Ferrari SF-26

[hollus]

Revs typically only vary by +\- 20% over your 11000 average, it should work mostly the same at all times.
I think if this if clever in isolation, or a direct byproduct of the new “always charging” 2026 rules making it desirable to have engine on at almost all times. This will now work with more gas under braking and in the initial and middle part of the corner…

[NYHC]

Will the higher exhaust gas speed through the limited opening also increase the exhaust gas speed in the whole system and lead to higher revs of the turbo? Which would also align with the better starts?

[AR3-GP]

Will the higher exhaust gas speed through the limited opening also increase the exhaust gas speed in the whole system and lead to higher revs of the turbo? Which would also align with the better starts?

No it doesn't work like that. There is a very small power loss from this solution. The exhaust plate increases the work required to push the exhaust out.

[Stu]

Will the higher exhaust gas speed through the limited opening also increase the exhaust gas speed in the whole system and lead to higher revs of the turbo? Which would also align with the better starts?

I would say not. The constriction will alter the gas speed locally (like the ‘thumb over a hose pipe’ analogy), but if not carefully designed it would be easy to increase the back pressure to the turbo reducing it’s efficiency - with a turbo system it is VERY important to manage the pressure differential seen at the compressor and turbine. Ferrari have fitted the smallest allowable tailpipe diameter (or close to it) to maximise the effect of the aero part of the device, it then looks as though they have used close to the maximum size tailpipe for the ‘cup’ section that is open. This will be the critical element in making the whole device work.
The small tailpipe will increase the gas speed, the ‘device’ will create a rapid expansion; the change of CSA will broaden the exhaust plume across the underside of the rear wing.
It will also create a small amount of downward thrust itself (like a Top Fuel dragster), which may be beneficial at starts and very low speeds but, I would suggest, this is a ‘nice’ side-effect rather than the main purpose of the design.

[bananapeel23]

The internet says that exhaust gas volume and velocity scales linearly with engine revs. I wonder if that could potentially destabilize the blown rear-end when, say, downshifting in the middle of a corner?

These are seamless shift gearboxes. Revs will drop a bit, but the exhaust gasses won't stop flowing entirely, especially with the recharging characteristics of these engines. Generally you also don't tend to downshift mid corner very often, especially not at the very low speeds where this exhaust blowing will make a significant difference.

[PlatinumZealot]

It's not a blown diffuser where the exhaust is directly influencing the throat veleocity and thus peak pressure of the diffuser. In this case the exahaust is just adding some energy to the diffuser wake and helping the extraction a little bit more, and also helping the rear wing. Remember this is a opportunitistic solution that's making do with "scraps available." it's not a big gun solution like the double diffuser or F-duct.

[nico5]

Revs typically only vary by +\- 20% over your 11000 average, it should work mostly the same at all times.
I think if this if clever in isolation, or a direct byproduct of the new “always charging” 2026 rules making it desirable to have engine on at almost all times. This will now work with more gas under braking and in the initial and middle part of the corner…

The rule change from:
>ICE torque varies with driver's power demand,
to:
>OVERALL torque varies with driver's power demand
is essentially an invitation to run ICEs at maximum load (or what is allowed by the FIA's minimum negative torque equation) at all times.
That is also probably why they lowered max fuel flow from 100kg/hr to 70kg/hr, this way they can run the race with about 90kg of fuel (similar to 2025) and run still have as much harvesting as they can.
It's kind of surprising only Ferrari thought about maximising exhaust blowing for aero purposes given this was built into the regulations from day 1.

[vorticism]

Any constriction is probably minimal.

[bluechris]

With all this scenario's with the ICE almost always in high rev's working condition, the 70kg fuel, will last a race?

[AR3-GP]

With all this scenario's with the ICE almost always in high rev's working condition, the 70kg fuel, will last a race?

There is no fuel capacity limit.

[bluechris]

With all this scenario's with the ICE almost always in high rev's working condition, the 70kg fuel, will last a race?

There is no fuel capacity limit.

You are right, sorry my mistake, i messed the fuel flow with the tank capacity.

[Andi76]

A CfD Simulation i found from Ferraris Upside Down Wing from opening, open and closing again:

[bananapeel23]

With all this scenario's with the ICE almost always in high rev's working condition, the 70kg fuel, will last a race?

In practice you won't see a significant reduction in fuel consumption over the race distance, even if the mass flow limit (energy flow now) has been reduced by ~30%. Real world fuel consumption might be reduced on the order of 15% or so due to the slightly longer races and revving where previous cars would be idle.

This arguably makes these regulations even more baffling than they already were. The FIA would get higher performance cars by increasing energy flow and banning or significantly reducing the scope on-throttle recharging, which would increase real world efficiency slightly over the entire PU operating window, even if it would reduce peak efficiency.

I still suspect that we will end up seeing energy flow bumps for 2027 if the first few GP:s turn out to be a disaster, while limits on on-throttle recharging and peak deployment will likely be imposed fairly quickly to encourage saving of electrical power.

I would expect peak deployment in race conditions to end up mostly limited at 250 or 200 kW, with an exception for overtake, which will likely stay at 350 kW. As it currently stands overtake has no purpose, as no car has any energy left once it hits 290 km/h. If you get more MGU-K power in the acceleration phase instead, you can afford to take alternate lines, then power out of corners more quickly and hopefully battle for position into the braking zone. It would produce much more "natural" (really more like natural looking) racing.

[venkyhere]

A CfD Simulation i found from Ferraris Upside Down Wing from opening, open and closing again:

https://postimg.cc/JGc4T0bb
https://postimg.cc/TySRyDXt
https://postimg.cc/GTPrSgTf
https://postimg.cc/183PJHRm
https://postimg.cc/GBZC3nF9
https://postimg.cc/QVg3DPHN
https://postimg.cc/nj8ybYxp
https://postimg.cc/QVqdmVgW
https://postimg.cc/rDDyqJBn
https://postimg.cc/WDr2k4bh
https://postimg.cc/WDr2k4bh

Maybe this generic double-element wing profile used in the CFD is to only give a crude idea, since the actual wing's mainplane and the double-element flaps are shaped very different to this, angled very different to this, etc.

[sucof]

A CfD Simulation i found from Ferraris Upside Down Wing from opening, open and closing again:

https://postimg.cc/JGc4T0bb
https://postimg.cc/TySRyDXt
https://postimg.cc/GTPrSgTf
https://postimg.cc/183PJHRm
https://postimg.cc/GBZC3nF9
https://postimg.cc/QVg3DPHN
https://postimg.cc/nj8ybYxp
https://postimg.cc/QVqdmVgW
https://postimg.cc/rDDyqJBn
https://postimg.cc/WDr2k4bh
https://postimg.cc/WDr2k4bh

Maybe this generic double-element wing profile used in the CFD is to only give a crude idea, since the actual wing's mainplane and the double-element flaps are shaped very different to this, angled very different to this, etc.

Indeed. Add to that that Ferrari will surely design a shape that is optimised for this solution, which can be very different.