2025/2026 Hybrid Powerunit speculation

[Zynerji]

Does anyone know why the mguh is so expensive? It seems like a 125k rpm 3 phase motor wouldn't be an outrageously expensive item in 2021.

The teams should "work group" design a spec part after sharing notes, and let Magnetti Marelli build for the teams.

The issue is that the MGU-H isn't just the electric motor, but the also the turbocharger. And the problem with that is that every time you change something on the combustion you also have to adapt the turbocharger to it. That results in a lot of simulation and testing work and very small production numbers for each specification.
With the current rules it's possible that you simulate and test things for several months and then just build maybe a dozen MGU-H setups for a single specification and that was your whole production run.

Sounds like a turbo problem...

Those things still apply if you remove the MGU.

[henry]

Does anyone know why the mguh is so expensive? It seems like a 125k rpm 3 phase motor wouldn't be an outrageously expensive item in 2021.

The teams should "work group" design a spec part after sharing notes, and let Magnetti Marelli build for the teams.

The issue is that the MGU-H isn't just the electric motor, but the also the turbocharger. And the problem with that is that every time you change something on the combustion you also have to adapt the turbocharger to it. That results in a lot of simulation and testing work and very small production numbers for each specification.
With the current rules it's possible that you simulate and test things for several months and then just build maybe a dozen MGU-H setups for a single specification and that was your whole production run.

Sounds like a turbo problem...

Those things still apply if you remove the MGU.

No they don’t. You’re only trying to optimise the turbine compressor to create power from the ICE whereas with the MGU-H you’re trying to optimise that plus the extraction of excess energy. As @Dr. Acura says that involves lots of simulation and dynamometer work, including modelling every circuit and the balance of K and H that maximises performance at the majority of them.

[Dr. Acula]

Does anyone know why the mguh is so expensive? It seems like a 125k rpm 3 phase motor wouldn't be an outrageously expensive item in 2021.

The teams should "work group" design a spec part after sharing notes, and let Magnetti Marelli build for the teams.

The issue is that the MGU-H isn't just the electric motor, but the also the turbocharger. And the problem with that is that every time you change something on the combustion you also have to adapt the turbocharger to it. That results in a lot of simulation and testing work and very small production numbers for each specification.
With the current rules it's possible that you simulate and test things for several months and then just build maybe a dozen MGU-H setups for a single specification and that was your whole production run.

Sounds like a turbo problem...

Those things still apply if you remove the MGU.

Yes, but to a far lower degree. With the MGU-H you want to squeeze as much energy out of the exhaust gases as you can. Because as the rules are at the moment, energy flow from and to the MGU-H is unlimited. So the MGU-H is really a place where you can gain a lot without violating any rules. Also the turbocharger F1 uses at the moment are far to big for an engine with this displacement and rpm range to work well without the electric motor.
If you throw the MGU-H out, the focus goes more torward a turbocharger setup which reaches the desired boost pressure very quickly and then just keep it up. This is still not simple, but a lot easier to develope than what we have now because the turbo is no longer part of the energy recovery system as a whole. The gains of optimisation would be a lot smaller especially with the proposed more powerful electric systems.

[henry]

If you remove the MGU-H you reduce the number of potential power modes substantially. Currently there are potentially 9 combinations of ICE, K, H and ES that can be deployed to vary the combinations of power to the wheels and to and from the ES.

ICE + K + boost (K and compressor driven by ES, Electric supercharge)
ICE + K (K driven H and ES)
ICE + K (K driven by H)
ICE + k (K driven by ES via the H, theoretical only analogous to Honda extra Harvest)
ICE only
ICE - K (K and H charge ES , end of straight)
ICE only (H charges ES)
ICE - k (K charges ES via H, Honda extra harvest)
ice - k (K and H charge ES under part throttle)
- K (K charges ES during braking)

Honda have probably abandoned extra harvest and “extra power” hasn’t been observed, the part throttle fuel flow restrictions were aimed at restricting the part throttle mode.

Without the MGU-H there are only 4 possible modes.

ICE only
ICE + K (driven from ES)
ICE - K (part throttle ES charging)
-K (charging the ES under braking)

So abandoning the H reduces complexity, both physically, and logically, the engineers can’t spend time trying to harness the H in creative ways.

[wuzak]

Removing the MGUH also drastically reduces the energy recovered over a lap.

[Zynerji]

I'd argue the MGUH is THE single most roadcar relevant part of Formula 1.

[mzso]

I'd argue the MGUH is THE single most roadcar relevant part of Formula 1.

Okay, so do so then.

[FW17]

Removing the MGUH also drastically reduces the energy recovered over a lap.

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

[Dr. Acula]

I'd argue the MGUH is THE single most roadcar relevant part of Formula 1.

Actually it's the probably the least roadcar relevant part. What do you need to make the MGU-H work well? Full throttle conditions. What do you hardly use in a road car, especially in city driving? Full throttle.
What can make sense in a roadcar is an electrical supported turbocharger. But you will never get into the situation where you can win substantial amounts of energy out of the Turbocharger in a roadcar like it is done in F1.

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

Years ago Magnetti Marelli had published a slide which showed the energy recovered per lap from the 2 different systems. Depending on the track the MGU-H could recover from about 4 to almost up to 8MJ per lap, i think it was in 2016. Also don't forget that you don't get all the energy out from the fuel to the road. The ERS system is at least twice as efficient compared with simply burning fuel, which means you save at least twice the amount you stated.

[henry]

Removing the MGUH also drastically reduces the energy recovered over a lap.

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

It’s not the MGU-K that does the majority of the recovery it’s the MGU-H.

If we assume an average output from the H of 80kW for 80% of a 100sec lap that’s 6.4MJ. Over 60 laps that’s 384MJ. The turbocharged ICE might run at 40% efficiency so we need 960MJ of fuel which at 45MJ/kg is 21kg.

The H also allows when the energy is used to be different from when it is generated. So the cars run higher power at the beginning of the straight than the end which is more lap time efficient. So the straight ICE car will need to carry more fuel to compensate. That’s a tricky calculation so I’ll guess at 25kg as a nice round number.

I don’t think the MGU-H system adds anything like 12kg in comparison to a turbo only The K MG is 8kg (by regulation). The H is 2/3 the power and runs at twice the speed and it’s weight is not regulated. So perhaps 4kg. The H turbine is larger than needed to only drive the compressor so it will be a little heavier and the compressor might also be smaller because they won’t need as much mass flow from the exhaust. There are cables for a few more grams. Even if we assume 10kg the extra fuel will be 15kg. So still slower at the beginning of the race.

[garrett]

I wouldn't say it "fits" better for Formula Cars as Indy Car nowadays also have two chargers. The main reason for a hot Vee was the energy heat recovery system.

If you throw the MGU-H out, the focus goes more torward a turbocharger setup which reaches the desired boost pressure very quickly and then just keep it up. This is still not simple, but a lot easier to develope than what we have now because the turbo is no longer part of the energy recovery system as a whole.

And therefor a biturbo configuration could be a solution to follow. With simply anti-lag device.

[FW17]

Removing the MGUH also drastically reduces the energy recovered over a lap.

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

It’s not the MGU-K that does the majority of the recovery it’s the MGU-H.

If we assume an average output from the H of 80kW for 80% of a 100sec lap that’s 6.4MJ. Over 60 laps that’s 384MJ. The turbocharged ICE might run at 40% efficiency so we need 960MJ of fuel which at 45MJ/kg is 21kg.

The H also allows when the energy is used to be different from when it is generated. So the cars run higher power at the beginning of the straight than the end which is more lap time efficient. So the straight ICE car will need to carry more fuel to compensate. That’s a tricky calculation so I’ll guess at 25kg as a nice round number.

I don’t think the MGU-H system adds anything like 12kg in comparison to a turbo only The K MG is 8kg (by regulation). The H is 2/3 the power and runs at twice the speed and it’s weight is not regulated. So perhaps 4kg. The H turbine is larger than needed to only drive the compressor so it will be a little heavier and the compressor might also be smaller because they won’t need as much mass flow from the exhaust. There are cables for a few more grams. Even if we assume 10kg the extra fuel will be 15kg. So still slower at the beginning of the race.

I would assume that recovery would be done when on full throttle; the maximum I think is 70% a lap of full throttle in the calendar.
I would assume the avg laptime to be 80 seconds
I also doubt a 4kg MGUH exists, as lumps of copper are not light.

[henry]

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

It’s not the MGU-K that does the majority of the recovery it’s the MGU-H.

If we assume an average output from the H of 80kW for 80% of a 100sec lap that’s 6.4MJ. Over 60 laps that’s 384MJ. The turbocharged ICE might run at 40% efficiency so we need 960MJ of fuel which at 45MJ/kg is 21kg.

The H also allows when the energy is used to be different from when it is generated. So the cars run higher power at the beginning of the straight than the end which is more lap time efficient. So the straight ICE car will need to carry more fuel to compensate. That’s a tricky calculation so I’ll guess at 25kg as a nice round number.

I don’t think the MGU-H system adds anything like 12kg in comparison to a turbo only The K MG is 8kg (by regulation). The H is 2/3 the power and runs at twice the speed and it’s weight is not regulated. So perhaps 4kg. The H turbine is larger than needed to only drive the compressor so it will be a little heavier and the compressor might also be smaller because they won’t need as much mass flow from the exhaust. There are cables for a few more grams. Even if we assume 10kg the extra fuel will be 15kg. So still slower at the beginning of the race.

I would assume that recovery would be done when on full throttle; the maximum I think is 70% a lap of full throttle in the calendar.
I would assume the avg laptime to be 80 seconds

Apologies. I did this from my head and used easy numbers. If I look back at the last time I put the real numbers in a spreadsheet (2017) the numbers were 88 seconds average lap and 60% full throttle. Since then they’ve gone quicker, bigger tyres and more downforce. So I’d settle for 85 seconds and 70%. They also harvest from the H for some proportion of part throttle running so maybe 75% is a reasonable ballpark.

This changes the numbers to
H recovery per lap 4.76MJ
Fuel equivalent 260g/lap
Extra fuel per race 16kg. Plus fuel to compensate for lower power at the start of straights.

I also doubt a 4kg MGUH exists, as lumps of copper are not light.

Copper is indeed dense. But at lower power and higher speed there will be only be a need for less than half as much. But there is probably less opportunity for reduction in the casing, cooling etc. I still think the H will be nearer to 4kg than 8.

[wuzak]

I wouldn't say it "fits" better for Formula Cars as Indy Car nowadays also have two chargers. The main reason for a hot Vee was the energy heat recovery system.

The regulations specifically require the exhaust to exit to the outside of the banks, with the intakes in the vee.

So no hot vee.

In any case, the MGUH sits inside the vee, whether there is a split turbo or not.

[wuzak]

Removing the MGUH also drastically reduces the energy recovered over a lap.

Is it possible for you to quantify this with MJ loss per lap and the weight of fuel required to compensate it?


The MGUK is 120kw assuming it runs 70% of the lap on full recovery(a big assumption) it will generate 1.9kwh which is 6.72 MJ
This is equal to 20kg fuel through the race.

If we consider only 4 MJ recovery a lap (about 50%), the saving is 12kg a race.
12kg is not much considering the MGUH along with its associated components probably weighs more than that

The MGUK is limited to 120kW generation and only does that for a few seconds per lap, which depends on the track.

We calculated some numbers a few years ago that showed a track like Silverstone was probably not allowing 1MJ recovery per lap from the MGUK. Albert Park and Monza slightly more. Most were around the 1.5MJ range.

IIRC only Singapore came close to 2MJ per lap, the maximum amount of energy that could be recovered from the MGUK to the ES according to the regulations.

Since we did those calculations the downforce has been increased substantially, cornering speeds have increased and braking times reduced. In some corners braking is no longer required.

It is likely that the teams use all the allowed 4MJ per lap from ES to MGUK. Which means that the MGUH is responsible for 2/3 to 3/4 of that energy.

However, energy flow from the MGUH to and from the MGUK or to and from the ES is unregulated. So it is possible that the ERS provides more than 4MJ per lap to the MGUK.

With the cornering speeds up and less braking it is also likely that the MGUH is generating more, since it spends less time spooling the turbo and not much time where the turbine power equals the compressor power.