2025/2026 Hybrid Powerunit speculation

[DenBommer]

Ok, thanks for clarifying this

[wuzak]

If F1 is stuck with combustion, the most efficient would be a gas turbine generator with electric drive motors, imho.

My concept was to simplify and minimize that machine to the limit.

Small turbines tend to not be that efficient.

Roughly they are talking about 48% thermal efficiency for 2026 ICE (3000MJ/hr, target 400kW).

Small turbine efficiencies are much less than that.

[wuzak]

Maybe a stupid question, but if I'm correct is the RDE+turbo+MGUK a turbo generators on itself?

My idea was to put the rde between the impeller shell and the exducer shell (where the current turbo designs use a cartridge bearing), with the MGUH connected to the shaft on the impeller end. Something like 600V/300A because of high RPM that would drive electric motors front and rear. In this setup, there would be no battery (maybe small ultracap array for electric hysteresis). As driver demands torque, RPM of the gas generator changes to deliver more amperage. Pretty simple imho.

The best way to use the turbine in that case is to run it at constant speed (thereby maximising efficiency) and have the electric motor controller respond to the driver's input.

The turbine would not provide the peak output of the system, but a lower power figure, with a battery, or some kind of storage, providing the extra power when demanded, and storing the excess when the turbine is providing more than required.

[Zynerji]

Maybe a stupid question, but if I'm correct is the RDE+turbo+MGUK a turbo generators on itself?

My idea was to put the rde between the impeller shell and the exducer shell (where the current turbo designs use a cartridge bearing), with the MGUH connected to the shaft on the impeller end. Something like 600V/300A because of high RPM that would drive electric motors front and rear. In this setup, there would be no battery (maybe small ultracap array for electric hysteresis). As driver demands torque, RPM of the gas generator changes to deliver more amperage. Pretty simple imho.

The best way to use the turbine in that case is to run it at constant speed (thereby maximising efficiency) and have the electric motor controller respond to the driver's input.

The turbine would not provide the peak output of the system, but a lower power figure, with a battery, or some kind of storage, providing the extra power when demanded, and storing the excess when the turbine is providing more than required.

That's what I meant by a hysteresis battery.

[vorticism]

RB-Ford latest update: https://racingnews365.com/exclusive-hor ... owertrains

"Initially it was going to be a four-cylinder engine and a very different architecture, so it would have been a clean sheet for everybody. Whereas, basically, what we've ended up with is a current engine without the H [MGU-H] and a bigger battery.

"So that gives the incumbents a significant carryover advantage, which we are obviously pedalling hard to catch up."

First I've heard that the teams or FIA were considering a four cylinder for 2025/6.

[AR3-GP]

RB-Ford latest update: https://racingnews365.com/exclusive-hor ... owertrains

"Initially it was going to be a four-cylinder engine and a very different architecture, so it would have been a clean sheet for everybody. Whereas, basically, what we've ended up with is a current engine without the H [MGU-H] and a bigger battery.

"So that gives the incumbents a significant carryover advantage, which we are obviously pedalling hard to catch up."

First I've heard that the teams or FIA were considering a four cylinder for 2025/6.

The irony is that Porsche was competing in the WEC from 2014-2018 with a turbocharged V4....

The discussions were happening at a time when F1 was trying to get Porsche to join....and claimed to reset so that no one had a carry over advantage...despite Porsche having years of experience with a V4, MGU-H and MGU-K

[vorticism]

Honestly, Porsche's approach to motorsport seems the most intelligent sometimes.

[wuzak]

How much impact on the PU design will the chassis regulations have?

The 2026 regulations state:

5.20.3 All mechanical power to and from the MGU-K must pass through a single shaft to the MGU-K transmission. The connection to the ICE crankshaft must be ahead of XPU=100.

The MGUK could be tucked up under one bank of the engine, or it could be positioned ahead of the engine.

With the new regulations possibly reducing car dimensions, the wheelbase could be cut by as much as 600mm, maybe more.

This would shift the weight balance rearwards, which would require narrower front tyres, relative to the rear, than now, or the teams would have to find ways to shift the weight forward, such as moving the MGUK ahead of the ICE (MGUK is ~8.7% of PU total mass).

[Bill]

RB-Ford latest update: https://racingnews365.com/exclusive-hor ... owertrains

First I've heard that the teams or FIA were considering a four cylinder for 2025/6.

The irony is that Porsche was competing in the WEC from 2014-2018 with a turbocharged V4....

The discussions were happening at a time when F1 was trying to get Porsche to join....and claimed to reset so that no one had a carry over advantage...despite Porsche having years of experience with a V4, MGU-H and MGU-K

IS not an mguh is just an electrical machine that produce electricity using gases from exhaust pipes.mguh is much much more than that and more complex and expensive.

[mzso]

My idea was to put the rde between the impeller shell and the exducer shell (where the current turbo designs use a cartridge bearing), with the MGUH connected to the shaft on the impeller end. Something like 600V/300A because of high RPM that would drive electric motors front and rear. In this setup, there would be no battery (maybe small ultracap array for electric hysteresis). As driver demands torque, RPM of the gas generator changes to deliver more amperage. Pretty simple imho.

The best way to use the turbine in that case is to run it at constant speed (thereby maximising efficiency) and have the electric motor controller respond to the driver's input.

The turbine would not provide the peak output of the system, but a lower power figure, with a battery, or some kind of storage, providing the extra power when demanded, and storing the excess when the turbine is providing more than required.

That's what I meant by a hysteresis battery.

Well, it wasn't clear at all.

But I still fail to see how it could be efficient, if we assume it could work at all (a very big if).
You have the RDE to generate thrust with its efficiency being less than the carnot limit, which you don't use for propulsion at all. Then you have a detonations, extreme supersonic airflow spikes that somehow drives a turbine for which the carnot limit applies a second time. And then the generator. And you have some fancy transmission that connects the turbine spinning at 50k-100k RPM with the wheels. It's unclear whether you imagined a separate traction motor besides this.

[mzso]

Honestly, Porsche's approach to motorsport seems the most intelligent sometimes.

In what way?

[mzso]

First I've heard that the teams or FIA were considering a four cylinder for 2025/6.

The irony is that Porsche was competing in the WEC from 2014-2018 with a turbocharged V4....

The discussions were happening at a time when F1 was trying to get Porsche to join....and claimed to reset so that no one had a carry over advantage...despite Porsche having years of experience with a V4, MGU-H and MGU-K

IS not an mguh is just an electrical machine that produce electricity using gases from exhaust pipes.mguh is much much more than that and more complex and expensive.

That's pretty much what the MGU-H is. A dumb motor on the turbo shaft. The only addition is that it can act as a motor and spin up the turbine, which is trivial.

[Zynerji]

The irony is that Porsche was competing in the WEC from 2014-2018 with a turbocharged V4....

The discussions were happening at a time when F1 was trying to get Porsche to join....and claimed to reset so that no one had a carry over advantage...despite Porsche having years of experience with a V4, MGU-H and MGU-K

IS not an mguh is just an electrical machine that produce electricity using gases from exhaust pipes.mguh is much much more than that and more complex and expensive.

That's pretty much what the MGU-H is. A dumb motor on the turbo shaft. The only addition is that it can act as a motor and spin up the turbine, which is trivial.

I think the complexities lay in the windings and the control strategy. The hardware seems pretty common.

[Bill]

IS not an mguh is just an electrical machine that produce electricity using gases from exhaust pipes.mguh is much much more than that and more complex and expensive.

That's pretty much what the MGU-H is. A dumb motor on the turbo shaft. The only addition is that it can act as a motor and spin up the turbine, which is trivial.

I think the complexities lay in the windings and the control strategy. The hardware seems pretty common.

no is not a dumb motor ,it can spin over 200000 rpm and work at a excess temperature of over 1000 degree celcius,it can recover energy ,deploy energy and work to overcome turbo lag .in a nutshell it work in extreme conditions which need high level knowledge in material science and big budget.a jet engine is just a big shaft with lots fans ,a rocket engine is just a hallow tube that burn rocket fuel but we all know is not that simply.

[Zynerji]

That's pretty much what the MGU-H is. A dumb motor on the turbo shaft. The only addition is that it can act as a motor and spin up the turbine, which is trivial.

I think the complexities lay in the windings and the control strategy. The hardware seems pretty common.

no is not a dumb motor ,it can spin over 200000 rpm and work at a excess temperature of over 1000 degree celcius,it can recover energy ,deploy energy and work to overcome turbo lag .in a nutshell it work in extreme conditions which need high level knowledge in material science and big budget.a jet engine is just a big shaft with lots fans ,a rocket engine is just a hallow tube that burn rocket fuel but we all know is not that simply.

Not impressed. Not at all. Fluid bearings, investment casting water jackets, Tesla cars open patents for best asynchronous motors of all time.

It's about the assembly, optimization of windings, and tuning the "harmonics" of the M->G->M control strategy.

The 2014 units while not as powerful as today's units would still be beneficial from a spec unit perspective, and probably way less expensive.