2025/2026 Hybrid Powerunit speculation

[mzso]

yes there's something in the rules ....
monotonicity .....
for any rpm above idle PU torque output must always increase with increase in accelerator displacement
(so the PU behaves like a conventional engine not a freak show)

Still, ICE actuating versus MGUK recovery, can amount to zero torque output of whole PU.

But if the same wording applies to PU and ICE that would be an effective clampdown on what I'm guessing.

I think the whole monotonicity thing means you can't do that.

If it's worded like this it doesn't at all. As long as the peak output isn't reached the ICE can go above what's requested and the MGU can generate.

[BassVirolla]

Still, ICE actuating versus MGUK recovery, can amount to zero torque output of whole PU.

But if the same wording applies to PU and ICE that would be an effective clampdown on what I'm guessing.

I think the whole monotonicity thing means you can't do that.

If it's worded like this it doesn't at all. As long as the peak output isn't reached the ICE can go above what's requested and the MGU can generate.

The only point in regs that approaches this (and does not clamp down on it) is in chapter 5.14 of the 2026 engine regulations.

I still think that we will possibly see engines generating electricity while not transmitting the power to the wheels.

Edit: Now I get your point. Yes, I think you're right. It's not the same power or torque output from the ICE that the output of the whole PU.

[wuzak]

yes there's something in the rules ....
monotonicity .....
for any rpm above idle PU torque output must always increase with increase in accelerator displacement
(so the PU behaves like a conventional engine not a freak show)

Still, ICE actuating versus MGUK recovery, can amount to zero torque output of whole PU.

But if the same wording applies to PU and ICE that would be an effective clampdown on what I'm guessing.

I think the whole monotonicity thing means you can't do that.

C5.14.3 At any given engine speed the driver torque demand map must be monotonically increasing for an increase in accelerator pedal position.

Basically, as I read it, so long as the driver's pedal position doesn't change, the ICE can increase power output and the MGUK can increase recovery so that the nett result is the same torque/power output from the PU.

That is, if the driver demands 200kW with the pedal, the ICE can go to full power (if rpm is in the right range) of 400kW and the MGUK can recover 200kW for a nett output of 200kW.

However, the partial load fuel flow rules limits the ICE output with the fuel flow.

[BassVirolla]

Still, ICE actuating versus MGUK recovery, can amount to zero torque output of whole PU.

But if the same wording applies to PU and ICE that would be an effective clampdown on what I'm guessing.

I think the whole monotonicity thing means you can't do that.

C5.14.3 At any given engine speed the driver torque demand map must be monotonically increasing for an increase in accelerator pedal position.

Basically, as I read it, so long as the driver's pedal position doesn't change, the ICE can increase power output and the MGUK can increase recovery so that the nett result is the same torque/power output from the PU.

That is, if the driver demands 200kW with the pedal, the ICE can go to full power (if rpm is in the right range) of 400kW and the MGUK can recover 200kW for a nett output of 200kW.

However, the partial load fuel flow rules limits the ICE output with the fuel flow.

100kW worth of fuel flow when not pressing the throttle pedal.

Nevertheless, the tracks with less recovery will also be the most fuel demanding. I doubt anybody will burn fuel only for recovery. Looks more feasible to have the competition on Saturday, and a fuel saving procession in Sunday.

[wuzak]

I think the whole monotonicity thing means you can't do that.

C5.14.3 At any given engine speed the driver torque demand map must be monotonically increasing for an increase in accelerator pedal position.

Basically, as I read it, so long as the driver's pedal position doesn't change, the ICE can increase power output and the MGUK can increase recovery so that the nett result is the same torque/power output from the PU.

That is, if the driver demands 200kW with the pedal, the ICE can go to full power (if rpm is in the right range) of 400kW and the MGUK can recover 200kW for a nett output of 200kW.

However, the partial load fuel flow rules limits the ICE output with the fuel flow.

100kW worth of fuel flow when not pressing the throttle pedal.

Nevertheless, the tracks with less recovery will also be the most fuel demanding. I doubt anybody will burn fuel only for recovery. Looks more feasible to have the competition on Saturday, and a fuel saving procession in Sunday.

They will very much burn fuel for recovery.

[diffuser]

C5.14.3 At any given engine speed the driver torque demand map must be monotonically increasing for an increase in accelerator pedal position.

Basically, as I read it, so long as the driver's pedal position doesn't change, the ICE can increase power output and the MGUK can increase recovery so that the nett result is the same torque/power output from the PU.

That is, if the driver demands 200kW with the pedal, the ICE can go to full power (if rpm is in the right range) of 400kW and the MGUK can recover 200kW for a nett output of 200kW.

However, the partial load fuel flow rules limits the ICE output with the fuel flow.

100kW worth of fuel flow when not pressing the throttle pedal.

Nevertheless, the tracks with less recovery will also be the most fuel demanding. I doubt anybody will burn fuel only for recovery. Looks more feasible to have the competition on Saturday, and a fuel saving procession in Sunday.

They will very much burn fuel for recovery.

The 2026 cars may have less Down force. Which means fewer full throttle opportunities, therefore, more recovery opportunities. Even looking at the 2024 cars, you can see at a track like Silverstone, they would have been recovering in turn 9, 11-13 in between 16 and 17.

Meaning I agree with Wuzak

[Zynerji]

Is anyone actually happy with the expected 2026 engines?

I'm of the mind currently that it could seriously just be best to move to a 1.6l v6 N/A-DI 2 stroke (v12 sound, and high RPM feel) with the current (mostly) block architecture and delete the turbo. Keeping a 240kw KERS to torque fill would seem preferable for economy and drivability. Then 2008 sized cars, and I'm in.

What I see and hear for 2026 currently simply does not feel very impressive, and that is hugely disappoint to this long-time fan.

[diffuser]

Is anyone actually happy with the expected 2026 engines?

I'm of the mind currently that it could seriously just be best to move to a 1.6l v6 N/A-DI 2 stroke (v12 sound, and high RPM feel) with the current (mostly) block architecture and delete the turbo. Keeping a 240kw KERS to torque fill would seem preferable for economy and drivability. Then 2008 sized cars, and I'm in.

What I see and hear for 2026 currently simply does not feel very impressive, and that is hugely disappoint to this long-time fan.

We're not disappoint or happy about them, we're just trying to understand them. Hard to judge when you don't know exactly how it's gonna play out. At least, that's my opinion.

[BassVirolla]

100kW worth of fuel flow when not pressing the throttle pedal.

Nevertheless, the tracks with less recovery will also be the most fuel demanding. I doubt anybody will burn fuel only for recovery. Looks more feasible to have the competition on Saturday, and a fuel saving procession in Sunday.

They will very much burn fuel for recovery.

The 2026 cars may have less Down force. Which means fewer full throttle opportunities, therefore, more recovery opportunities. Even looking at the 2024 cars, you can see at a track like Silverstone, they would have been recovering in turn 9, 11-13 in between 16 and 17.

Meaning I agree with Wuzak

Not disagreeing, only wondering...

Less downforce puts more emphasis (lap time) in weight (fuel) savings.

As you reply to Zynerji, it's difficult to judge what we don't even know how will pan out.

[Chuckjr]

Is anyone actually happy with the expected 2026 engines?

I'm of the mind currently that it could seriously just be best to move to a 1.6l v6 N/A-DI 2 stroke (v12 sound, and high RPM feel) with the current (mostly) block architecture and delete the turbo. Keeping a 240kw KERS to torque fill would seem preferable for economy and drivability. Then 2008 sized cars, and I'm in.

What I see and hear for 2026 currently simply does not feel very impressive, and that is hugely disappoint to this long-time fan.

Agree 100%. I hate where 2026 is going also and I’ve been a fan since 1986.

[wuzak]

Is anyone actually happy with the expected 2026 engines?

I'm of the mind currently that it could seriously just be best to move to a 1.6l v6 N/A-DI 2 stroke (v12 sound, and high RPM feel) with the current (mostly) block architecture and delete the turbo. Keeping a 240kw KERS to torque fill would seem preferable for economy and drivability. Then 2008 sized cars, and I'm in.

What I see and hear for 2026 currently simply does not feel very impressive, and that is hugely disappoint to this long-time fan.

The ICE doesn't need to be 1.6L to make the ~400kW projected for 2026, since they make ~600kW now with, more or less, the same airflow.

They coould have made the ICE 1.1L - 1.2L, and make it smaller and lighter.

A 2 stroke could be made using the same architecture, but would need the turbo, and possibly an MGUH, for it to work.

It would either need more fuel flow, or smaller capacity.

It should sound better.

350kW KERS isn't too bad, just reduce the battery size, so that it can only be used in short bursts out of corners.

With less power transfer between the battery and the MGUK (in and out) they could probably save weight with smaller ERS coolers.

[Martin Keene]

Is anyone actually happy with the expected 2026 engines?

I'm of the mind currently that it could seriously just be best to move to a 1.6l v6 N/A-DI 2 stroke (v12 sound, and high RPM feel) with the current (mostly) block architecture and delete the turbo. Keeping a 240kw KERS to torque fill would seem preferable for economy and drivability. Then 2008 sized cars, and I'm in.

What I see and hear for 2026 currently simply does not feel very impressive, and that is hugely disappoint to this long-time fan.

You'd need a supercharger or a completely different block architecture for a two stroke. A four stroke has a completely independent inlet stroke to draw in the inlet charge. A two stroke requires the use of the crankcase to force the charge from the bottom of the engine to the top for nat asp engines, or a mechanically driven supercharge to force the charge in against the exhaust plume.

[Tommy Cookers]

You'd need a supercharger or a completely different block architecture for a two stroke. A four stroke has a completely independent inlet stroke to draw in the inlet charge. A two stroke requires the use of the crankcase to force the charge from the bottom of the engine to the top for nat asp engines, or a mechanically driven supercharge to force the charge in against the exhaust plume.

'uniflow' (ie non crankcase-induction) 2 strokes have since the 1920s not (once started) needed a blower
(eg Petter 'Harmonic' and Crossley in the UK)
by having tuned-length exhaust systems .. and specially eg if they have eg an 8 speed transmission ....
yes a bit of induction air pressure (eg electrically-driven) is needed for starting
the hybrid F1 rules manage fueling and manage ICE load in a way helpful to the this ICE type

but the Zynergi-architecture engine won't have the sound he wants because the firing intervals will be so uneven

[FW17]

You'd need a supercharger or a completely different block architecture for a two stroke. A four stroke has a completely independent inlet stroke to draw in the inlet charge. A two stroke requires the use of the crankcase to force the charge from the bottom of the engine to the top for nat asp engines, or a mechanically driven supercharge to force the charge in against the exhaust plume.

'uniflow' (ie non crankcase-induction) 2 strokes have since the 1920s not (once started) needed a blower
(eg Petter 'Harmonic' and Crossley in the UK)
by having tuned-length exhaust systems .. and specially eg if they have eg an 8 speed transmission ....
yes a bit of induction air pressure (eg electrically-driven) is needed for starting
the hybrid F1 rules manage fueling and manage ICE load in a way helpful to the this ICE type

but the Zynergi-architecture engine won't have the sound he wants because the firing intervals will be so uneven

If it is a 2 stroke, it should be as a range extender only, non structural. The electrical generator unit and motor units can become the structure of the car.

Probably an automatic 4 speed gear box to spin the generator to very high rpm to make the motor unit very light and small.

[Zynerji]

You'd need a supercharger or a completely different block architecture for a two stroke. A four stroke has a completely independent inlet stroke to draw in the inlet charge. A two stroke requires the use of the crankcase to force the charge from the bottom of the engine to the top for nat asp engines, or a mechanically driven supercharge to force the charge in against the exhaust plume.

'uniflow' (ie non crankcase-induction) 2 strokes have since the 1920s not (once started) needed a blower
(eg Petter 'Harmonic' and Crossley in the UK)
by having tuned-length exhaust systems .. and specially eg if they have eg an 8 speed transmission ....
yes a bit of induction air pressure (eg electrically-driven) is needed for starting
the hybrid F1 rules manage fueling and manage ICE load in a way helpful to the this ICE type

but the Zynergi-architecture engine won't have the sound he wants because the firing intervals will be so uneven

So, non-flat crank and no big-bang?

Not a 2stroke guy, but chain-sawing firewood recently seemed so simple and elegant with seemingly solvable drawbacks.

But just the current (modified) block with 2 stroke heads, probably hot V seemed like it could just be a simpler way to go. I haven't even gotten to the point of asking about using nitro-methane in them... Would 100L get a car to the end??