Just an idea: can one control temperature of the tires by braking the front tires while burning out the rears at speed? What would the ideal brake bias and throttle be at safety-car speeds?
Now that TC is banned, I suppose the drivers can do burnouts whenever they want, and at nearly any speed (of course, they can't burn out at 160 or 180 mph, nor would they want to ). But they absolutely can at safety car speed, and I don't see any reason why it wouldn't help the rear tires get back up to temp. Don't know if this helps, it's just the first thing that came to mind! Cheers!
A burn-out also only heats up the surface of the tire, which isn't ideal for grip and wear. It helps getting traction in the start, though, which is why you see drivers (Alonso in particular) doing burn-outs on their way to the start grid (in the days of traction control, drivers had a button on the steering wheel to override TC).
The best way to heat up tires behind the safety car is to leave a gap to the car in front and then drive one or two bends near full race speed (and then repeat the procedure). But this is dangerous, and frowned upon by the race stewards.
Racing tires get up to temperature pretty quick. It may only take one or two hard, long corners at racing speed to get the carcass of a road race tire heated up. If you've ever picked one up, you will have noticed that F1 tires have amazingly little mass. Less mass means faster heating. The side walls are paper thin, the body has very few plies, and the tread can't be more than about a quarter inch (6.5mm) thick. This is also why they get punctures just running over a small piece of debris.
Prior to putting the tires on the car, they are also usually pre-heated with tire warmers. Race tires typically want to run at temps somewhere between 210degF and 230degF. That is the temp where most race tire rubber compounds produce their highest grip, or coefficient of friction (Mu). It is important not to overheat, or even put the tire thru too many heating/cooling cycles, because it can adversely (and permanently) alter the mechanical properties of the rubber compound. A brand new tire (a "sticker") will also behave differently than a slightly used tire (a "scuff"). This is because tire rubber compounds change after they have gone thru a heating/cooling cycle. This is done once during manufacture and is called "vulcanizing". It can happen a second time (to a lesser degree), during the tire's first run, but the tire compound is usually pretty stable after that. Scuffing tires not only helps to stabilize their mechanical properties, but it also helps to remove the very outer layer of rubber on the tread which may be contaminated with chemicals like mold release from manufacturing.
One reason a tire experiences heating is that it is not 100% efficient as it rolls, even in a straight line. The efficiency loss is due to a phenomena in the tire structure called hysteresis, and that hysteresis (kinetic energy) loss is converted to heat. The old bias ply construction tires had higher hysteresis losses than modern radial ply construction tires, so they tended to produce more heat, and thus heated up faster.
And finally, the most important reason for maintaining consistent, controlled tire temperatures, is that tire inflation pressures will vary with temperature. For a ride height/pitch/roll sensitive ground effect chassis, like an F1 car, much of the suspension travel is produced in the tire sidewall flex. The tires are in effect a pneumatic spring at each corner of the chassis. A change in tire pressure as small as 1 psi can produce a big change in the "spring rate" of the tire. I would guess that an F1 tire probably has a spring rate of around 1500 lbs/in and an inflation pressure of about 25 psi. So you can see that changes in tire pressure, due to tire temperature changes, can have a significant impact on handling.
I would have to agree with Jersey Tom, smoking the rears only would likely upset the car's handling balance.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
I have heard about 17 to 19 psi of inflation pressure (very old data, 1997).
Beyond the value, these cars are very very sensitive to pressure modification as riff_raff said. For a given spring rate setup for an X track you could modify at least 1 psi.
Thats why tires are inflated with Nitrogen instead of simply air. Air contains humidity depending on weather and so its a bit more difficult to predict the gas behaviour. Bottled nitrogen is closer to a "perfect gas" and thus the ecuation is simple (P*V=R*T)
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F1 tires are indeed inflated with dry nitrogen gas. But the main issue with the moisture content of air is that the tires actually run hot enough to cause this moisture to turn to steam. When that happens the inflation pressure will change radically.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
You must have missed the part where refrigerants are the inflation gas; combined with those cute wheel covers, to manage much of what is going on in those tyres, of that red car!
Check out the court procedings of last year...................
). But they absolutely can at safety car speed, and I don't see any reason why it wouldn't help the rear tires get back up to temp. Don't know if this helps, it's just the first thing that came to mind! 