2025/2026 Hybrid Powerunit speculation

[wuzak]

Was thinking there must be a clause like that.

I guess the long spooling time means they can’t use the K to speed up the engine while it’s declutched on the grid.

This gives us our 5 sec (or more) spool time. But how good would it have been to see all 20 cars (22 if counting Cadillac) mega blip the ICE with the now-500hp MGUK, late fuel, late spark, and throw a flame for a couple seconds right before the launch...

Is there a correlating specification for what ICE speed (& thus fuel qty) and/or MGUK regen power can be used during declutch/idle/standstill. A sidenote is that this would go some way to telling us how much heat these passive cooling systems can soak up at a standstill.

I would imagine the part throttle fuel flow rules would determine the amount that could be recovered.

Also, the net power of the PU would be what the clutch can hold for preloading at the start.

The launch would, therefore, not be the increse in power from the ICE, at least not completely, but the reduction of recovery.

[michl420]

As I understand this, this is a possible race start procedure?!:
1 red light: ice up to rpm (10500?)
2 red light: MGUK start regeneration with allowed power (200kw?, 350kw?), batterie must be not full
lights out: MGUK reduces regeneration like driver demand.
This would give full power very early, and a (mostly) electric controlled start (if it is desired).

This preload had also nothing to do with the driveshaft cluch, because ICE and MGUK are both located "before" it.

[gruntguru]

@Wuzak - under the rules is it possible they can run the engine in generator mode with the car stationary? What fuel flow would be available? They could certainly do this with radically retarded timing to generate hot exhaust gas.

It seems so. . . .
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. . . .
It looks to be specifically allowed!

As to the fuel flow allowed during this pre-launch spool-up phase, do you think it will be just the 869 MJ/hr from 5.4.5 below?
5.4.5 At partial load, the fuel energy flow must not exceed the limit curve defined below:
• EF (MJ/h) = 380 when the engine power is equal to or below -50kW
• EF (MJ/h) = 9.78 x engine power (kW) + 869 when the engine power is above -50kW
That might be enough if combined with late spark timing.