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In this month's Racecar Engineering magazine, in an article about the new Pirelli tires, Ross Brawn says that at some circuits (Catalunya, specifically) one side of the car's tires are warm and the other side's tires are cold. I was wondering how, or if, a car's set-up can counteract this phenomenon. I mean, what can an engineer do to get ALL of the tires in the same temperature range. Thanks guys!

Short answer is weight balance spring rate spring preload. Long answer I will leave to JT. If this were a good tire supplier the compounds would be different on either side of the car.

MrCodyWeston wrote:In this month's Racecar Engineering magazine, in an article about the new Pirelli tires, Ross Brawn says that at some circuits (Catalunya, specifically) one side of the car's tires are warm and the other side's tires are cold. I was wondering how, or if, a car's set-up can counteract this phenomenon. I mean, what can an engineer do to get ALL of the tires in the same temperature range. Thanks guys!

Probably not much if anything of significance. Heat is so dominantly affected by load (deflection really) and speed. Speed left to right is effectively identical. That leaves deflection. If tires on one side of the car are worked on average appreciably more than the other.. they'll run hotter. If temperature was really the end-all-be-all you could maybe bleed air out of the one side to see if you can run them hotter. Maybe you can get some small effect from some suspension bits - but then you're getting secondary effects rather than primary. Temperature is the not the end game anyway. It's not so dominant that you can throw away everything else in your setup - or teams would and not have this issue.

In extreme cases, the best solution would be to have different left and right side tires - as you find in NASCAR.

Being an engineer is about understanding which items are in your control, which aren't, which you sweat and which you don't.

Would it be possible to run different pressures in either side?

More pressure = less deflection of tire = less heat?

Nando wrote:Would it be possible to run different pressures in either side?

More pressure = less deflection of tire = less heat?

That would be the corollary of less pressure = more deflection = more heat, yes.

There's no magic to it, just a question of what you can do, what you're gaining and what you're throwing away. Start playing with air pressure to affect temperature... how much does that change in tire spring rate now affect your ride heights and hurt your aero? How does that change in carcass stiffness affect your tire footprint and hurt grip? How much does an increase in stiffness affect your tire load variation and ride-related mechanical grip?

As I said, if temperature were the end game it would be easy.

in the end -one of the two tyres will give up sooner -the cold one may have lost all tread the hot one cooked to death..you could hope they end their lives in a similar way in terms of grip available at the same time....but that´s not going to happen.
So you will compromise or tweak your setup to help both sides ...and that will lead to a car not symmetric ?

Thanks guys! And JT, are you some sort of Race Engineer? Your answers definitely make you sound like one...

I'm an engineer in pro level American racing, yes.

Jersey Tom wrote:I'm an engineer in pro level American racing, yes.

Cool man. NASCAR I take it?

In general, the hotter tire will have better adhesion, do more work and get hotter yet than the cooler tire. With this positive feedback system, you can push it in here but it pops out there. Wedge is probably the most common example of getting a cooler tire to work more, but only on one diagonal.

olefud wrote:In general, the hotter tire will have better adhesion, do more work and get hotter yet than the cooler tire. With this positive feedback system, you can push it in here but it pops out there.

Not necessarily, I think. The "positive feedback" you mentioned is likely to be stabilised somewhat by the fact that the effective tyre damping coefficient reduces as the temperature rises (all within limits, of course).

olefud wrote:Wedge is probably the most common example of getting a cooler tire to work more, but only on one diagonal.

I'd argue that the effects of wedge (which is as applicable to road course cars as oval, really) can be explained purely by "traditional" methods without even touching on temperature.

Jersey Tom wrote:

olefud wrote:Wedge is probably the most common example of getting a cooler tire to work more, but only on one diagonal.

I'd argue that the effects of wedge (which is as applicable to road course cars as oval, really) can be explained purely by "traditional" methods without even touching on temperature.

We may not differ on this. My point was that adjustments such as wedge and roll stiffness can rearrange the weight distribution/transfer while not increasing the total weight available. Thus, within limits, the work done, and associated temperature, can be affected at the tires, but only diagonally or at an end rather than side to side.

This isn’t too profound so I suspect it may be “traditional”.

Is there sensors or some other device readily available that can track the tyre temp real time and display that? Does F1 currently do this? Or is there some kind of reg preventing this level of information gathering? I would have thought a basic thermal sensor strategically placed facing each tyre would give some kind of relevant data.

It seems simple enough, that it you knew the tyres were getting in the right zone, or weren't for the matter, possibly adjusting the driving style may help this? Or am I way off here.

Cam wrote:Is there sensors or some other device readily available that can track the tyre temp real time and display that? Does F1 currently do this? Or is there some kind of reg preventing this level of information gathering? I would have thought a basic thermal sensor strategically placed facing each tyre would give some kind of relevant data.

It seems simple enough, that it you knew the tyres were getting in the right zone, or weren't for the matter, possibly adjusting the driving style may help this? Or am I way off here.

I'm reasonable sure, that teams in F1 will use sensors (IR) to measure tyre surface temperature in real time, as well as tyre pressure.
Most tyre pressure sensors will also measure the air temperature inside the tyre at the same time.
Tyre surface temperature changes very quickly in both directions, so it's not a true indication of tyre bulk temperature, but useful nonetheless.

To measure the temperature inside the tyre construction would require specifically prepared tyres, so I think, this while technically possible is not done widely.
Maybe Pirelli does this during some of there tests with specific produced/prepared tyres.

At times, during the TV broadcast, you will hear race engineers talking to drivers about "tyre temperature".
I seem to remember, that Rosberg was reminded a couple of times, to "look after his rear tyres" because the team could see that tyre temp. was to high ( for their liking).

http://www.thermoteknix.com/content/eng ... CETECH.pdf