What gas is used to fill F1 tyres?

[Rhino]

I watched the past weekend's Monaco GP and noticed that each time a car hit the wall and the tyres burst, a small explosion occurred. This tells me that there is some form of combustible gas in the tyres. Just out of interest, does anybody know what type of gas is used by F1 teams and why? I initially though of nitrogen (as is often used in road tyres), but nitrogen is an inert gas which will not explode. What advantages would some super tyre filling gas have over nitrogen or normal air?

[hardingfv32]

Nitrogen or air per the rules.

Could it be the mag wheel igniting?

Brian

[marcush.]

how much magnesium is in current wheel alloys? I´d think the potential for self igniting is rather low.Magnesium itself is only igniteable in ´form of powder or chips..so maybe the grinding of the wheel on the hub or more so the carbon brake disc is exploding when subject to the loads in the accident?

[Shrek]

i read somewhere that Ferrari put 52% Tetrafluoroethane, 44% Pentafluoroethane and 4 % Trifluoroethane in the tire, don't know if it is really true though.

[DaveKillens]

The FIA technical regulations for 2011 state :

12.7 Tyre gases :
12.7.1 Tyres may only be inflated with air or nitrogen.
12.7.2 Any process the intent of which is to reduce the amount of moisture in the tyre and/or in its inflation gas is forbidden.

http://argent.fia.com/web/fia-public.nsf/055CFD424959A061C1257870003A02F0/$FILE/1-2011%20TECHNICAL%20REGULATIONS%2008-03-2011.pdf

I'm pretty comfortable with the definition of "nitrogen" but since the tech regs do not specifically define "air", it is one more of those crazy regulations that are deliberately kept open to interpretation.

So the best I could come up with is

air [ɛə]
n
1. (Chemistry / Elements & Compounds) the mixture of gases that forms the earth's atmosphere. At sea level dry air has a density of 1.226 kilograms per cubic metre and consists of 78.08 per cent nitrogen, 20.95 per cent oxygen, 0.93 per cent argon, 0.03 per cent carbon dioxide, with smaller quantities of ozone and inert gases; water vapour varies between 0 and 4 per cent and in industrial areas sulphur gases may be present as pollutants

[hardingfv32]

1) Based on the weight of the F1 wheel I have it is 100% mag.

2) Air: Air must be inhaled by the team's technical director from any of the tires used during the race meeting at the request of the FIA.

Brian

[Belatti]

2) discards the use of bottled farts to fill the tires

[Ciro Pabón]

Could it be the brake pads? I mean, the cause of the fireball you saw. They are red hot and they will pulverize easier than rims.

Or maybe it was dihydrogen monoxide.

This is a very dangerous substance. Colorless, odorless, tasteless, it kills uncounted thousands of people every year by accidental inhalation. When slightly heated, it transforms into a gas that can burn a human being in seconds.

DHMO is also the MAJOR component of acid rain and causes electrical failures and decrease the efficiency of brakes AND tyres. DHMO has been found in both.

Worse yet, when gasoline and DHMO are put in contact, it has the power to spread the fire. I fail to comprehend why FIA has not put regulations in place to get rid of it. Some teams even use it to enhance the effectiveness of refrigeration systems! A substance that when inhaled in small quantities is mortal, is kept hot and inches away from the driver.

Even more dangerous is the fact that DHMO is an universal solvent, as the mythical "alkahest" of alchemists. It can dissolve anything!

FIA actually forbid people to use gases helpful in extracting DHMO from tyres. I say we should organize a protest, specially because CONTAMINATION OF DHMO IS REACHING EPIDEMIC PROPORTIONS!

As DHMO has been detected in Red Bull, I suspect a conspiracy between them and FIA.

It has also been detected in Monaco in large quantities, even around the track.

Huge amounts of dihydrogen monoxide have been found in almost every pool, stream, lake, and reservoir in Monaco today. This pollution is global, and the contaminant has even been found in Antarctic ice. Few persons are free of DHMO in their bodies and it even can be transmitted by nursing a baby.

If ingested by an engine it can break a block or crack a piston in less than a second.

So, I suspect DHMO.

Companies dump waste DHMO into rivers and the ocean, and nothing can be done to stop them because this practice is still legal!

The number of addicts to DHMO is incredibly large. Say no to DHMO. Let's stop the DHMO cycle!

It's worst that a can of farts.

[Muulka]

how much magnesium is in current wheel alloys? I´d think the potential for self igniting is rather low.Magnesium itself is only igniteable in ´form of powder or chips..so maybe the grinding of the wheel on the hub or more so the carbon brake disc is exploding when subject to the loads in the accident?

Magnesium is highly flammable in the form of a metal strip at least, and I have seen videos of a rally car being set alight by its magnesium wheels. It's aluminium that you're thinking of probably.

Anyway, I think that it's mostly nitrogen that they put in F1 tyres- all sorts of good things come from nitrogen- nitrates, speed around a corner....

[Rhino]

I would guess that, if the explosions were caused by the Mg rims, the colour of the flame would be more white. The mini explosions In Monaco were more yellow/orange in colour. Never thought of the visual effect a very high temperature disc would have when it disintigrates. It is a plausible explanation.

[hardingfv32]

Is your screen/monitor rendering accurate colors? Is the camera responding correctly to the sudden change in light exposure?

Brian

[alelanza]

When slightly heated, it transforms into a gas that can burn a human being in seconds.

This doesn't make sense to me, unless your definition of 'slightly' differs from mine by quite a margin.

[Lurk]

how much magnesium is in current wheel alloys? I´d think the potential for self igniting is rather low.Magnesium itself is only igniteable in ´form of powder or chips..so maybe the grinding of the wheel on the hub or more so the carbon brake disc is exploding when subject to the loads in the accident?

Magnesium is highly flammable in the form of a metal strip at least, and I have seen videos of a rally car being set alight by its magnesium wheels. It's aluminium that you're thinking of probably.

I did some research on F1 wheel 2 month ago because I was asking me of what it is made exactly.
I must say that there should be something else because mag wheels don't self ignite. They are sufficiently safe to be used on road car. They even use magnesium alloys to make some engine parts. Maybe something on the rim catch fire and then the rim ignite? Or maybe the guy had a puncture and ran on the wheel which heat a lot at the contact point with the road?

That said, magnesium fires are very difficult to extinguish and in some Great Britain races mag wheels are forbidden because of that.

1) Based on the weight of the F1 wheel I have it is 100% mag.

Forged magnesium alloy AZ70 or AZ80. AZ70 is 7% Aluminium, 0% Zinc, 93% Magnesium and AZ80 is 8% Aluminium, 0% Zinc, 92% Magnesium.
It is specify on the appendix for technical regulations.


Tyres were also filled with carbon dioxide some years ago. It was pretty effective.

[Belatti]

Few persons are free of DHMO in their bodies ...

And that would be... skinny models? Mr Burns?

[richard_leeds]

The FIA technical regulations for 2011 state :

12.7 Tyre gases :
12.7.1 Tyres may only be inflated with air or nitrogen.
12.7.2 Any process the intent of which is to reduce the amount of moisture in the tyre and/or in its inflation gas is forbidden.

http://argent.fia.com/web/fia-public.nsf/055CFD424959A061C1257870003A02F0/$FILE/1-2011%20TECHNICAL%20REGULATIONS%2008-03-2011.pdf

That rule seems contradictory. I thought the main reason for using nitrogen was because bottled gases are dry so that contradicts 12.7.2.

Dry gases are less susceptible to pressure changes than damp gases. Having identified the need for a dry bottled gas, Nitrogen is used because it is the cheapest and inert.

Some folk say nitrogen helps the tyres last longer because the reduced oxygen reduces oxidisation of the tyre lining, plus nitrogen molecules are bigger, hence less likely to seep through the rubber. Also less water reduces corrosion of the wheel. However those issues of longevity are irrelevant for the short lifespan of an F1 tyre.

....

For road cars.... when the tyre is put on the wheel it is full of air at 1 bar. If it is pressurised to 2.5 bar, then you are adding extra 1.5 times the tyre volume, hence the tyre contains 60% dry nitrogen and 40% wet air. Air at 20C with 75% humidity contains 13g water per m3, the dew point is 15C. This means water droplets will start to form in your tyre at 15C.

Dilute the tyre down to 40% air gives 5 g/m3, which has a dew point of 0C. So water droplets won’t form until it gets frosty.

Before you get too worried, a tyre only has 11 litres of air http://www.club80-90syncro.co.uk/Syncro ... ulator.htm

So the amount of water in a tyre when filled with normal air at 13g/m3 is just 0.143g of water, ie 0.143ml. Hardly worth worrying about.

As for the oxygen molecules, the air is 79% nitrogen anyway. When those oxygen molecules leak or oxidise with the tyre lining you replace them with 79% nitrogen, so for every 100 molecules of leaking oxygen, you only put 21 back.

...

The influence of humidity on expansion is an interesting one, I’ll let someone else take up that baton.