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

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
Xwang
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for what purposes is the pneumatic system used on a F1 car?

Post by Xwang » Sat Jun 29, 2019 4:05 pm

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

Post by NL_Fer » Sat Jun 29, 2019 5:39 pm

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

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

Post by Xwang » Sat Jun 29, 2019 5:44 pm

NL_Fer wrote:
Sat Jun 29, 2019 5:39 pm
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
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Re: for what purposes is the pneumatic system used on a F1 car?

Post by saviour stivala » Sat Jun 29, 2019 7:09 pm

Yes, all four manufacturers are still using air valves.

Dr. Acula
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Re: for what purposes is the pneumatic system used on a F1 car?

Post by Dr. Acula » Sat Jun 29, 2019 10:50 pm

NL_Fer wrote:
Sat Jun 29, 2019 5:39 pm
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.

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

Post by Big Tea » Sat Jun 29, 2019 10:56 pm

Dr. Acula wrote:
Sat Jun 29, 2019 10:50 pm
NL_Fer wrote:
Sat Jun 29, 2019 5:39 pm
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?
One test is worth a thousand expert opinions

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

Post by Mudflap » Sat Jun 29, 2019 11:33 pm

Big Tea wrote:
Sat Jun 29, 2019 10:56 pm
Dr. Acula wrote:
Sat Jun 29, 2019 10:50 pm
NL_Fer wrote:
Sat Jun 29, 2019 5:39 pm
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.
How much TQ does it make though?

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

Post by Mudflap » Sat Jun 29, 2019 11:34 pm

saviour stivala wrote:
Sat Jun 29, 2019 7:09 pm
Yes, all four manufacturers are still using air valves.
Honda seemed to suggest they were using regular coil springs if I remember correctly ?
How much TQ does it make though?

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

Post by gruntguru » Sun Jun 30, 2019 3:55 am

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.
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Maritimer
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Re: for what purposes is the pneumatic system used on a F1 car?

Post by Maritimer » Sun Jun 30, 2019 5:36 am

Gear shift is pneumatic is it not?

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

Post by kebab » Sun Jun 30, 2019 5:43 am

Maritimer wrote:
Sun Jun 30, 2019 5:36 am
Gear shift is pneumatic is it not?
Gear shift is hydraulic if I remember correctly

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

Post by NL_Fer » Sun Jun 30, 2019 10:53 am

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

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

Post by Jolle » Sun Jun 30, 2019 10:57 am

NL_Fer wrote:
Sun Jun 30, 2019 10:53 am
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.

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

Post by Mudflap » Sun Jun 30, 2019 11:07 am

gruntguru wrote:
Sun Jun 30, 2019 3:55 am
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.
How much TQ does it make though?

saviour stivala
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Re: for what purposes is the pneumatic system used on a F1 car?

Post by saviour stivala » Sun Jun 30, 2019 11:10 am

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.