2025/2026 Hybrid Powerunit speculation

[saviour stivala]

The FIA introduced (for 2026) track dependent energy rules for the new hybrid power unit to insure safety and maintain race quality. These rules are to prevent excessive speeds on certain tracks and will manage the power deployment, with specific restrictions planed for circuits like Monaco and singapore where speeds will be lower, ''Speed based power tapering'': Regulations will gradually reduce the electric power as cars reach higher speeds (above 300 km/h) to control top speeds. ''Managed energy reduction'': There are limits on how quickly the power can be reduced to prevent sudden dangereuse drops in performanced. ''Focus on efficiency'': The rules are designed to prevent a situation where drivers have to lift off the throttle on straights to conserve energy, ensuring a more consistent and high quality racing experience. From the above, one can see that ''Driver power demand/ full throttle'' The driver have control on ICE power deployed as demanded, But he have no control on the electrical part of the power output added to the crankshaft.

1. The accelerator pedal will change both ICE and MGU-K output.
2. The brake pedal will change MGU-K output.
3. The driver can change mode switch settings which will change MGU-K output and its relationship to the accelerator pedal.

When the driver is demanding full power (100% throttle - throttle pedal to the floor) and the electrical power contribution to crankshaft starts tapering-off, the electrical part of the power contribution to crankshaft has slipped out of driver control (not under driver control as per his demand). Here is another 'tapering-off of electrical power contribution to the crankshaft which will not be under driver control as per his demand. It is called ''MOM mode'' with another effective tapering - off of electrical power contribution. The system is activated by the driver manually when within a certain distance of car in front. This power boost provide the driver with a temporary, manual override of the power unit to deploy 350 kw of electric energy. This boost is available up to a certain speed, approximately 337 km/h, before tapering -off.

[diffuser]

I saw that all the PU Manufacturers are all investing in DeepDrive. DeepDrive are starting to manufacture a dual rotor electric motor. Thier electric motor's yoke is replaced by a 2nd rotor. It reduces the amount of magnetic material weight and cost. Wonder if they'll be using that in the MGU-K?

[Tommy Cookers]

I saw that all the PU Manufacturers are all investing in DeepDrive. DeepDrive are starting to manufacture a dual rotor electric motor. Thier electric motor's yoke is replaced by a 2nd rotor. It reduces the amount of magnetic material weight and cost. Wonder if they'll be using that in the MGU-K?

is that all the F1 PUs ?

an axial flux (ie disc-shaped) machine has inherently inferior response as the inertia is relatively greater
the F1 ideal is a PU response of a few milliseconds - or lap-time losses could accumulate with each up-shift
EDITED for 2026 the K machine has more influence (than before) over the 'upshift-lazy' ICE so shifts are presumably ok

yes of course the more future F1 is to resemble EVs the more attractive the DD etc approach will become
this might explain the alternative MGU-K locations now allowed

[diffuser]

I saw that all the PU Manufacturers are all investing in DeepDrive. DeepDrive are starting to manufacture a dual rotor electric motor. Thier electric motor's yoke is replaced by a 2nd rotor. It reduces the amount of magnetic material weight and cost. Wonder if they'll be using that in the MGU-K?

is that all the F1 PUs ?

an axial flux (ie disc-shaped) machine has inherently inferior response as the inertia is relatively greater
F1 needs a PU response of a few milliseconds - otherwise lap-time losses will accumulate with each shift

yes of course the more future F1 is to resemble EVs the more attractive the DD etc approach will become

Sorry, yes all F1 PU Manufacturers.

[vorticism]

I saw that all the PU Manufacturers are all investing in DeepDrive. DeepDrive are starting to manufacture a dual rotor electric motor. Thier electric motor's yoke is replaced by a 2nd rotor. It reduces the amount of magnetic material weight and cost. Wonder if they'll be using that in the MGU-K?

is that all the F1 PUs ?

an axial flux (ie disc-shaped) machine has inherently inferior response as the inertia is relatively greater
F1 needs a PU response of a few milliseconds - otherwise lap-time losses will accumulate with each shift

yes of course the more future F1 is to resemble EVs the more attractive the DD etc approach will become

DeepDrive's is a radial flux motor with two rotors spinning coaxially about a shared, sandwiched stator winding. Twice the rotor-stator surface interface area. Brilliant power-densifying design. I had toyed around with a similar design once but was then reminded of the time-honored engineering tradition: Germans already thought of it.

[FW17]

An high torque ultra light motor

[gruntguru]

The windings can only be supported at one end due to the dual rotor design. Their triangulated copper windings self-support under magnetic loads - brilliant.

[saviour stivala]

The choice of MGU-K motor is driven by the need to minimize weight and packaging size. The current axial flux design is more compact and lightweight solution that fits the overall design requirements of the car. The formula 1 manufacturers do not use the radial flux twin rotor motor for the MGU-K due to a combination of existing design constraints, the physical demands of the current axial flux configuration. specifically, the MGU-K placement at the front of the engine to connect to the crankshaft is more practical and lightweight.

[Tommy Cookers]

... The current axial flux design is more compact and lightweight solution that fits the overall design requirements of the car.
The formula 1 manufacturers do not use the radial flux twin rotor motor for the MGU-K due to a combination of existing design constraints, the physical demands of the current axial flux configuration. specifically, the MGU-K placement at the front of the engine to connect to the crankshaft is more practical and lightweight.

"the current axial flux design is ... "
so the 2014-2025 (ie 120 kW) MGU-K is axial flux ??

I expect an axial flux MG machine to be disc-shaped (pizza) and a radial flux machine to be cylinder-shaped (salami)
regardless of the flux orientation, the DeepDrive machine is rather disc-shaped
a disc-shaped machine will have more rotational inertia (and translational inertia ie 'weight' is unimportant)
so more energy will be required for acceleration - and more energy is stored in the rotation (think 60000 rpm)
(and the bigger MG helps the 2026 PU to be better suited to upshifting than the 2014-2025 PU)

as filling and emptying this energy store doesn't depend on tyre grip ...
perhaps they will mass-garnish the rotating parts - and Pirelli could blend tungsten powder into the tyre rubber mix ?


btw the site that was linked regarding DD also has information on the Ferrari EV 'motor'
even covering fake engine noise and fake gear-shifts

[saviour stivala]

Looks like for 2026 the axial flux type is still the prefered choice of motor by the formula 1 manufacturers.

[saviour stivala]

I saw that all the PU Manufacturers are all investing in DeepDrive. DeepDrive are starting to manufacture a dual rotor electric motor. Thier electric motor's yoke is replaced by a 2nd rotor. It reduces the amount of magnetic material weight and cost. Wonder if they'll be using that in the MGU-K?

is that all the F1 PUs ?

an axial flux (ie disc-shaped) machine has inherently inferior response as the inertia is relatively greater
the F1 ideal is a PU response of a few milliseconds - or lap-time losses could accumulate with each up-shift
EDITED for 2026 the K machine has more influence (than before) over the 'upshift-lazy' ICE so shifts are presumably ok

yes of course the more future F1 is to resemble EVs the more attractive the DD etc approach will become
this might explain the alternative MGU-K locations now allowed

The MGU-K is mandated to be located in front of the engine, and so no alternative locations are permitted under the 2026 regulations.

[saviour stivala]

... The current axial flux design is more compact and lightweight solution that fits the overall design requirements of the car.
The formula 1 manufacturers do not use the radial flux twin rotor motor for the MGU-K due to a combination of existing design constraints, the physical demands of the current axial flux configuration. specifically, the MGU-K placement at the front of the engine to connect to the crankshaft is more practical and lightweight.

"the current axial flux design is ... "
so the 2014-2025 (ie 120 kW) MGU-K is axial flux ??

I expect an axial flux MG machine to be disc-shaped (pizza) and a radial flux machine to be cylinder-shaped (salami)
regardless of the flux orientation, the DeepDrive machine is rather disc-shaped
a disc-shaped machine will have more rotational inertia (and translational inertia ie 'weight' is unimportant)
so more energy will be required for acceleration - and more energy is stored in the rotation (think 60000 rpm)
(and the bigger MG helps the 2026 PU to be better suited to upshifting than the 2014-2025 PU)

as filling and emptying this energy store doesn't depend on tyre grip ...
perhaps they will mass-garnish the rotating parts - and Pirelli could blend tungsten powder into the tyre rubber mix ?


btw the site that was linked regarding DD also has information on the Ferrari EV 'motor'
even covering fake engine noise and fake gear-shifts

Yes, The MGU-K motor used by F1 manufacturers is an 'axial flux' type of motor. The 'axial flux' motor used as the MGU-K by the F1 manufacturers, can handle high power and torque while being more compact and lightweight than comparable 'radial flux' type of motor, which is crucial for performance in race cars.

[gruntguru]

Chat GPT?

Co=Pilot says:

"The current Formula 1 MGU-K uses a radial flux design, not axial flux.
Here’s why:

Radial flux machines (rotor inside, stator outside) are preferred in F1 because they offer:

Lower rotational inertia, which is critical for ultra-fast response times (milliseconds) during gear shifts and energy deployment.
Better cooling and packaging for high-speed operation (up to 50,000 rpm).


Axial flux machines (disc-shaped) are generally more compact and can have higher torque density, but they have greater rotational inertia, which makes them less suitable for F1 where rapid transient response is essential. This was explicitly noted in technical discussions: axial flux designs are considered inferior for F1 because they slow response and could cost lap time during shifts. [f1technical.net]

So, the MGU-K in F1 is a high-speed permanent magnet synchronous machine with a radial flux configuration."

[mzso]

Chat GPT?

Co=Pilot says:

"The current Formula 1 MGU-K uses a radial flux design, not axial flux.
Here’s why:

Radial flux machines (rotor inside, stator outside) are preferred in F1 because they offer:

Lower rotational inertia, which is critical for ultra-fast response times (milliseconds) during gear shifts and energy deployment.
Better cooling and packaging for high-speed operation (up to 50,000 rpm).


Axial flux machines (disc-shaped) are generally more compact and can have higher torque density, but they have greater rotational inertia, which makes them less suitable for F1 where rapid transient response is essential. This was explicitly noted in technical discussions: axial flux designs are considered inferior for F1 because they slow response and could cost lap time during shifts. [f1technical.net]

So, the MGU-K in F1 is a high-speed permanent magnet synchronous machine with a radial flux configuration."

What about transverse-flux motors? Would that layout bring any advantages?

[saviour stivala]

Chat GPT?

Co=Pilot says:

"The current Formula 1 MGU-K uses a radial flux design, not axial flux.
Here’s why:

Radial flux machines (rotor inside, stator outside) are preferred in F1 because they offer:

Lower rotational inertia, which is critical for ultra-fast response times (milliseconds) during gear shifts and energy deployment.
Better cooling and packaging for high-speed operation (up to 50,000 rpm).


Axial flux machines (disc-shaped) are generally more compact and can have higher torque density, but they have greater rotational inertia, which makes them less suitable for F1 where rapid transient response is essential. This was explicitly noted in technical discussions: axial flux designs are considered inferior for F1 because they slow response and could cost lap time during shifts. [f1technical.net]

So, the MGU-K in F1 is a high-speed permanent magnet synchronous machine with a radial flux configuration."

Yes. You are right and I was wrong in my quoting of the Formula 1 MGU-K motor flux direction, my quoting was unintentionally the other way round.