Thoughts on 2012 tyres?

[raymondu999]

Pirelli tested their tyres on the 2010 Toyota

2010 Renault, you mean.

and I thought it would have been logical, blatantly obvious even, to design the 2012 car that mimicked the ratio of front and rear aero balance and centre of pressure of the 2010 Toyota for an edge in maximizing tyre performance.

How though, when you don't even know the aero balance and center of pressure of the 2010 (corrected) Renault? Only Renault has that data - and even then, the car had one of the bigger double diffusers - how do you mimic that? I don't think it's as clear-cut as just getting the same aero balance with reduced frontal df - I think the sheer amount of raw downforce the car produced at the rear would have to be closely mimicked too.

[wunderkind]

Marcush,

I agree with all your points. Thanks.

[Richard]

I recall that the test car was modified to mimic 2012, such as removing the DDD. It wa robaby alfwy between two stools, So I doubt the test car could be replicated by a 2012 team.

[wunderkind]

I recall that the test car was modified to mimic 2012, such as removing the DDD. It wa robaby alfwy between two stools, So I doubt the test car could be replicated by a 2012 team.

Where are the 2012 cars on rear downforce in comparison to the 2009 and 2010 cars? I would have thought the engineers would have clawed back a big chunk of downforce lost by the banning of the DDD since then.

[turbof1]

I don't know. But all teams knew Pirelli tested their tyres on the 2010 Toyota and I thought it would have been logical, blatantly obvious even, to design the 2012 car that mimicked the ratio of front and rear aero balance and centre of pressure of the 2010 Toyota for an edge in maximizing tyre performance. This point probably evaded most of the teams as they did not realize the difficulty in making the Pirellis work until the second or third pre-season test of the 2012 season. But I thought by the third race of this season, all the teams would have already tried to modify their cars to mimick the 2010 Toyota to get on top of the tyre situation.

That's impossible. There are a number of either non-mimickable factors or otherwise unknown factors that have an effect on the car:
-2012 downforce levels at the back are lower then the 2010 toyota.
-Nothing is known about the weight distribution of the toyota, while current f1 cars have an almost fixed weight distribution
-There is no data about the suspension. Granted you can roughly get an idea what effect the toyota suspension has on the tyres, but you can never know it precisely
-The toyota was actually designed for Bridgestone tyres and isn't at all suited for pirelli's. mimicking the toyota would be unwise to do.

... Now that I think of it, the 2010 toyota was never used as a pirelli test car. The 2009 car was.

Yes, I stand corrected, pirelli used the 2009 Toyota to develop the tyres for this season. But I think the critical figures of the testcar such as weight distribution, front and rear downforce were made known to all the teams so they had a good idea of what they were going to work with. Furthermore, teams could have looked at their own data from 2009 to see what they could add to the design of the 2012 package.

The levels of downforce between 2009 and 2012 are different. But I would have thought starting with the aero balance ratio similar to a 2009 Toyota would be a good basis. The 2009 Toyota was designed to run on Bridgestones as you said. But the suspension rules have not changed a great deal since 2009 and as the tyre situation is mostly temperature related, I would think aero load would be the most crucial factor.

IMO even if you have the data, would it not still be difficult to get spot on with the tyres? I mean if you get the data you obviously can get an idea, but mostly how the toyota reacts on it. Your current car obviously is going to react very different on it and is in many ways so much different then the toyota. Therefore, it's more about understanding the tyres themselves then a 3 year old car.
I do suspect the following: tyre performance would have been massively bad on the toyota, never been able to get into the working temperature. We must not forget that when Pirelli "tests" the tyres it is just to see if they can notice the changes they made. The tyres are certainly not made for the toyota. If I am correct Pirelli themselves admitted they do not understand how to get and stay in the working interval of the tyres.

[Jersey Tom]

as the tyre situation is mostly temperature related

You sure about that?

If I am correct Pirelli themselves admitted they do not understand how to get and stay in the working interval of the tyres.

If that is indeed the case it's pretty simple - if the cars can't generate enough work to get there, Pirelli hasn't matched their tread compounds well to the series.

[marcush.]

excuse me
but what is the reason for pounding around with a test mule doing tyre tests? You will retrieve some data from it but would you be sure of safety issues ? not at all.
I´m pretty sure tyre tresting will inevitably lead to a performance development into the direction suiting the test hack and its driver and test track that is.
I just cannot imagine Pirelli and its test crew would deliberately develop the tyre NOT to suit their hack...it does not make any sense.
As for real world data blurred by environment -or having reproduceable test environments- I´ll give two example from my experience:
I work in Temperture validation for full vehicle development.I have access to Simulation (CDAdapco) ,we do full vehicle testing on the road ,on test tracks (IDIADA) or in climate windtunnels or Climate chambers.
The truth is: the biggest deviations are to be found with Simulation when you get incredibly big discrepancies just due to people taking wrong decisions in their calculations .The real world test will retrieve all temps as is. surely influenced by uncontrollable environment influences but REAL...like tartmac temps,wind ,height over sea level driver input and what have you .
Then you got the test track with the simulated loads ( input by a braketrailer) giving good correlation to real world driving even though the environmental conditions are much more controllable and you get the climate windtunnel data which again highlights the same but without the tarmac temps added...
My experience says : you just cannot do without any of them .The main right or wrong is really finally ticked off on the road
If you know your beast and have built up your database ...heck you might even do your test in your backyard and come up with a entirely valid judgement.
But all the non real world tests and sims produce results completely out of range of what happens in reality in certain areas -and this ,my experience totally correlates to what we see in Formula 1. Theory is fine testing on rigs or in the lab is fine ,but it takes you only that far ...real world does add a factor that potentially throws all your results severely out of the window and I think exactly this is the problem with "understanding "the tyre ..separating the "noise" from your tyre model.

[Jersey Tom]

I'll still take rig / lab over live data by a wide margin. Without getting too into it, the other aspect of "live environment" testing is getting data which is very sparse.

[marcush.]

Tom ,I hear you ,but don´t you think taking a set of data derived from a rig is useless crap when the information you get is so far from reality that putting a fly on the rear wing gurney will throw all your data out of proportion?
In case your data produces realiable results in on track performance -that´s perfect...but looking at Formula 1 these days it does not look like the teams have any reliable data base to produce a working tyre model.

If it´s impossible to separate the tyre characteristic from noise in real world testing -i fear the tyre charecterisation is a pink elefant not worth chasing as you either hit or miss.So you just concentrate on optimising temperature rise and distribution and look after your pressures and that ´s about it instead of putting so many equations behind the tyre understanding and forget the cloud of uncertainty you are discribing with all this.
I often have the feeling with the sims I happen to have access to: hey i don´t need 100hrs of calculation time to know what will happen ...

[superdread]

The product I think can be described a bit more simply than the above. Comes down to company knowledge / resource / experience. Tire design is all about trade offs. I'll draw up an example here...

(Picture from last page.)

No surprise to anyone who has any experience with tires - race tires or consumer. If you want more "grip" with a soft compound, it's going to come at the expense of added heat (generally not a good thing) and/or wear. If you want better wear, you'll be trading off grip or heat. This is why if you go buying tires for your car, you can either get the high mileage warranty tires that aren't particularly sporty... or you can get a sporty summer tire without much tread life. You're stuck in a box and can't get it all.

What do you mean by heat?
Also that is very simplified model and does not really convey how tyres work.
Grip (i.e. elasticity) and wear (i.e. tensile strength) are bot functions of the current temperature, with elasticity increasing and tensile strength decreasing with rising temperature (at least in general).
So operating a tyre is a compromise, that is adjusted by the rubber mixture and the temperature.

Then the other dimension is cost and R&D. A company with a lot of resources at its disposal can expand the size of that box. That's the difference between a Bridgestone and a Pirelli, really. For Pirelli to come into F1 and try to have enough grip for the cars to get around (or be anywhere near Bridgestone) it comes at the expense of them disintegrating with terrible wear or durability margin. This is also why I hate the line of "Oh well FIA asked Pirelli to make junk tires to spice up the racing." Just isn't really the case. The experience and development box Pirelli have just does not match Bridgestone, Goodyear, or Michelin who are much larger companies with much more extensive experience. Not to say that Pirelli are idiots or anything, they just don't have the firepower the bigger companies have. Just like comparing Marussia F1 to Ferrari or Red Bull.

It doesn't matter how big the parent company is, Pirelli Disintegrating Tires Inc (whatever they're called) is currently quite active in racing, so money should not be the issue. To adapt your analogy to the teams, Mercedes is not automatically better than McLaren, just because they sell more road cars.

Tom ,I hear you ,but don´t you think taking a set of data derived from a rig is useless crap when the information you get is so far from reality that putting a fly on the rear wing gurney will throw all your data out of proportion?
In case your data produces realiable results in on track performance -that´s perfect...but looking at Formula 1 these days it does not look like the teams have any reliable data base to produce a working tyre model.

If it´s impossible to separate the tyre characteristic from noise in real world testing -i fear the tyre charecterisation is a pink elefant not worth chasing as you either hit or miss.So you just concentrate on optimising temperature rise and distribution and look after your pressures and that ´s about it instead of putting so many equations behind the tyre understanding and forget the cloud of uncertainty you are discribing with all this.
I often have the feeling with the sims I happen to have access to: hey i don´t need 100hrs of calculation time to know what will happen ...

I think the teams would be really helped, if they get a stack of tyres, can put them on a rolling road and test how the thing behaves at precise temperatures, loads, camber.... It's not really to get a simulation model but having some idea of how the rubber will react to setup or treatment changes should be valuable. They could replicate that on the track (they are allowed suspension load sensors, aren't they?) but that would take a while.

[Jersey Tom]

Tom ,I hear you ,but don´t you think taking a set of data derived from a rig is useless crap when the information you get is so far from reality

I don't find it to be far from reality though ("rig" tire testing in general that is). There's a reason why it's ubiquitous in industry - it works!

In some respect it's not unlike anything else... wind tunnels (if you want to call that an aero rig), engine dynos, damper dynos, K&C rig, whatever. If you have a good facility and know what you're doing as far as running a test plan, you can get very good and very useful data. If you can't get good data in a controlled environment, I think you're sunk trying to get it in a live environment (since fundamentally the hardware used to measure the system response is pretty similar in either case).

Then beyond that, as with any tool you need to have the experience to know what it's good for and what it isn't - the strengths and limitations.

[Jersey Tom]

What do you mean by heat?
Also that is very simplified model and does not really convey how tyres work.
Grip (i.e. elasticity) and wear (i.e. tensile strength) are bot functions of the current temperature, with elasticity increasing and tensile strength decreasing with rising temperature (at least in general).
So operating a tyre is a compromise, that is adjusted by the rubber mixture and the temperature.

Heat as in running temperature. In general, and certainly for the purposes of an internet forum, it's a pretty good visualization of the trade offs that a company like Pirelli has to consider when developing tires (be they race or consumer).

Heat generally being bad, if they want to bring a higher grip tread rubber it's going to come at the expense of running hotter (more hysteretic) and/or wearing faster (softer/weaker). If you want better longevity you're either going to have to sacrifice some grip or put more rubber on the thing (hotter). If heat is a concern you either have to take rubber out of the thing or take some grip out.

Or if you want to get better in an area without sacrificing elsewhere, you need R&D.

Because of that tradeoff triangle though I feel Pirelli is a bit stuck at the moment without much margin to bring better product until they have more years and R&D in the sport under their belt.

It doesn't matter how big the parent company is, Pirelli Disintegrating Tires Inc (whatever they're called) is currently quite active in racing, so money should not be the issue. To adapt your analogy to the teams, Mercedes is not automatically better than McLaren, just because they sell more road cars.

I just can't agree with this statement. The amount of experience and R&D you can leverage is a big part of how you get ahead in any field... and I don't see Pirelli being able to bring as much firepower to bear as any of the "Big 3" tire conglomerates (Goodyear / Dunlop, Bridgestone / Firestone, Michelin / BFG). That's admittedly a bit subjective on my part but I think bears out with Pirelli's previous ventures in F1 during open competition.

[Lycoming]

I believe pirelli can make a far more durable tyre than what they currently have, without large detriment to the other parameters. Hembery said that it would have been easier for them to produce a tyre that lasts the entire race distance. That said, I don't believe that they could make a tyre that was as good as the bridgestones in '10. At least, not yet. You cannot compete with the years of experience that Bridgestone had by then. I don't feel prepared to comment on how their resources compare though. Bridgestone may be a bigger company, but how much effort did each put into their F1 program? in any case, my argument about them having more experience still stands.

I think the teams would be really helped, if they get a stack of tyres, can put them on a rolling road and test how the thing behaves at precise temperatures, loads, camber.... It's not really to get a simulation model but having some idea of how the rubber will react to setup or treatment changes should be valuable. They could replicate that on the track (they are allowed suspension load sensors, aren't they?) but that would take a while.

If they had test data, certainly it would be useful. I don't think you can control temperature very precisely on test rigs, though you can control normal load and camber reasonably well.

[Jersey Tom]

I think the teams would be really helped, if they get a stack of tyres, can put them on a rolling road and test how the thing behaves at precise temperatures, loads, camber.... It's not really to get a simulation model but having some idea of how the rubber will react to setup or treatment changes should be valuable. They could replicate that on the track (they are allowed suspension load sensors, aren't they?) but that would take a while.

If they had test data, certainly it would be useful. I don't think you can control temperature very precisely on test rigs, though you can control normal load and camber reasonably well.

Who is to say Pirelli isn't already supplying this information? I'd say it's a fairly typical expectation for a tire company to supply this exact data. That said - and to my earlier point - getting it right is not trivial.

But without being directly involved who is to say what they get and what they don't, or what quality the data is. Whatever the data package is, still seems to be a struggle.

[marcush.]

Pirelli boasted around they are supplying "aero"test tyres to mimic the behaviour of the tyre for aero testing in the tunnel and they supply whatever data from their tyre onroad testing to the teams-Hembrey somewhere stating they run the test car with right everything in terms of sensors you possibly could think of relating to dynamic testing and much more elaborate than any of the teams would do ..
What i have not heard of is Pirelli supplying anything like rig testing data or conclusions they derived from it.The teams have no access to the tyres for rig testing .if I´m correct this is explicitely outlawed .
So the question is how to get that sort of information -when it is so important -and you are not allowed to actually perform that testing +your supplier is unwilling or unable to produce those numbers?