2021 French Grand Prix - Le Castellet, June 18 - 20

[Just_a_fan]

Does anyone know what the air temperature is inside a tire when its out on track and up to working temperature?

Presumably it's going to be up near the temperature of the tyre, so around 100deg C I would guess. It's going to vary with heat soak i.e. the number of laps driven at race speed.

Indeed, the lag between the tyre changing temperature and the air inside doing so is what is being gamed by the teams. Heat it all up to get the official pressure. Let everything cool down a bit to cool the air and thus drop the pressure, drive gently on the out lap to keep the tyre close to the right temperature but without adding too much heat. Then make use of the time taken for the air to heat and pressures to rise during the qualifying lap.

During the race, they'll be doing something similar but playing with air temperature - blow in hot air, take the pressure, let things settle down, pressure drops a bit and you gain from the pressure drop on track. The tyre is then running slightly under pressure. We know this effect works because it affects road cars too. Rule of thumb is 0.1bar change per 10deg C change in temperature. So that's 1.45psi per 10deg C change.

[Hoffman900]

Might as well define what gasses are allowed, and just leave it there. Before & after ..

that's defined in the rules as well.

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.

Just define the minimum pressure at a fixed low temperature (or even ambient for that matter, however that may shift significantly sometimes) correlated from the minimum pressure at internal/external temp while in Q or race, and that's it.

it's the fia, they make everything overly complex and convoluted.

The simplest and most straightforward way, would be for PIrelli/FIA to fill the tyres with pure nitrogen (eliminates some variables), and ensure that pressure is normalized based on the atrophic pressure and temperature at the time of filling. Seal them with a tamper proof valve and it's a done deal.

The F1 rulebooks all look like they were written by that engineer in your firm or you’re friends with who has to make everything overly complicated, in order to show how smart they are. In reality, they just end up looking like dorks.

Albert Einstein’s Quote: “Genius is making complex ideas simple, not making simple ideas complex.” Need not apply with F1.

[godlameroso]

People often get simplicity confused with easiness.

[Just_a_fan]

The simplest and most straightforward way, would be for PIrelli/FIA to fill the tyres with pure nitrogen (eliminates some variables), and ensure that pressure is normalized based on the atrophic pressure and temperature at the time of filling. Seal them with a tamper proof valve and it's a done deal.

I'm surprised the teams aren't calling for that anyway. Actually, I can see them arguing that they need to control a safety critical issue and so they must be able to check/adjust the pressures.

Pirelli / FIA would need careful cross checking of the tyre bay to ensure a technician isn't pulling a stunt and giving one a driver a high pressure or a low pressure.

Perhaps standard wheels and tyres provided to the teams. They turn up and are allocated a set of mounted tyres on standard rims. Rim includes a TPMS unit and a temp sensor transmitting to a standard unit on each car so the teams can keep an eye on them for safety reasons - slow puncture, something rubbing, etc.

[nzjrs]

Perhaps standard wheels and tyres provided to the teams. They turn up and are allocated a set of mounted tyres on standard rims. Rim includes a TPMS unit and a temp sensor transmitting to a standard unit on each car so the teams can keep an eye on them for safety reasons - slow puncture, something rubbing, etc.

You can take those beautiful white Alpha Tauri wheels from my cold dead hands!

More seriously, I think teams will fight standardized wheels to the death. Its a big performance differentiator I believe.

[RZS10]

Wouldn't giving the teams wheels that are at a set pressure disadvantage certain teams given that all the cars 'work' the tyres differently?

[Hoffman900]

Wouldn't giving the teams wheels that are at a set pressure disadvantage certain teams given that all the cars 'work' the tyres differently?

Mid season, yes. I think the FIA / Pirelli know enough to pick winners and losers with a change like that. For a massive rule change like they have next year, they should get ahead of it, and then it’s up to the teams. IMO doing that would be a complete farce. I remember when Dunlop changed the rear tire design mid season in MotoAmerica / FIM Superbike in 2018. It took a close championship and flipped it on its head, with one bike responding way better.

Even with a very restrictive rule set in regards to tires / wheels, there are still ways in terms of set up to get them to light up and work... see Indy Car last weekend with O’Ward on the restart.

[dans79]

Does anyone know what the air temperature is inside a tire when its out on track and up to working temperature?

Presumably it's going to be up near the temperature of the tyre, so around 100deg C I would guess. It's going to vary with heat soak i.e. the number of laps driven at race speed.

Indeed, the lag between the tyre changing temperature and the air inside doing so is what is being gamed by the teams. Heat it all up to get the official pressure. Let everything cool down a bit to cool the air and thus drop the pressure, drive gently on the out lap to keep the tyre close to the right temperature but without adding too much heat. Then make use of the time taken for the air to heat and pressures to rise during the qualifying lap.

During the race, they'll be doing something similar but playing with air temperature - blow in hot air, take the pressure, let things settle down, pressure drops a bit and you gain from the pressure drop on track. The tyre is then running slightly under pressure. We know this effect works because it affects road cars too. Rule of thumb is 0.1bar change per 10deg C change in temperature. So that's 1.45psi per 10deg C change.

One thing I think could be possible, would be heat soaking the tires when full with air and then releasing the excess air/nitrogen to get them down to the minimum pressure. then When they aren't in their blankets, they are losing internal air temperature and thus pressure.

I could see it potentially being possible to lower/regulate the internal temperature, by using the brake ducts. By messing with blanking. they could probably let some amount of air pass through directly to the rims providing a cooling effect. They could probably do the same thing with the air used to cool the brakes (now hot). by playing with the blanking they could basically mix the different types of air blowing through the rims and thus potentially regulate the internal air temperature/pressure.

[Just_a_fan]

Perhaps standard wheels and tyres provided to the teams. They turn up and are allocated a set of mounted tyres on standard rims. Rim includes a TPMS unit and a temp sensor transmitting to a standard unit on each car so the teams can keep an eye on them for safety reasons - slow puncture, something rubbing, etc.

You can take those beautiful white Alpha Tauri wheels from my cold dead hands!

More seriously, I think teams will fight standardized wheels to the death. Its a big performance differentiator I believe.

We know the wheels are performance items. Look at the fun Mercedes had with varying designs a few years ago trying to sort the rear tyres.

[Just_a_fan]

I could see it potentially being possible to lower/regulate the internal temperature, by using the brake ducts. By messing with blanking. they could probably let some amount of air pass through directly to the rims providing a cooling effect. They could probably do the same thing with the air used to cool the brakes (now hot). by playing with the blanking they could basically mix the different types of air blowing through the rims and thus potentially regulate the internal air temperature/pressure.

No "could" involved. They're doing it now in various ways. You only have to look at the routing of air through the wheel "drum" to see that much of it isn't cooling the brakes. It's being used for blowing and temperature control of the rims. Look at the dimpled inner faces of the wheels being used by teams to control rim and thus air/tyre temps.

[dans79]

I could see it potentially being possible to lower/regulate the internal temperature, by using the brake ducts. By messing with blanking. they could probably let some amount of air pass through directly to the rims providing a cooling effect. They could probably do the same thing with the air used to cool the brakes (now hot). by playing with the blanking they could basically mix the different types of air blowing through the rims and thus potentially regulate the internal air temperature/pressure.

No "could" involved. They're doing it now in various ways. You only have to look at the routing of air through the wheel "drum" to see that much of it isn't cooling the brakes. It's being used for blowing and temperature control of the rims. Look at the dimpled inner faces of the wheels being used by teams to control rim and thus air/tyre temps.

I ways saying could, because I don't have access to enough thermal dynamic and airflow data to try and even make an educated guess as to how much benefit it might yield.

I mean lots of things are theoretically possible. they could have a fluid switch so when traveling at safety car speeds the only thing hitting the rims is hot air from brakes.

[dans79]

Here's a nice overview video for those who don't want to dig into all the intricate details.

[Singapore2008]

That are a lot of ifs and presumptions made.

[maxxer]

Perhaps standard wheels and tyres provided to the teams. They turn up and are allocated a set of mounted tyres on standard rims. Rim includes a TPMS unit and a temp sensor transmitting to a standard unit on each car so the teams can keep an eye on them for safety reasons - slow puncture, something rubbing, etc.

You can take those beautiful white Alpha Tauri wheels from my cold dead hands!

More seriously, I think teams will fight standardized wheels to the death. Its a big performance differentiator I believe.

I would quit watching F1 if because of --- tires they need standard rims rather watch indycar or rally then

[henry]

More seriously, I think teams will fight standardized wheels to the death. Its a big performance differentiator I believe.

I hope not. Standard wheels come in next year as far as I know.