2025/2026 Hybrid Powerunit speculation

[AR3-GP]

Detune the MGU-K enough and it simply isn't worth it to give up the speed for the acceleration boost out of the following corner, even if you don't reach the harvesting allowance.

Are we sure about that? I'm trying to understand if anything really changes. You always want to dump energy into the first part of the straight, so that you carry it all the way along. If you detune the MGU-K, it just means they'll need less of the superclipping, but they'll always do just enough I think?

[FW17]

750 hp constant is enough for bring back good racing.

If the FIA feels there is too much grip, they should limit the size of rear wing further.

[padajacaba]

Furthermore, the total power reduction is limited to a maximum of 600kW and the resulting electrical DC power of the ERS-K must remain above −250kW.

I would change the underlined sections to 350kW (or whatever deployment is reduced to) "must not be negative".

This would, likely, need to be accompanied by an increase in fuel flow to increase ICE power.

I'd let them reduce by around 400kW, but that's pretty much my take too. 50kW clipping would still allow a decent amount of recharge in on straights (not all that different from what the amount the derated to in the MGU-H era) and leave about 500hp at the wheels, which would be enough to keep these cars over 300kph with the wings open. It would mean less total recharge over a lap, so maybe combine with slightly reduced allowance and we'd probably see very different deploy strategies - going to a longer, more consistent burn rather than max power out of certain corners.

Real curious to see how it goes at China next week. Melbourne, by my estimates, is one of the worst tracks for this new power unit and Shanghai is one of the best. I don't think we'll see much super-clipping at all given that they should be able to get near the recharge limit without it on the longer lap with more braking zones and more part-throttle mini-sectors.

[mzso]

The driver has no input into that decision to slow the car down in the fast corners. We're going to see cars slow similarly in Eau Rouge and Copse and it will be awful. The rules need to be adjusted to effectively end super clipping on any track.

The adjustment we need is a reduction in peak output large enough to remove the incentive to clip through fast corners or at the end of straights.

Or clip always above a certain speed at lower rates and no one will be the wiser.

[karana]

It seems many have the belief that there is a benefit to drive slower through a fast corner in order to harvest more if there comes a long straight after. I really don't think that is the case. You would lose lots of time through the corner itself for very small amounts of energy and be also slower at the beginning of the straight. The extra energy will likely not even be enough to make up for the lack of speed and definitely not to make up for the time lost in the corner and the time lost up to the point where you caught up to the speed you would have by just driving as fast as possible.

In a way that is as if you claim it is better to super-clip in the middle of a long straight to have more energy to deploy for the rest of the straight.

There likely will be fast corners that will be taken slower than theoretically possible when the corner is close enough to an actual braking zone (like 130R in Suzuka). The super-clipping then might already start before the fast corner, but in that case it is pure 'coincidence' in the sense that it would happen even if the fast corner would be a straight. The fact that drivers drove slower through T12 in Bahrain had nothing to do with it being a corner.

[bananapeel23]

It seems many have the belief that there is a benefit to drive slower through a fast corner in order to harvest more if there comes a long straight after. I really don't think that is the case. You would lose lots of time through the corner itself for very small amounts of energy and be also slower at the beginning of the straight. The extra energy will likely not even be enough to make up for the lack of speed and definitely not to make up for the time lost in the corner and the time lost up to the point where you caught up to the speed you would have by just driving as fast as possible.

In a way that is as if you claim it is better to super-clip in the middle of a long straight to have more energy to deploy for the rest of the straight.

There likely will be fast corners that will be taken slower than theoretically possible when the corner is close enough to an actual braking zone (like 130R in Suzuka). The super-clipping then might already start before the fast corner, but in that case it is pure 'coincidence' in the sense that it would happen even if the fast corner would be a straight. The fact that drivers drove slower through T12 in Bahrain had nothing to do with it being a corner.

Driving 30 km/h slower for one second in a 250 km/h corner in order to run 30 km/h faster for one second in a 125 km/h corner saves a ton of time.

[gearboxtrouble]

It seems many have the belief that there is a benefit to drive slower through a fast corner in order to harvest more if there comes a long straight after. I really don't think that is the case. You would lose lots of time through the corner itself for very small amounts of energy and be also slower at the beginning of the straight. The extra energy will likely not even be enough to make up for the lack of speed and definitely not to make up for the time lost in the corner and the time lost up to the point where you caught up to the speed you would have by just driving as fast as possible.

In a way that is as if you claim it is better to super-clip in the middle of a long straight to have more energy to deploy for the rest of the straight.

There likely will be fast corners that will be taken slower than theoretically possible when the corner is close enough to an actual braking zone (like 130R in Suzuka). The super-clipping then might already start before the fast corner, but in that case it is pure 'coincidence' in the sense that it would happen even if the fast corner would be a straight. The fact that drivers drove slower through T12 in Bahrain had nothing to do with it being a corner.

As far as I understand it, super clipping can only happen when the engine is at 100% throttle. That means it can only be done in fast corners usually taken flat out, acceleration zones and active aero zones. Of the three you absolutely want to maximize acceleration zones because that feeds back and makes the following active aero zone faster so that you vmax quicker and can super clip extra in low drag mode as well as harvest more in the braking zone. That leaves you having to harvest in fast corners at full throttle by default - its just the optimal way to minimize laptime. Add to that the fact that its nearly impossible to pass in those corners and its even better to do so in the race. Adopting this strategy would also let you take even more downforce off the car because its unnecessary to hit these lower max cornering speeds and that reduces drag the rest of the time.

[FittingMechanics]

Detune the MGU-K enough and it simply isn't worth it to give up the speed for the acceleration boost out of the following corner, even if you don't reach the harvesting allowance.

Are we sure about that? I'm trying to understand if anything really changes. You always want to dump energy into the first part of the straight, so that you carry it all the way along. If you detune the MGU-K, it just means they'll need less of the superclipping, but they'll always do just enough I think?

It will always be faster to extract energy at the end of straight where you will soon dump it into brakes and deploy it at lower speed after the next corner.

Ek = ⁠1/2 * m * v^2

Formula is quite simple. Any Joule you extract at high speeds is worth more on following straight (and laptime benefit multiplies as you carry the speed for the whole straight). If you had to brake afterwards it is even more valuable as you'll get more kph by deploying at lower speed.

I don't think they are ever dipping below the apex speeds so the idea that it would not be worth to harvest because the power would be lower is wrong. They will fine tune their harvest to reach apex speeds in fast corners (like Russel not braking in T9 in AUS) and benefit from energy afterwards.

[gruntguru]

True. Also - near the end of straights - a lot of energy is being used to produce a very small increase in top speed. (and a very small reduction in lap-time.)

[AR3-GP]

As far as I understand it, super clipping can only happen when the engine is at 100% throttle. That means it can only be done in fast corners usually taken flat out, acceleration zones and active aero zones. Of the three you absolutely want to maximize acceleration zones because that feeds back and makes the following active aero zone faster so that you vmax quicker and can super clip extra in low drag mode as well as harvest more in the braking zone. That leaves you having to harvest in fast corners at full throttle by default - its just the optimal way to minimize laptime. Add to that the fact that its nearly impossible to pass in those corners and its even better to do so in the race. Adopting this strategy would also let you take even more downforce off the car because its unnecessary to hit these lower max cornering speeds and that reduces drag the rest of the time.

I'm not convinced about this last part because lack of downforce is what makes the midfield cars, midfield cars. People shouldn't get the impression that anybody wants to superclip. It's overrated. You're burning fuel and reducing speed to make electricity in a region where you wouldn't be slowing if the battery wasn't going to be empty somewhere after the corner.

The most efficient way to harvest is from braking. The driver would normally slow down ahead of a corner, so you might as well extract it back out with the MGU-K rather than dissipating as heat in the disc brakes. Superclipping is only 2nd best (I know that you know this, but just wanting others not to get carried away with the idea that teams would want to superclip if they had alternatives). This is also why downforce is desirable. Having downforce allows more aggressive harvesting from the rear axle in the brake zones and brake harvesting is the most efficient harvesting method.

[AR3-GP]

It was interesting seeing the overlay on the halo which showed deploy (scale from 0 to 350kw), harvest (scale from 0 to 350kw). You can see a lot of partial throttle harvesting in corner exits, as well as superclipping at 250kW before some of the corners.

[AR3-GP]

On lap 33, they showed the real-time battery level for both Verstappen and Norris for the entire lap.



I decided to track the battery level before and after each corner to figure out how much recharging was being done. This includes any superclipping done before the corner, the brake harvesting, and any part-throttle recharge on the corner exit. This is a summary of the recharge amount (do not confuse with battery level).



Then I converted the percentage to energy in units of megajoules (4MJ battery)



In practice, they didn't harvest the full 8MJ in this lap. I wonder why not. We tend to think they would always harvest the full 8MJ to go faster. If that's true, then it could be a clue as to why the drivers find these regulations so unintuitive. They have to make sure they are harvesting the full 8MJ to go faster. Braking later and cornering at higher speeds is an intuitive way to go faster but if it means you can't harvest the maximum, it might be slower in an energy limited formula (and perhaps even track specific). Focusing on slowing and harvesting 8MJ is how you go faster.

I have a feeling that this calculation might change on a circuit with more corners than straights. Then you just want to attack the corners as there is little to gain elsewhere.


raw data:
https://i.postimg.cc/brbddgxL/image.png

[AR3-GP]

Another interesting thing is that the harvesting isn't necessarily consistent in each corner from lap to lap. Here i show the amount of recharge for Norris and Verstappen through T1 on lap 33 and lap 34.


There can be many reasons for this. This could be deliberate due to the use of more or less superclipping, change of brake bias, side slip, or it could be variation caused by the driver using a different brake and throttle shape through the corner. This could increase or decrease the amount of harvesting that is possible. It's difficult to correlate this with laptime. In theory driver could hang in partial throttle for longer exiting the corner, and he would recharge more, but he would be slower down that straight.


As far as driving style goes, partial throttle harvesting favors drivers who can precisely judge the rear axle grip limit, so that they aren't wasting harvesting potential. In other words, you can't go to 100% throttle too soon (if the grip isn't there). If you do, you're not only wasting partial throttle harvesting potential, but also spinning the wheels and wasting deployment.

I think most drivers will benefit from a bit of coaching. Teams can track wheel spin patterns and suggest that the driver is too aggressive with the throttle. A side effect of this more gentle driving is going to be more 1 stop races imo. Reduction in speed through high speed corners for superclipping, partial throttle harvesting optimization, and other elements put the car in a less grip limited condition, which saves the tires.

[michl420]

One thing must be cristal clear. The teams will always harvest all they are allowed to, to have as much energy as possible for acceleration after the corners. When you ban just superclipping, the driver will lift and cost.
The only way to get this (slowing down before braking) away is reduced the allowed regenerartion energy.

[De Wet]

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 ?