2026 Hybrid Powerunits

[Vappy]

At 17s, is that charging at a standing start?

I'm not sure if i've heard that exhaust-modulating sound for a launch. Up until last year, I have heard it mostly during off-throttle / braking. Mercedes had a pretty clean MGU-H energy recovery method up until the recent engine change, which while not as exciting as Honda's (personal opinion), it was still audibly prominent and consistent at races.

EDIT: I am mistaken. They did make that sound previously for launches.

[lio007]

By the way when will the PUs be homologated? Could one of the other manufacturers have rushed to create an expanding conrod, or piston or whatever since this first came out?

https://autoracer.it...rezza-alla-fia/

This is not a usable url.

Homologation deadline is March 1st.

[saviour stivala]

... It can only charge if the rear axle is rotating.

fwiw I disagree ....
though of course the MGU-K torque is capped below c.6200 rpm equivalent

Not only can the MGU-K charge ES only when the rear axle is 'rotating', but also when the car is moving at past 50 km/h, and to me it looks like when the car is moving at 50 km/h the MGU-K will be more like deploying than harvesting.

[mzso]

At 17s, is that charging at a standing start?

How would it charge? It can only charge if the rear axle is rotating.

There's no mechanical reason for that. No one quoted any regs in this regard so far either.

[mzso]

Homologation deadline is March 1st.

So it's not too late to start on it?

[wuzak]

At 17s, is that charging at a standing start?

How would it charge? It can only charge if the rear axle is rotating.

Clutch slipping.

[mzso]

At 17s, is that charging at a standing start?

How would it charge? It can only charge if the rear axle is rotating.

Clutch slipping.

Why would the clutch come into play? It should be disengaged.

[BassVirolla]

At 17s, is that charging at a standing start?

How would it charge? It can only charge if the rear axle is rotating.

Clutch slipping.

To me, it sounds like some revs before start harvesting, and then a quite heavy load applied (harvesting).

Clutch slipping just because it's not in neutral. If it was in neutral, this is not more (nor less) than a 350kw generator.

[PlatinumZealot]

There is a Dongfeng 1.5L engine built for commercial use that is at 48%

https://encrypted-tbn0.gstatic.com/imag ... YZDSsMPA&s

You can do this using many techniques...

I guess that is why we see all cars nowadays with 45% efficiency on the road

It's easier to make a slow rating engine efficient than a fast rotating one. One headline efficiency figure doesn't mean much.

You can't compare a formula 1 engine to a street car engine. Too many variables at play. Different combustion, different friction, different temperstures etc.

[saviour stivala]

''CLUTCH SLIPPING'' ---This was thrown-in as a possibility that will allow the ES to be charged, as suggested, actually asked, if that sound was as a possibility of the ES was being charged with the car at 'STANDING START'. And all this is taking place/being said on a technical forum, Could be some knickers have suddenly dropped and tripped some people.

[wuzak]

How would it charge? It can only charge if the rear axle is rotating.

Clutch slipping.

Why would the clutch come into play? It should be disengaged.

If it is fully disengaged, the start will be slow due to the time needed to engage the clutch.

It's why the teams take every opportunity to do practice starts on a weekend - to determine the throttle position, rpm (ie power) and the clutch bite point for the best possible launch at the start of the race.

If the power that can be used at launch is 100kW, the ICE could make its maximum power and the MGUK would recover the difference.

[AR3-GP]

At 17s, is that charging at a standing start?

How would it charge? It can only charge if the rear axle is rotating.

Is this due to regulations or a physical mechanism?

[wuzak]

C5.2.12 During a standing start from the grid the MGU-K may only be used once the car has reached 50 km/h.

[Used = deploying?]

C5.2.19 When the car is stationary on the grid prior to a standing start the MGU-K torque may only be negative (i.e. charging the ES) except for torque requested by an MGU-K active damping strategy whose sole purpose is to protect the MGU-K Mechanical Transmission.

[saviour stivala]

C5.2.12 During a standing start from the grid the MGU-K may only be used once the car has reached 50 km/h.

[Used = deploying?]

C5.2.19 When the car is stationary on the grid prior to a standing start the MGU-K torque may only be negative (i.e. charging the ES) except for torque requested by an MGU-K active damping strategy whose sole purpose is to protect the MGU-K Mechanical Transmission.

At a standing start the MGU-K can only be used after the first 50 meters or when the car attains 50 km/h. The warding ''cannot be used/can only be used will surly cover both deployment as well as harvesting.

[saviour stivala]

Clutch slipping.

Why would the clutch come into play? It should be disengaged.

Not before the car has reached 50 km/h. Only than can the MGU-K be 'USED'.
If it is fully disengaged, the start will be slow due to the time needed to engage the clutch.

It's why the teams take every opportunity to do practice starts on a weekend - to determine the throttle position, rpm (ie power) and the clutch bite point for the best possible launch at the start of the race.

If the power that can be used at launch is 100kW, the ICE could make its maximum power and the MGUK would recover the difference.

Only when the car has reached 50 km/h can the MGU-K be ''USED''.