F1technical.net

mep wrote:Why they can't simply crap one of these tires mount them on a tire test rig and measure out all the data’s they need.

If only it were that straight forward.

I read that apparently the W01 hot exhaust gas around the diffuser was causing some of the deficiencies. Making tyre readings near impossible...

JohnsonsEvilTwin wrote:I read that apparently the W01 hot exhaust gas around the diffuser was causing some of the deficiencies. Making tyre readings near impossible...

Hmm, if this is true, it points to the rear end of the WO1 being too cluttered to allow the smooth air flow needed to take the heat away.

autogyro wrote:

JohnsonsEvilTwin wrote:I read that apparently the W01 hot exhaust gas around the diffuser was causing some of the deficiencies. Making tyre readings near impossible...

Hmm, if this is true, it points to the rear end of the WO1 being too cluttered to allow the smooth air flow needed to take the heat away.

This was the first race weekend Mercedes used the (low)exhaust driven diffuser.
I think it has more to with them not having tested it correctly rather than anything exceptionally wrong with the rear end.

Good point JET but Merc seem to be continualy in this problem situation .

Here is an interesting view: http://www.autosport.com/news/report.php/id/85074.

Trulli, for one, believes that moving the c.g. of his Lotus forward will help performance. The next few days might be a good test of the theory (though I am sure he would also like a quantum leap in aero....)

Thanks DaveW

naturally the CoG shift will have an effect on the tyres. But how do teams test for this?

Look at tire data (if you have it, and it doesn't suck). Run it in a sim (if you have it, and it doesn't suck). Change your car setup / ballast, and drive it.

Jersey Tom wrote:

mep wrote:Why they can't simply crap one of these tires mount them on a tire test rig and measure out all the data’s they need.

If only it were that straight forward.

Why not?
Be a bit more precise.
You said a similar thing here:

Look at tire data (if you have it, and it doesn't suck). Run it in a sim (if you have it, and it doesn't suck). Change your car setup / ballast, and drive it.

So basically this all hinges on a tyre simulator?
I knew they were important, but this adds even more importance to it.

Someone on this very site did allude to CFD and modeling software as "its only as good as the numbers being put in and taken out of it".
Mercedes numbers dont appear to be adding up in general.

As I mentioned earlier, Valencia was a bit of a calamity for MErcedes becuase of the rushed exhaust not being good for taking accurate measurements for the tyres. Lets hope they fix this for Silverstone.

Mep- it's hard to explain without being able to show real tire test data.

Suffice to say... pretty often it's real hard to make conclusive sense of, even if you have heaps of test data.

Very frustrating.

JohnsonsEvilTwin wrote:...

Someone on this very site did allude to CFD and modeling software as "its only as good as the numbers being put in and taken out of it".

...

Well, it's not only the numbers being put in. When you do a model, you assume that the world is static. I mean, you assume that all wheels are the same.

In racing, that's not true. Even in karts, the change in grip and temperature characteristics between a set of tyres and a different one are abysmal. That's precisely the key to (and the purpose of) tuning a race car: to understand every set of tyres you're going to use.

In NASCAR is even more pathetic: imagine the number of tyres they use. Multiply for the number of cars. Imagine now the inhomogeneities (that is, the variability from one set to another).

So, the problem here is the size of the standard deviation of parameters... as always.

As they say down here: "when I learned all the answers, they changed all the questions".

It's the same here: you run a long set of tests, find all the numbers there is in this world about a tyre. Then you go to the track and the racing tyres you use behave differently. Aint life a b..ch?

officially the tyre evaluation is not allowed if it is not a test performed on the car in official sessions...
so how can you legally aquire reliable data to put in your sim? you only get snapshots from wha you can gather in testing and practise sessions and try to adapt your sim to what th ereal thing does?

marcush. wrote:officially the tyre evaluation is not allowed if it is not a test performed on the car in official sessions...
so how can you legally aquire reliable data to put in your sim? you only get snapshots from wha you can gather in testing and practise sessions and try to adapt your sim to what th ereal thing does?

Allowed or not, to many things in our world are not allowed. If you stick to all these rules you would never achieve anything.

Of course the first thing you do is to ask kindly the tire supplier to give you all the data’s. When they deny you simply crap the tires and test it yourself. Too many things are related to the tires to just guess around there.
As I told on previous post you simply build a test rig in one of your trucks and during a GP weekend you will get all the information you need.

Ciro Pabón wrote: Well, it's not only the numbers being put in. When you do a model, you assume that the world is static. I mean, you assume that all wheels are the same.

In racing, that's not true. Even in karts, the change in grip and temperature characteristics between a set of tyres and a different one are abysmal. That's precisely the key to (and the purpose of) tuning a race car: to understand every set of tyres you're going to use.

In NASCAR is even more pathetic: imagine the number of tyres they use. Multiply for the number of cars. Imagine now the inhomogeneities (that is, the variability from one set to another).

So, the problem here is the size of the standard deviation of parameters... as always.

As they say down here: "when I learned all the answers, they changed all the questions".

It's the same here: you run a long set of tests, find all the numbers there is in this world about a tyre. Then you go to the track and the racing tyres you use behave differently. Aint life a b..ch?

Absolutely agree with that.
There is as of yet no substitute for real world testing. From what you are saying about the inhomogeneities of tyres from somthing as basic as a Go Kart, the variables would naturally be more sensitive as you go up the ladder.

What I'm getting from your post is that its not just the car that uses its tyres best. But the car that can use its tyres effectivley in a number of conditions(an all rounder) which makes sense.
Somtimes I wonder if the people that make their tyres work best sometimes do it unwittingly?