single turbo aligned to vehicle centerline, 4.8 bar MAP, no block spanning split turbo (max inner span 175mm), no variable trumpets, no VGT, definition of throttle "TBD."

5.5 Turbocharger
* 5.5.1  Pressure charging may only be affected by the use of a sole single stage, single sided compressor with a single inlet linked to a sole single stage exhaust turbine by a shaft assembly. The compressor blades must be attached to a common hub surface and all air entering the combustion chamber must pass through the single exducer of these blades. The shaft must be designed so as to ensure that the shaft assembly, the compressor and the turbine always rotate about a common axis and at the same angular velocity. The energy of the rotating parts of the turbocharger may not be transferrable to any other component. Only parts approved by the FIA Technical Department may be used. Subject for provision of the Article 17.3.5, the approval of the FIA Technical Department is conditional upon the PU manufacturer, intending to use such parts during a Championship season undertaking not to conclude any exclusivity agreement (see definition article 5.1.30) for the supply of such parts with the supplier of these parts. The approval request form must be sent by the PU Manufacturer to the FIA before the 1st of November of the preceding year. 

* 5.5.2  Engine inlet air pressure must be less than 4.8 barA at all times. The pressure of the air will be measured by an FIA approved and sealed sensor located in an FIA approved location situated in the engine inlet system. 

* 5.5.3  The axis of the turbocharger shaft must be parallel to Y=0, inboard of Y=25 and at an angle of 0 +/- 1 degree to X=axis. 

* 5.5.4  The total mass of the turbocharger (TC) must be no less than 12kg 

* 5.5.5  Referring to Drawing 4 of Appendix 2, the turbocharger compressor and turbine must satisfy 
the following dimensional constraints:
* The compressor exducer diameter (A) must lie between 100mm and 110mm 

* The compressor axial distance from the outside diameter of the inducer blade edge to rear plane of exducer, at its outer diameter (B) must lie between 37.5mm and 42.5mm 

* The turbine inducer diameter (C) must lie between 95mm and 105mm 

* The turbine axial distance from the outside diameter of the exducer blade edge to forward plane of inducer, at its outer diameter (D) must lie between 30mm and 35mm 

* The maximum distance between the rear of the compressor exducer and the front of the turbine inducer (E) will be 175mm 

* [Note: the values set in 5.5.5 could change before the end of 2022 with a simple majority vote] 

* 5.5.6  The rotational speed of the turbocharger may not exceed 150,000rpm. 

* 5.5.7  The compressor inlet must extend upstream of any part of any variable geometry device permitted by Article 5.9 (throttle)



* 5.9.1  With the exception of wastegates, variable geometry exhaust systems are not permitted. No form of variable geometry turbine (VGT) or variable nozzle turbine (VNT) or any device to adjust the gas throat section at the inlet to the turbine wheel is permitted.
* 5.9.2  Variable valve timing and variable valve lift profile systems are not permitted.
* 5.9.3  Moveable trumpets are not permitted, and any geometry conveying the air from the 
compressor outlet to the cylinder inlet must be fixed, except the throttles. 
[Note: definition for the throttle will be provided in due course: device that creates a variable restriction to the airflow without affecting the geometry of the ducts either side of it.]



Additions to ES safety:

* 5.22.8  A dousing port must be present which is easily accessible on the external bodywork and that ducts extinguishant to the ES Main Enclosure Cavity. The duct must have an internal area of 175mm^2. The port must be covered with only a ISO 7010 F001 sticker. 
[Note: Further discussion will take place to assess the benefit and the best way to implement such a solution] 

* 5.22.9  The ES main enclosure compartments must be equipped with gas evacuation port(s) which in case of cells venting or electronic components explosion prevents the ESME internal pressure to be higher than 4.0BarA. The gas must be evacuated to a safe location (e.g. downwards towards the floor). The venting system must be approved by the FIA Technical Department before the 1st of November of the preceding year. 
[Note: Further discussion will take place to assess the benefit and the best way to implement such a burst disk solution] 

* 5.22.10  The ES main enclosure must be equipped with a system which allows discharging the ES with an off-board system, without having to open the ES main enclosure at the circuit when there is a failure in one of the HV safety devices. 
[Note: Further discussion will take place to assess the benefit of such a solution] 

* 5.22.11  The ES main enclosure must satisfy a minimum fire protection equivalent of UL94 V0 for cells using liquid electrolytes. The procedure which will be used to verify the protection level may be found in the Appendix to the Technical and Sporting Regulations. 
[Note: Further discussion will take place to define the level of fire protection/fire retardancy capabilities will be required and how it will be assessed. If it will be based on the materials used or fire penetration test.]

edit- fixed boost claim per per TC below

[Tommy Cookers]

Some highlights of the 2026 regs.... 4.8 bar max boost .....

5.5 Turbocharger
* 5.5.2  Engine inlet air pressure must be less than 4.8 barA at all times. The pressure of the air will be measured by an FIA approved and sealed sensor located in an FIA approved location situated in the engine inlet system. ....

4.8 bar boost it isn't
4.8 bar absolute it is

[vorticism]

ES & MGUK energy use:

5.4.6 The electrical DC power of the ERS-K may not exceed 350kW.
5.4.7 Additionally, the electrical DC power of the ERS-K used to propel the car may not exceed:
• P(kW)=1850-5* car speed (kph) when the car speed is below 340kph
• 150kW when the car speed is equal to or above 340kph
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.
5.4.9 The energy harvested by the ERS-K in each lap must not exceed 9MJ.
This limit applies to the energy going out of the CU-K and going into the ES.
5.4.10 The maximum mechanical torque of the MGU-K may not exceed 500Nm. The torque will be referenced to the crankshaft speed and a fixed efficiency correction of 0.97 will be used to monitor the maximum MGU-K mechanical torque.
5.4.11 With the exception of cars starting or resuming the race from the pit lane, the MGU-K may only be used during a standing start once the car has reached 50km/h.
5.4.12 The amount of stored energy in any ES may not be increased by more than 100kJ whilst the car is stationary in the pit lane or garage during the Qualifying Session or during a Race pit stop.
5.4.13 ERS Policing
a. In order to verify that the energy and power requirements of the ERS are being respected, all cars must be fitted with two DC sensors which have been manufactured and calibrated by the FIA designated suppliers to specifications determined by the FIA. Those sensors may only be installed outside the sealed perimeter of any CE-PU and used as specified below:
One DC sensor must be connected to the ES high voltage negative DC pole to measure all electrical energy into and out of the energy store.
The other DC sensor must be connected to the CUK high voltage positive DC pole to measure all electrical energy and power into and out of the ERS-K.
The DC sensors voltage sense wire must be connected to the dedicated measurement point defined by the FIA Technical department.
b. Electrical energy may not flow between consumers without being directly measured by one of the two DC sensors, previously listed. This must be guaranteed by design and verifiable by inspection.
c. The design of the ERS and the installation of the two DC sensors must be approved by the FIA. A preliminary technical dossier must be submitted to the FIA before 21 July prior to the preceding year of the introduction.
d. An airgap of 1mm must be present between the CU-K and any other consumer fitted inside the ES main enclosure. The only links allowed are the elements of the HV DC bus, MGU-K AC cables, cooling system components, low voltage looms and connectors dedicated for communication lines, 12V power supply, interlock loop systems, temperature sensors, MGU position sensors and any other sensor used by the ERS-K.

350 kW available 0-300 kph
350 kW reducing to 150 kW from 300 to 340 kph and beyond

[johnny comelately]

On the turbo specs, the similar sized Garret with a compressor exducer diameter of 109mm has a horsepower rating between 825 and 1575.
And a pressure ratio up to about 5 still on the island.
It is what we used on the bike.
https://www.garrettmotion.com/racing-an ... 9r-gen-ii/

[gruntguru]

On the turbo specs, the similar sized Garret with a compressor exducer diameter of 109mm has a horsepower rating between 825 and 1575.
And a pressure ratio up to about 5 still on the island.
It is what we used on the bike.
https://www.garrettmotion.com/racing-an ... 9r-gen-ii/

The ratings normally assume a rich AFR that can utilise most of the oxygen. For a lean engine running lambda 2.0 the compressor would only be rated at about half the engine power.

[johnny comelately]

On the turbo specs, the similar sized Garret with a compressor exducer diameter of 109mm has a horsepower rating between 825 and 1575.
And a pressure ratio up to about 5 still on the island.
It is what we used on the bike.
https://www.garrettmotion.com/racing-an ... 9r-gen-ii/

The ratings normally assume a rich AFR that can utilise most of the oxygen. For a lean engine running lambda 2.0 the compressor would only be rated at about half the engine power.

It is interesting you mention lambda 2, as I was wondering that too with the new rules, but from what I know even 1.1 produces a very inconsistent firing result (with normal spark)
So if they stay at around 1.3...
I still have trouble reconciling 1600cc for the new fuel flow rules
the unknown is the fuel specifications and characteristics, mainly re knock.

[wuzak]

I still have trouble reconciling 1600cc for the new fuel flow rules

It is odd.

Reduce fuel flow by 30-40%, but maintain capacity and rpm requirements, including not having max flow until 10,500rpm.

And the "simplified" PU saves maybe 4 or 5kg compared to a current PU.

[AJI]

I still have trouble reconciling 1600cc for the new fuel flow rules

It is odd.

Reduce fuel flow by 30-40%, but maintain capacity and rpm requirements, including not having max flow until 10,500rpm.

And the "simplified" PU saves maybe 4 or 5kg compared to a current PU.

Yeah, I guess they're relying on the big MGUK to take up the power deficit, but as has been previously mentioned, how is all this extra energy being recovered? Maybe a GUH like the Porsche LMP1h engine is in negotiation? I see no VGT or VNT so just an old fashioned wastegate, however, a GUH could work?

[wuzak]

I still have trouble reconciling 1600cc for the new fuel flow rules

It is odd.

Reduce fuel flow by 30-40%, but maintain capacity and rpm requirements, including not having max flow until 10,500rpm.

And the "simplified" PU saves maybe 4 or 5kg compared to a current PU.

Yeah, I guess they're relying on the big MGUK to take up the power deficit, but as has been previously mentioned, how is all this extra energy being recovered? Maybe a GUH like the Porsche LMP1h engine is in negotiation? I see no VGT or VNT so just an old fashioned wastegate, however, a GUH could work?

No GUH or MGUH is in the rules, and I doubt it will be.

You are correct, no variable parameters in the turbine, compressor or intake runners. Not finalised yet are the rules surrounding the throttles.

[Juzh]

''Unlimited amount of energy transferred to the ES''. But what is the ES maximum SOC allowed. So goes to the unlimited to the K as regards to its allowed output per lap.

9 MJ recovery allowed.
Unlimited energy deployment.
Storage is maximum 4MJ (maximum SOC - minimum SOC)

Suppose they can recover that much (they can't obviously, but lets go with it), why so much more recovery than deployment (9 vs 4 MJ)