Tyre wear v/s Tyre graining

[Rideway]

Thanks a lot for your answer Marcush

Pick up is a fact of life..and at the end of the race -in lap -you will not push so the tyre will not be able to get rid of the pick up- i´d say.The inside is cleaner ,right? I fail to see if the inside of the tyre shows very slight pickup or it is the surface of the tyre that is ripped..maybe you give feedback if the small things can be peeled off.

I havent tried to peel it when they were warm. I will try it if it happens again in the next race...

the first tyre maybe is cold but shows quite a bit of deep routing and to me its a tyre that has seen it all and has seen -too much sliding-
but surely it would help to know what the tyres did (how many laps,heat cycles etc),if it´s front or rear

So maybe you ask your driver to try and be a bit more relaxed and not try harder when he feels the tyre is giving up on him. Reduce sliding the car ...if it´s not simply a out of balance issue... key is having the fronts and rears in the same temperature while having a good balance .

They were used in qualifying in two stints, circa 4 rounds each. Im quite certain those are front tyres. I fully agree with that, the drive might be too agressive with cold tires, therefore the grain. The driver complained about overall lack of grip and thats why I wanted to make sure with you that tyres were grained.

The second picture could also hint a little bit at a excessive toe issue more than a camber thing? But then your wear rate seems very low -when after the race the threaddept is still this much .....not enough info really yet.

i dont understand why a toe (in/out?) problem. could you please explain that? To be honest i think that those are rear tyres that do last much longer (front wheel driven car).

Thanks a lot!!

[malcolm]

Another tip:

Get your driver to keep driving quickly on the cool-down lap (or come in mid-session during practice), and take tire temps. That way you can see if you have too much camber or not. Also, if he comes in quickly, then you won't have that tire build-up obscuring the conditions of the tire.

Just a quick and simple test. If the insides of the tire are more than about 6 deg C hotter than the outside, then you have too much camber. 4-6 deg C difference is roughly optimum. Of course, you'll have to test a bit to see what works best for your car and tire combo.

[marcush.]

you will always have to compromise .A FWD racecar will wear out the rears at a lower rate usually and you have to be a bit creative to compensate .
some go for excessive cambers at the rear ,reducing effective contact patch .another possibility would be to use only used/worn tyres at the rear .

The question is what you really need :
You need a constant quick racecar from start to finish .It´s nice to have a lot of grip potential at the rear but as the grip increases at the rear the potential to go slower is very big as you will inevitably have understeer.
A tyre that has lost it´s edge a bit already will not peak as much as a new tyre .. and this should suit the situation at the front ....Your race will start with a tad of oversteer and as the fronts breath out their life the car will slowly transform into neutral steer ..

You could as well start with higher pressure at the rear to kill some grip.But honestly speaking it will worsen as the tyre sees some work...This can work .As always you need to know what your driver and car needs and work out a plan how to achieve the optimum.
To look at cambers ,toe or whatever is important no question ..but How can I know which setting will give you the grip you need to achieve a constant balance?

[speedsense]

First let me thank you a lot for your response!

What slight problem do you mean? Car balance? Brake problem? Grip? I fully agree with the excessive amount of camber, I've told them but as it was my first race, they didnt follow my advice.... But is good that you recognize those waves as graining as well.

What I mean is that in the data you see, did these tires come from the fronts of slightly understeering car or the rears of a slightly oversteering car. The graining isn't excessive, only slightly so.
As a fellow, though seasoned (over 400 races) data consultant, I can offer a bit of advice, it is best to only relate what you see in the data and leave the decisions/recommendations on car setup/driving to those who have much more experience than you do. It's best to listen for a few years, without interjecting your own ideas (If your job is only data). Even if you think you're totally correct and have proof, it is best to answer with what the data says, question/bring up the findings with your engineer or driver and let them decide.
As your new to this and this was your first race, putting in your own ideas to people around you that have many more years experience than you, can and mostly likely will lead to you being replaced. It's best to remain silent, learn, observe and ask questions on what you see and understand and learn as much as possible about the different techniques of analysis, rather than opening your mouth and removing all doubt on what you don't know.
I've seen many data guys last less than a year, telling experienced drivers how to drive and experienced crew chiefs/engineers how to engineer. After twenty years, I still don't do this, but rather lead the horses to water and make them drink, of their own free will, with the best tool in racing, data analysis.
Data Analysis is a long road and a rewarding one but using the analysis correctly also means doing so without stepping on toes. Doing the opposite is what stops most from ever being successful at it. IMHO

Again the camber excess, right. But those tiny bits on the left: do you think is also pickup? They look too tiny to me but you might be right.

Thank you very much once again

PS: just bought Paul´s book, lets see it if helps me a bit i will let you know

A cambered tire will often grain the inside edge, as it gains excess heat (compared to the rest of the tire) even on straightaways. Also, as was mentioned here can be a result of toe (fronts or rears..if they are adjustable in toe).
Haney's book will be useful to you, though it is a collection of ideas from assorted people in the business, while very good teaching tool, Haney isn't exactly an expert on tires, but rather used the expertise of others to write the book. Good book though.

[Jersey Tom]

I'd be very wary of anything tire-related you read in Paul's book.

Also I wouldn't necessarily say those tires are over-cambered or over-toe'd.

The cold set are overworked a bit, sure... but that's only lightly grained.