2025/2026 Hybrid Powerunit speculation

[mzso]

Would it be better, and easier, if MGUK deployment was limited to 150kW, and recovery to 350kW?

Sounds like a lot of unused energy going to waste.

Not really.

Get 150kW for 60s instead of 350kW for 25s.

Though the MGUK will likely deliver a range of power between 0 and 350kW, and mostly around ~150kW.

That's assuming 9MJ can be recovered per lap, which looks to be a tall order.

Might have been thinking backwards. (Not sure now)

Anyway with onlny 150kW that's a massive reduction in power. Around a third.

[wuzak]

Sounds like a lot of unused energy going to waste.

Not really.

Get 150kW for 60s instead of 350kW for 25s.

Though the MGUK will likely deliver a range of power between 0 and 350kW, and mostly around ~150kW.

That's assuming 9MJ can be recovered per lap, which looks to be a tall order.

Might have been thinking backwards. (Not sure now)

Anyway with onlny 150kW that's a massive reduction in power. Around a third.

If the ICE can deliver 450kW as Mark Hughes suggests, that would give 600kW, or 800hp.

That's a ~20% reduction in power from current PUs, but should be more than enough given the drag reduction sought for the 2026 cars.

It would also negate the possibility of a 1,000hp car coming up on a 600hp car.

[Tommy Cookers]

If the ICE can deliver 450kW as Mark Hughes suggests, that would give 600kW, or 800hp.
That's a ~20% reduction in power from current PUs, but should be more than enough given the drag reduction sought for the 2026 cars.
It would also negate the possibility of a 1,000hp car coming up on a 600hp car.

don't the fuel heat rate reduction and the MGU-H elimination amount to far more than a 20% reduction in ICE power ?

[wuzak]

If the ICE can deliver 450kW as Mark Hughes suggests, that would give 600kW, or 800hp.
That's a ~20% reduction in power from current PUs, but should be more than enough given the drag reduction sought for the 2026 cars.
It would also negate the possibility of a 1,000hp car coming up on a 600hp car.

don't the fuel heat rate reduction and the MGU-H elimination amount to far more than a 20% reduction in ICE power ?

My scenario is 20% reduction in combined maximum power, not ICE power.

ICE power is reduced by ~25% using Mark Hughes' power number (450kW vs ~600kW) and by ~33% by target power numbers (400kW vs ~600kW).

[mzso]

Do the motor regs have any meaning anymore? It's some hodge-podge, frankenstein nonsense.
They wanted front wheel recovery and go with less fuel, to keep the weight from increasing. The teams vetoed it. And then they were low in power so the fuel went back 100kg. It would be hilarious if it wasn't pathetic.

So what do the regulations accomplish? Getting inferior to what we have now? (Less efficient and more cumbersome) Change for change's sake?

I'm not one of noise-fetishists, but I think it will also succeed in getting them to cry yet again. With the engine sound being completely detached from delivered power, and the engine going at full power all through (some) turns.

I doubt the cost will plummet either. Instead of the H that's already figured out, now they have to perpetually optimize the ICE and the K to work together well. For the K to be able to generate from ICE power efficiently on loads and RPM when the ICE is not typically efficient.

[Cs98]

Do the motor regs have any meaning anymore? It's some hodge-podge, frankenstein nonsense.
They wanted front wheel recovery and go with less fuel, to keep the weight from increasing. The teams vetoed it. And then they were low in power so the fuel went back 100kg. It would be hilarious if it wasn't pathetic.

So what do the regulations accomplish? Getting inferior to what we have now? (Less efficient and more cumbersome) Change for change's sake?

I'm not one of noise-fetishists, but I think it will also succeed in getting them to cry yet again. With the engine sound being completely detached from delivered power, and the engine going at full power all through (some) turns.

I doubt the cost will plummet either. Instead of the H that's already figured out, now they have to perpetually optimize the ICE and the K to work together well. For the K to be able to generate from ICE power efficiently on loads and RPM when the ICE is not typically efficient.

They accomplish one thing and one thing only, the manufacturers get to boast about a 50/50 power split and increased electrification. For "road relevance". That's why they are so keen on this and so critical of anyone who questions the entertainment value in these regs. The irony is of course that they are just what you say, less efficient and more cumbersome. Instead of having over 50% thermal efficiency and regenerating exhaust heat (you know actual RE-generation), we are now going to be below 50% TE and using the ICE as an electrical generator to charge the battery. That's supposed to be progress? It's like a skit of the modern board room executive catering to ESG directives. That is pretending to do something whilst in fact doing nothing, or making it worse in this case.

[wuzak]

They wanted front wheel recovery and go with less fuel, to keep the weight from increasing.

I ask again, if the power of deployment is the same as the power of recovery, does having front wheel recovery make any difference?

Plus, it is likely that front wheel recovery would lead to a heavier car, not lighter.

[chaoticflounder]

Yes,

This is due to weight transfer on braking.

Front brakes are typically larger than rears for this reason. Technically it limits the harvesting rate (i.e. power) that the rear can recover due to friction limitations that translates to torque upper limits on the electric motors.

I don't have numbers for this, but I suspect at the 2026 regs, during full deceleration and full recovery, it could very well be close to not using the rear brakes at all. (This is just a qualitative guess intended to illustrate my point.)

Another example is the 2016 Porsche Le Mans Hyper Car that had a front mounted MGU-K and turbo MGU-H. Personally I think this is the cleverest solution as it would allow regen on the front and, I believe, regen on the rear through braking and back driving the engine and using the turbo / MGU-H as well ... a turbine ... to recover energy that way. Not certain how feasible this is. Would be curious is more people looked into it.

[wuzak]

Yes,

This is due to weight transfer on braking.

Front brakes are typically larger than rears for this reason. Technically it limits the harvesting rate (i.e. power) that the rear can recover due to friction limitations that translates to torque upper limits on the electric motors.

But if the maximum recovery is 350kW, and the deployment is 350kW, whether rear wheel or 4 wheel system, and the braking time is the same, the amount of deployment is the same.

Also, the recovery limit (9MJ per lap) would also be the same.

It would make sense if the front recovered (eg. at 200kW) but did not deploy, while the rear recovered and deployed (at 150kW).

If a track has 15s of braking that allows 350kW to be recovered at the rear wheels, how much extra will you get from front recovery? 3s extra? 5s extra.

If it was 5s extra then the total recovery would be 7MJ, leaving you 2MJ short. You will still have to burn fuel to get the rest. Not as much, but still a significant amount.

[Tommy Cookers]

.. But if the maximum recovery is 350kW, and the deployment is 350kW, whether rear wheel or 4 wheel system, and the braking time is the same, the amount of deployment is the same.

isn't the big point of 2 axle recovery to get a max recovery power much more than 350 kW ?
even if we don't/can't motor at more than 350 kW

the huge wheelbase helps recovery under these single MG rules - as weight transfer from the rear axle is less

[wuzak]

.. But if the maximum recovery is 350kW, and the deployment is 350kW, whether rear wheel or 4 wheel system, and the braking time is the same, the amount of deployment is the same.

isn't the big point of 2 axle recovery to get a max recovery power much more than 350 kW ?
even if we don't/can't motor at more than 350 kW

That's what I am trying to get at.

There isn't much benefit to 2 axle recovery unless that increases the power of recovery beyond that of the power of deployment.

In Formula E the maximum recovery is 600kW (250kW front, 350kW rear), while the maximum deployment is 350kW.

If 2 axle recovery with similar power to Formula E was allowed in F1, the car minimum weight would be even higher.

[AR3-GP]

.. But if the maximum recovery is 350kW, and the deployment is 350kW, whether rear wheel or 4 wheel system, and the braking time is the same, the amount of deployment is the same.

isn't the big point of 2 axle recovery to get a max recovery power much more than 350 kW ?
even if we don't/can't motor at more than 350 kW

the huge wheelbase helps recovery under these single MG rules - as weight transfer from the rear axle is less

The peak recovery limit is just a label. The actual average recovery power around a lap measured under any braking event is probably less than 350kw during the braking events because of only being able to recover on the rear axle and the limitation of partial braking (analogous to partial throttle).
.

Having the front axle recovery would still bring the average recovery power closer to 350Kw, because you would extract more energy during each braking event. Especially under light to moderate trail braking where the rear axle can't recover at 350kw because there isn't sufficient brake demand from the rear axle alone.

[mzso]

They wanted front wheel recovery and go with less fuel, to keep the weight from increasing.

I ask again, if the power of deployment is the same as the power of recovery, does having front wheel recovery make any difference?

Plus, it is likely that front wheel recovery would lead to a heavier car, not lighter.

Of course. They can't recover enough with just the rear, so they need to run the ICE against the MGU in recovery mode.
So more fuel burn. Withe the front wheel recovery they wouldn't need to mess with that.

[wuzak]

They wanted front wheel recovery and go with less fuel, to keep the weight from increasing.

I ask again, if the power of deployment is the same as the power of recovery, does having front wheel recovery make any difference?

Plus, it is likely that front wheel recovery would lead to a heavier car, not lighter.

Of course. They can't recover enough with just the rear, so they need to run the ICE against the MGU in recovery mode.
So more fuel burn. Withe the front wheel recovery they wouldn't need to mess with that.

Only if the front MGU doesn't deploy also.

[mzso]

I ask again, if the power of deployment is the same as the power of recovery, does having front wheel recovery make any difference?

Plus, it is likely that front wheel recovery would lead to a heavier car, not lighter.

Of course. They can't recover enough with just the rear, so they need to run the ICE against the MGU in recovery mode.
So more fuel burn. Withe the front wheel recovery they wouldn't need to mess with that.

Only if the front MGU doesn't deploy also.

Whether you deploy 350 kW on four or two wheels is not relevant.