for what purposes is the pneumatic system used on a F1 car?

[Xwang]

Hi,
I would like to know for what purposes is the pneumatic system used on a F1 car.
Is it only for pneumatic valves or it serves other systems too?

[NL_Fer]

They don’t need pneumatic valvesprings for current engine rpm’s.

[Xwang]

They don’t need pneumatic valvesprings for current engine rpm’s.

I thought the same, but I think that they have kept them anyway.
I'm wrong? Are they using springs or desmodronic systems instead?

[saviour stivala]

Yes, all four manufacturers are still using air valves.

[Dr. Acula]

They don’t need pneumatic valvesprings for current engine rpm’s.

No they don't rpm vise. But as far as i know pneumatic valve springs can be set up relatively soft compared to a mechanical spring for the same rpm/valve setup. So they end up with a few extra horses by still using them.

[Big Tea]

They don’t need pneumatic valvesprings for current engine rpm’s.

No they don't rpm vise. But as far as i know pneumatic valve springs can be set up relatively soft compared to a mechanical spring for the same rpm/valve setup. So they end up with a few extra horses by still using them.

Do they 'release' the pressure as the cam lobe rises? if there is no (or little, plus the pressure in the cylinder) resistance, it must save a huge amount of lost power in both force and friction. I had never considered this before. It only needs to stop the valve dropping off its seat until it 'follows' the close profile. Would the air be quick enough venting to do this?

[63l8qrrfy6]

They don’t need pneumatic valvesprings for current engine rpm’s.

No they don't rpm vise. But as far as i know pneumatic valve springs can be set up relatively soft compared to a mechanical spring for the same rpm/valve setup. So they end up with a few extra horses by still using them.

Do they 'release' the pressure as the cam lobe rises? if there is no (or little, plus the pressure in the cylinder) resistance, it must save a huge amount of lost power in both force and friction. I had never considered this before. It only needs to stop the valve dropping off its seat until it 'follows' the close profile. Would the air be quick enough venting to do this?

Not based on what has been published to date - they only have a PRV that opens when pressure increases from oil accumulation in the pneumatic volume. This doesn't happen every cycle.

I see what you are saying though - the pressure requirement peaks when valve acceleration is at its maximum on the opening ramp however the peak pressure inside the "air spring" peaks at maximum lift which means that there is a portion of the cycle where the air spring pressure exceeds the pressure requirement. This is just wasted power.
I am not aware of any current means of mitigating this but here could be a few practical solutions.

[63l8qrrfy6]

Yes, all four manufacturers are still using air valves.

Honda seemed to suggest they were using regular coil springs if I remember correctly ?

[gruntguru]

I would think pneumatic valve springs would still have benefits on lower speed engines. Two that come to mind are:
1. Spring force variable to suit the rpm - softer at low rpm reduces valve train friction.
2. More aggressive valve acceleration - faster opening and closing permits more area under the lift curve or shorter duration for a given lift x time area.

[Maritimer]

Gear shift is pneumatic is it not?

[kebab]

Gear shift is pneumatic is it not?

Gear shift is hydraulic if I remember correctly

[NL_Fer]

If the pneumatic pressure can vary the valve return, maybe they can use it as a variable valve timing?

[Jolle]

If the pneumatic pressure can vary the valve return, maybe they can use it as a variable valve timing?

If they would have a shift cam kind of thing, it would be hydraulic. Pneumatic is used for stuff that needs to be compressed, like indeed instead of valve springs.
So from the top of my head I can’t think of anything beyond the valves that need pneumatic power.

[63l8qrrfy6]

I would think pneumatic valve springs would still have benefits on lower speed engines. Two that come to mind are:
1. Spring force variable to suit the rpm - softer at low rpm reduces valve train friction.
2. More aggressive valve acceleration - faster opening and closing permits more area under the lift curve or shorter duration for a given lift x time area.

Regarding point 1 - the rules specify a mechanical pressure regulator with a single set pressure at the pneumatic bottle outlet. To me this sounds like they have to set the pressure for the highest engine speed plus some margin.

But then again teams are so good at going around the rules - I would not be surprised if they somehow manage to vary the pressure with RPM.

[saviour stivala]

I do not know of any system on a formula one car that uses pneumatic/pressured air system for its function apart from the engine valves return system (PVRS).
The advantages of PVRS can never be meet with a wire coil spring system.
The amount of ‘seat’ tension required to keep a wire coil sprung valve under control results in greater peak lift loading. Resulting in added stress to the entire valvetrain. A pneumatic system, sharing a common reservoir of pressure retain a more static level of force, controlling the valve effectively, without any attendant peak lift loading increase.
The previous 3.0-litre NA V10 having 40 valves and running at 18000 rpm used a 0.7 litre reservoir and a pressure of 200 bar.