2025/2026 Hybrid Powerunit speculation

[FittingMechanics]

How difficult would it be to change the 50/50 split to a 60/40 immediately and then a 70/30 split after the summer brake ?

If you just reduce the MGU-K power then it is not hard at all. They can do this by introducing a software limit (I think FIA is allowed to do that already)

But, reduction in power would only mean they use the MGU-K for longer. Most of the complaints would still apply, they would still harvest in a similar way, they would still be able to yoyo, they would be even slower, etc.

Even if you increase ICE power, all of these still apply.

[wuzak]

How difficult would it be to change the 50/50 split to a 60/40 immediately and then a 70/30 split after the summer brake ?

If you just reduce the MGU-K power then it is not hard at all. They can do this by introducing a software limit (I think FIA is allowed to do that already)

But, reduction in power would only mean they use the MGU-K for longer. Most of the complaints would still apply, they would still harvest in a similar way, they would still be able to yoyo, they would be even slower, etc.

Even if you increase ICE power, all of these still apply.

If ICE power is increased using inccreased fuel flow across the rpm range, then there will be more opprotunity for part throttle recovery - more time where ICE power exceeds the driver's demands and potentially more difference between ICE power and demand.

[FittingMechanics]

How difficult would it be to change the 50/50 split to a 60/40 immediately and then a 70/30 split after the summer brake ?

If you just reduce the MGU-K power then it is not hard at all. They can do this by introducing a software limit (I think FIA is allowed to do that already)

But, reduction in power would only mean they use the MGU-K for longer. Most of the complaints would still apply, they would still harvest in a similar way, they would still be able to yoyo, they would be even slower, etc.

Even if you increase ICE power, all of these still apply.

If ICE power is increased using inccreased fuel flow across the rpm range, then there will be more opprotunity for part throttle recovery - more time where ICE power exceeds the driver's demands and potentially more difference between ICE power and demand.

I'm no expert but I think increasing fuel limit has massive ramifications for the design of the ICE. I don't think this is a realistic change mid season. Could be wrong though *shrugs*.

[bananapeel23]

How are teams modeling harvesting/deployment strategies on high energy tracks? It must be really difficult to figure out how to best deploy and harvest in Shanghai. Harvest too aggressively and you will have harvested the full 9MJ going into, or part way through the hairpin. That would cost you both braking power and acceleration out of the hairpin, at best costing you a lot of time, at worst causing lockups or cars going very wide.

Obviously you will want to harvest every little bit of the 9MJ available, but you also don't want to harvest or deploy in inefficient locations, but the 4 MJ battery must make modelling deployment and harvesting extremely difficult, while effective distribution of energy could be worth seconds per lap, even if both cars get the full 9 MJ.

Are teams brute forcing it in the simulator? Are they manually calculating where to use the energy? Are they training neural nets on simplified versions of the track to find candidates, then testing it in the sim? Does anyone know?

[Dr. Acula]

I'm no expert but I think increasing fuel limit has massive ramifications for the design of the ICE. I don't think this is a realistic change mid season. Could be wrong though *shrugs*.

Well, a higher energy flow also means you need more fuel to begin with. The question here is, if the fuel tanks they have fitted in the car now, can even hold significantly more fuel for the race. I don't think so, because why would you design the tank bigger than it absolutly has to be? And as the fuel tank is fitted to the chassis, basically that could mean that a new chassis would be required.

[Martin Keene]

How difficult would it be to change the 50/50 split to a 60/40 immediately and then a 70/30 split after the summer brake ?

If you just reduce the MGU-K power then it is not hard at all. They can do this by introducing a software limit (I think FIA is allowed to do that already)

But, reduction in power would only mean they use the MGU-K for longer. Most of the complaints would still apply, they would still harvest in a similar way, they would still be able to yoyo, they would be even slower, etc.

Even if you increase ICE power, all of these still apply.

If ICE power is increased using inccreased fuel flow across the rpm range, then there will be more opprotunity for part throttle recovery - more time where ICE power exceeds the driver's demands and potentially more difference between ICE power and demand.

Whilst in theory increasing fuel flow is easy, in reality, it is a lot harder. Teams will have based the fuel tank size around the fuel flow limit vs the longest race/fuel consumption, so they likely do not have a fuel tank big enough to support an increase in fuel flow. That is probably the easiest obstacle to overcome, more of a challenge is the duty cycle of the engine will have been defined around that fuel flow limit and then the engine designed to that duty cycle.

Increasing fuel flow will increase the duty cycle so will shorten engine life and will require some redesign of the engine. How much of a redesign, is anyone's guess.