2025/2026 Hybrid Powerunit speculation

[Blackout]

Thanks. Are they concidering high methanol fuels too? (an ethanol-methanol-gasoline mix)

[Jolle]

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.

That the next step is to decrease the engine capacity sounds logical at first, but with turbo engines not that obvious. Seeing across the board that ICE development is slowing down or even stops, a smaller new engine wil require a lot of investment from the several companies. The current engine freeze might give as a bit more insight, that the next version is a dumbed down ICE, that won't be a differentiator anymore and move the focus on recovery, from a H unit or new horizons like front axle recovery (while keeping that analoge brake feeling), with a focus on software.

Now we already have set values for amount of cylinders, bore, V angle, COG and weight with a standerd fuel system oncoming. I can see a standerd combustion chamber design in the next engine formula.

[63l8qrrfy6]

"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.

That the next step is to decrease the engine capacity sounds logical at first, but with turbo engines not that obvious. Seeing across the board that ICE development is slowing down or even stops, a smaller new engine wil require a lot of investment from the several companies. The current engine freeze might give as a bit more insight, that the next version is a dumbed down ICE, that won't be a differentiator anymore and move the focus on recovery, from a H unit or new horizons like front axle recovery (while keeping that analoge brake feeling), with a focus on software.

Now we already have set values for amount of cylinders, bore, V angle, COG and weight with a standerd fuel system oncoming. I can see a standerd combustion chamber design in the next engine formula.

It is exactly why in on of my earlier posts I speculated that they will just go for the inline 3 and almost entirely reuse one of the existing engine banks. I think spec combustion chamber may be a bit extreme.

The way I see engine capacity and fuel flow rates:
-If the capacity reduces in proportion to fuel flow rate then thermal and mechanical loads stay almost the same. This is cheap for current manufacturers.
-If the capacity drops but fuel flow limits is preserved (or decreases very little) then the thermal and machanical loads increase drastically - this is expensive for current and existing manufacturers.
-if the capacity reduces very little but fuel flow decreases dramatically then thermal and mechanical loads also decrease massively meaning components have to be re-optimized which is expensive for current manufacturers and challenging for newcomers.

I think the pragmatic approach is to reduce the fuel flow rate in proportion to engine displacement.

[63l8qrrfy6]

Thanks. Are they concidering high methanol fuels too? (an ethanol-methanol-gasoline mix)

No idea what the new fuels are but I was under the impression they have given details in media.
Can't find it for the life of me.

[JordanMugen]

It is exactly why in on of my earlier posts I speculated that they will just go for the inline 3 and almost entirely reuse one of the existing engine banks. I think spec combustion chamber may be a bit extreme.

Why inline-three and not V4? Wouldn't the 1.05L V4 be better suited to the forming the rear-end structure of the vehicle?

Current:
1.6 L V6 turbo ~840bhp
ERS system ~160 bhp
---
Total ~1000bhp

2025 unit:
1.05L V4 turbo ~560bhp
ERS system ~440 bhp
---
Total ~1000bhp

That would make sense, wouldn't it? The vehicle weight could go up to 850 kg, 900 kg or more to support all the extra batteries needed to support the increased 440 electric hp, and that's no issue, that is the way of the world.

Seeing across the board that ICE development is slowing down or even stops, a smaller new engine wil require a lot of investment from the several companies.

It's just the current engine with two cylinders chopped off... How much could it possibly cost? Sure it will need a smaller turbo and a smaller intercooler, but the combustion chamber components would remain identical.

Of course a V10 or V12 would be even cheaper, but the organisers seem disinterested.

[Stu]

If Ferrari were doing what I think they were doing, the FIA have already stymied the best possible development which is to operate the ICE as more proportionally a generator for the Electrical drive systems, if that had been a part of the plan the 10MJ of electrical energy use per lap would be ‘on’ if they went to front axle KERS as well for 2025/6 development.
Electric drive only in the pit lane would be a good step, too.
I would also like to see inline-4 specified in the regulations, too.

[NL_Fer]

A V4 looks like even less rework compared to an i3. Especially if you keep the MGU-H in an split turbine/compressor configuration.

Also a V4 is only 33% smaller instead, less drastic than 50% reduction.

Still Redbull would keep pressing for a low cost solution, otherwise they are screwed without an engine partner.

[63l8qrrfy6]

It is exactly why in on of my earlier posts I speculated that they will just go for the inline 3 and almost entirely reuse one of the existing engine banks. I think spec combustion chamber may be a bit extreme.

Why inline-three and not V4? Wouldn't the 1.05L V4 be better suited to the forming the rear-end structure of the vehicle?

With an inline 3 you can just re-use the cylinder head casting and camshafts. The gas exchange dynmics in the intake and exhaust manifolds are also unchanged so the same specifications can be re-used (even though packaging requirements will be different). It is cheaper overall, of that I have no doubt.

I think all teams except Ferrari were happy with the 1.6 inline 4 engine architecture over the V6 at the start of the hybrid era so I can't see there beeing too many objections over an inline 3.

[Zynerji]

It is exactly why in on of my earlier posts I speculated that they will just go for the inline 3 and almost entirely reuse one of the existing engine banks. I think spec combustion chamber may be a bit extreme.

Why inline-three and not V4? Wouldn't the 1.05L V4 be better suited to the forming the rear-end structure of the vehicle?

With an inline 3 you can just re-use the cylinder head casting and camshafts. The gas exchange dynmics in the intake and exhaust manifolds are also unchanged so the same specifications can be re-used (even though packaging requirements will be different). It is cheaper overall, of that I have no doubt.

I think all teams except Ferrari were happy with the 1.6 inline 4 engine architecture over the V6 at the start of the hybrid era so I can't see there beeing too many objections over an inline 3.

Newey pushed back against the I4 for the V6 layout for "packaging" reasons.

[63l8qrrfy6]

Why inline-three and not V4? Wouldn't the 1.05L V4 be better suited to the forming the rear-end structure of the vehicle?

With an inline 3 you can just re-use the cylinder head casting and camshafts. The gas exchange dynmics in the intake and exhaust manifolds are also unchanged so the same specifications can be re-used (even though packaging requirements will be different). It is cheaper overall, of that I have no doubt.

I think all teams except Ferrari were happy with the 1.6 inline 4 engine architecture over the V6 at the start of the hybrid era so I can't see there beeing too many objections over an inline 3.

Newey pushed back against the I4 for the V6 layout for "packaging" reasons.

Regardless they all agreed on an inline engine until Audi decided not to build an engine.

[Jolle]

It is exactly why in on of my earlier posts I speculated that they will just go for the inline 3 and almost entirely reuse one of the existing engine banks. I think spec combustion chamber may be a bit extreme.

Why inline-three and not V4? Wouldn't the 1.05L V4 be better suited to the forming the rear-end structure of the vehicle?

Current:
1.6 L V6 turbo ~840bhp
ERS system ~160 bhp
---
Total ~1000bhp

2025 unit:
1.05L V4 turbo ~560bhp
ERS system ~440 bhp
---
Total ~1000bhp

That would make sense, wouldn't it? The vehicle weight could go up to 850 kg, 900 kg or more to support all the extra batteries needed to support the increased 440 electric hp, and that's no issue, that is the way of the world.

Seeing across the board that ICE development is slowing down or even stops, a smaller new engine wil require a lot of investment from the several companies.

It's just the current engine with two cylinders chopped off... How much could it possibly cost? Sure it will need a smaller turbo and a smaller intercooler, but the combustion chamber components would remain identical.

Of course a V10 or V12 would be even cheaper, but the organisers seem disinterested.

If they just chop off two cylinders or even go all seventies and go back to a V12, it would mean a big mountain to climb for any new entry. To make the base a quite simple V6 1.6 with regulated dimensions internally and a standard combustion chamber, VW, BMW or Toyota could enter and be competitive from the start without years of teething problems. Aston Martin even could be a real works team and order a ICE at Cosworth. And the same goes for McLaren. It opens up the field a lot more then sticking with the current highly sophisticated ICE design where multiple big companies couldn’t get their heads round.

[Zynerji]

What about an OpenFormula idea?

1. F1 pays Cosworth to build a "simple" 1.6l v6 with DOHC/VVT/twin turbo with a high power, Honda-like IMA electric motor (MagnettiMarelli maybe).

2. Then the teams all start with that design, and can upgrade it at will (maybe spec the crank/journals/rods), but all upgrade designs and test data would need to be fed back into the system so it could be accessed by all.

3. Then the FIA only polices the match of real parts to published designs. It becomes more of a high end Quality Control method instead of the cloak and dagger interpretation fest, doomed by politics that we currently have.

4. F1 Sells early access to the published data to media outlets for "inside story info". This stream of income then gets split evenly amongst the teams.

Anyways, the engine parity would quickly converge, the sharing of data will chop costs to manufacturers (no more learning in isolation), and allow high-speed tech transfer to road cars as there is no secret tech to keep hidden.

Then they can go aero/suspension nuts with the savings.

[JordanMugen]

Anyways, the engine parity would quickly converge, the sharing of data will chop costs to manufacturers (no more learning in isolation), and allow high-speed tech transfer to road cars as there is no secret tech to keep hidden.

This sounds similar to the homologation process used for Ford and Chevrolet small block V8s in V8 Supercars.

[Stu]

There used to be a rule in Superstox (UK oval formula) where a competitor could buy your engine for set price, if offered it was not permitted to refuse (and if you tried it would be stripped by the scrutineering team anyway). That tended to work as a parity formula!!
On the other hand Hot Rods (another UK oval formula) did not have that and people were spending 10x the set price on single engines.
Both had the same organising/promoting body.

[godlameroso]

I agree with pooled development. What about teams getting funding and help via fans through cloud computing?