2025/2026 Hybrid Powerunit speculation

[Blackout]

No matter the engine, please don't make it another V6, they all sound like vacuum cleaners. V4 would be more interesting in my opinion than a V6. V8-12 sound glorious but it's too many for this day and age.

Here's a thought, should F1 engines be longitudinally mounted? From an aero and other dynamics perspective it's the best, and most logical choice. Transversely mounted engines? Would it even be worth it? Such a wide engine plus gearbox would limit the coke bottle shape of the car.

The only upside to an inline engine is that it's relevant to what most people run in their cars. It's as long as a V8 and the bracing needed to make it a stressed member of the chassis will make it nearly as wide.

Flat-4 should be even more interesting :Phttps://www.f1technical.net/forum/viewtopic.php ... at#p951240

[NL_Fer]

I've got in touch with someone who attended the ImechE conference I've mentioned in the previous posts. Did not manage to get any of the presentations but I was provided with a very good summary:

FIA has contracted IFPEN Transports Energie Carnot Institute (https://www.ifpenergiesnouvelles.com/in ... -institute) to study different options for future F1 PUs. FIA's initial guidelines suggests ultra-downsizing to roughly half the current engine displacement. Fuel mass flow and on-board fuel will halve. BTE target is set to 60%. Emission regulations and P4 hybridization with front axle recovery have also been suggested but do not appear to be firm targets.

Technologies proposed to achieve these objectives include:
-Removing the CR limit
-HCCI and spark-assisted HCCI
-2 stage supercharging
-Water injection

At the moment they seem to be leaning towards keeping the MGUH.
Teams are expected to feed back which of these technologies they would like to pursue. As manufacturers start finding common ground the regulations will start to firm up.

Any thought on this? Half fuel flow, but 60% BTE would still mean 40% less power... how can they compensate?Even a bigger MGU-K would need to be powered somehow...

[Big Tea]

I've got in touch with someone who attended the ImechE conference I've mentioned in the previous posts. Did not manage to get any of the presentations but I was provided with a very good summary:

FIA has contracted IFPEN Transports Energie Carnot Institute (https://www.ifpenergiesnouvelles.com/in ... -institute) to study different options for future F1 PUs. FIA's initial guidelines suggests ultra-downsizing to roughly half the current engine displacement. Fuel mass flow and on-board fuel will halve. BTE target is set to 60%. Emission regulations and P4 hybridization with front axle recovery have also been suggested but do not appear to be firm targets.

Technologies proposed to achieve these objectives include:
-Removing the CR limit
-HCCI and spark-assisted HCCI
-2 stage supercharging
-Water injection

At the moment they seem to be leaning towards keeping the MGUH.
Teams are expected to feed back which of these technologies they would like to pursue. As manufacturers start finding common ground the regulations will start to firm up.

Any thought on this? Half fuel flow, but 60% BTE would still mean 40% less power... how can they compensate?Even a bigger MGU-K would need to be powered somehow...

Would there be a reduction in weight to off set the 60% power? There would be a lower starting weight as they would carry less fuel anyway.

I don't know how much the loss of power would affect the racing as all cars would be on par. Look back to when there was less power and the racing was at least as good as now. Longer lap tomes would be a bonus and cut down on crowding too. It is just the numbers that some seem to need to be impressed by rather than the racing.

Technologically it is more advanced to get the power from smaller engines and flow and the car would be more important than the engine.

[Blackout]

Achieving 60% BTE would cost weight too (a water tank for water injection + supercharger + MGUH etc)

[djos]

I'd be very happy to see the current V6 retained but delete the HERS system and go Twin-turbo + E85 Biofuel + 30% higher fuel flow-rate (to account for the lower energy density of Ethanol). It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance.

That would keep the engines at around 1,000HP and they would sound good due to not being muffled by an MGU-H system. Turbo engines still sound great if done right - my little 3-Banger Turbo has a great raspy note and all I've done to it is have it Tuned. I'm planning to delete the resonator at some point to make it even louder.

[Bandit1216]

I know a great way to reduce weight. Keep a max flow rate. Make the throttle by wire system make it impossible to drive off with the fuel hose in the car during re-fueling in the race. tadaaaaa

[henry]

. It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance..

Currently with 120kW they harvest about 1MJ per lap under braking. 250kW On the rear axle might harvest about 80% more, they’d run out of traction at about 160kph. Without H its hard to see where the rest of that 10MJ comes from, perhaps drive against the K at part throttle for 30 seconds? But that uses fuel, maybe at some tracks in qualy only but in the race they’d be restricted to 2 MJ like now.

[djos]

. It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance..

Currently with 120kW they harvest about 1MJ per lap under braking. 250kW On the rear axle might harvest about 80% more, they’d run out of traction at about 160kph. Without H its hard to see where the rest of that 10MJ comes from, perhaps drive against the K at part throttle for 30 seconds? But that uses fuel, maybe at some tracks in qualy only but in the race they’d be restricted to 2 MJ like now.

Thanks for the explanation, math was never one of my strong points.

[lucafo]

. It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance..

Currently with 120kW they harvest about 1MJ per lap under braking. 250kW On the rear axle might harvest about 80% more, they’d run out of traction at about 160kph. Without H its hard to see where the rest of that 10MJ comes from, perhaps drive against the K at part throttle for 30 seconds? But that uses fuel, maybe at some tracks in qualy only but in the race they’d be restricted to 2 MJ like now.

Thats why I would go to electrify the front axle. It would recovery more energy.

[Jolle]

. It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance..

Currently with 120kW they harvest about 1MJ per lap under braking. 250kW On the rear axle might harvest about 80% more, they’d run out of traction at about 160kph. Without H its hard to see where the rest of that 10MJ comes from, perhaps drive against the K at part throttle for 30 seconds? But that uses fuel, maybe at some tracks in qualy only but in the race they’d be restricted to 2 MJ like now.

Thats why I would go to electrify the front axle. It would recovery more energy.

The problem with that at the moment is brake feel. Although they made big steps on the rear BBW, it's still not as good as a hydraulic only system.
For WEC, where this is more common practice on hybrid cars, this is less of an issue, because WEC cars are less about pure wheel to wheel action and more about efficiency.

[henry]

. It would also be nice to see the MGU-K System boosted to say 250kW max power and with say a big 10 MJ/lap deployment allowance..

Currently with 120kW they harvest about 1MJ per lap under braking. 250kW On the rear axle might harvest about 80% more, they’d run out of traction at about 160kph. Without H its hard to see where the rest of that 10MJ comes from, perhaps drive against the K at part throttle for 30 seconds? But that uses fuel, maybe at some tracks in qualy only but in the race they’d be restricted to 2 MJ like now.

Thats why I would go to electrify the front axle. It would recovery more energy.

I think it would also add a number of constraints that would reduce performance. There would be additional weight for the MGU(s) and associated gearbox(s), Half shafts, electrical connectors etc. An increased chassis size around the suspension area affecting aero. And chassis load paths.

In return you would get a MJ or 2 per lap. And lots of controversy over torque vectoring.

[Blackout]

Well, even with diminutive ICEs, less on-board fuel and tiny heat rejection I don't think I can see the weight reducing

The battery will be heavier and the electric front axle will require big reduction stages for the high speed electric motors.

"If overall PU output is to be conserved"... but maybe we dont need to conserve 1000hp. What if they set the fuel flow at 75kg/hour? wont the engine produce around 750hp with that 60% BTE level and the same fuel as today? 750hp is a good base : )
But then again, how to achieve 60% TE without increasing the weight of the PU...

[Zynerji]

1.5l, 2T, Inline 5 that revs to 12k.

Ditch the hybrid, and bring the noise!

[mclaren111]

Hell Yes

[63l8qrrfy6]

Well, even with diminutive ICEs, less on-board fuel and tiny heat rejection I don't think I can see the weight reducing

The battery will be heavier and the electric front axle will require big reduction stages for the high speed electric motors.

"If overall PU output is to be conserved"... but maybe we dont need to conserve 1000hp. What if they set the fuel flow at 75kg/hour? wont the engine produce around 750hp with that 60% BTE level and the same fuel as today? 750hp is a good base : )
But then again, how to achieve 60% TE without increasing the weight of the PU...

I think a good chunk of the increased TE is meant to come from high ethanol fuels and inherent knock resistance. I wouldn't say a more efficient engine is necessarily heavier.

Only the ICE output (currently 800 hp give or take) is affected by the fuel flow limit but it is difficult to speculate what the output would be at 75 l/h and 60% TE without knowing what the fuel composition (and hence heating value) is. They have already confirmed the fuel is changing so there is little point to consider current fuels.

The other thing we don't seem to know is what the target laptimes are. It's understood that from the aero changes the cars will be some 1-3seconds slower from different sources. Would they afford to lose more lap time from the PU side on top of that ?

It's nice for users to state what they would like to see but the reality is next engines will be smaller displacement, fewer cylinder and the electric motor output will increase.