Tyre temperatures

[Tim Ling]

I get the feeling there may not be a precise answer to this, but here goes.

The setup guide recommends tyre temps of 90-110 deg. Should I put air in to increase the temp, or take it out? And how many....whatsits...equal 1psi?

I am trying to understand how setups work, lets just say I'm a little, um, special, and need extra help

 

[Luc Mangas]

Hm, I don't agree with this. As the tires "lean" while cornering your aim is to set the camber so that the tire contact patch is as big as possible. The general guide to get the contact right is to take a reading of the tire temperatures after doing at least 5 laps. The temperatures should be about 10c lower on the outer compared to the inner, the middle should be somewhere in between...

Hmmm. Aren't we saying the same thing ?
In my mind, something like (outer) 85 90 95 (inner) is ok, which seems to fit your description, and mine. No?

 

[Luc Mangas]

Seconded on this one Karl ... I have too found that much less than 10°c gives me better traction, and the default camber is often several clicks too negative for good race setup.

I haven't aired this view before as everyone else still seemed to be sure that ~10° is best.

I think I have also noticed this behaviour : with a friend of mine, we were doing comparative testing, and a front camber set to 2.6° was clearly better than the default 2.9°; WTCC , Seat Leon.

 

[Luc Mangas]

To jump back to my initial problem (very low temps on rear tyres), I did some testing:
-Initial conditions : Curitiba WTCC, Seat Leon, Dry.
-By increasing rear springs and increasing front sway bar, I was able to heat up my left rear tyre (78 82 85). I drove a bit "harder" than usual, and I could felt the car going slightly sliding in the corners.
-No matter what I do, my rear right tyre is somewhere around 65 62 60°
parameters tried : rear sway bar, spring, tyre pressure (very low and high values), slow bump/rebound and reduced camber.
The thing is the rear right tyre is only hard pressed on 2 turns, so that may explains why it's so low. But still.
I would like to know if someone is able to heat up this specific tyre, and how ? I am clueless here.

 

[Attila Domján]

I think you guys pay too much attention to this tyre temperature issue. Make it evenly increasing from outer to inner, at around max 10 C difference inbetween, and thats it, no other magic thing is behind to make them work better.

If you already achieved it, it is much more important to find the good balance of the car with ARB-s, then to spend hours to find how to get overall few degrees more heat to the tyres. First i think you will not really succeed in it, second, it does not matter to have 1-2 C higher overall temperature, even if by some magic you can do it.

On a track with only right hand corners mostly like Curitiba especially dont expect the right tyres to get up to the optimum heat, they will never do.

 

[Rok Prosen]

I completly agree with Attila. I wanted to post that myself but he beat me...


You have to setup youre tires to some degree but from there on there are more importent things to work on...

 

[Luc Mangas]

Ok, got your point
To give you the complete picture, I have a tendency to lock-up the rear wheels when braking hard, which is why I wanted to fix my temps first, to get more grip in the rear.
(I am already at 58-42 brake ratio, 95% brake pressure, wing 4).

 

[Attila Domján]

Already? try 60/40, thats still pretty normal.

If you are locking the brakes, make a hard braking, to make sure you really lock them, then look back your action in replay slowly from the side to see which wheels are locking first, and adjust the brake balance accordingly (naturally if rear ones are locking first move brake bias more to front) Make a few warm up lap before this.

Try to make it in horizontal straight, since the effect can change slightly on a hill or on a steep. (Monza is perfect for such test)

 

[Luc Mangas]

Well, my usual setup is 53 - 47, it brakes quite well, that's why I am concerned with a 60/40.
Oh, trust me, I know very well the replay feature And I can tell you I am always locking the inner rear wheel, I mean the rear right tyre... (you know, the one which is 65 62 60 ).

 

[Attila Domján]

Brake bias can vary from track to track what is good, depends on the braking zones. Usually i run with 58.5 on front, but for example Valencia 60/40 works better for me.

At least a try it worth, and if it will not help, then at least you know it is not helping.

 

[Michael Herrmann]

i found for my self on tracks with not so much hard brakingzones and fast corners a brakebalance from 58/42 is realy good on tracks where near every turne needs a hard braking i run more comfortable with 60/40
latley i try to move the balance while racing, have set it to my stickshifter, so i can adjust the balance acording the tracksection i am in

 

[Luc Mangas]

My current setup is 60/40 with a brake pressure of 90%. I am still locking up the rears in the 2 hard brakes, but I will stick with this one. Thank you all for your advices.

For now, my conclusion, as Attila said, is that sometimes you can't do nothing for the tyre temps, no matter what parameters you change. If the tyre is not really hard pressed, well, it won't heat up. So, no need to spend countless hours trying 50 billions setups .

 

[Lee Downham]

But that still doesn't mean you should ignore tyre temps, they tell you where your car has grip and where it doesn't, giving you indicators as to what may need changing in your setup in order to get even more grip
(ooooh don't you just hate that man playing the "devil's advocate" )

 

[Attila Domján]

loooool Lee

I know what you mean, i myself also a kind of perfecionalist, but please please please, if you have so much endless hours to fiddle with setup, and your tyre temps are already 10C diff and middle is inbetween, then try to look away from them, and make setup trials not in direction to improve tyre temps, but to reach the car behaving better in certain part of the tracks (car balance, accelerate out, gear ratio, and i could go on). Believe me, you will have much more success in improving your laptimes.

Please believe, i am trying to help with this advice.

 

[Rok Prosen]

If they lock at low speeds its completly normal... logicly

 

[Luc Mangas]

But that still doesn't mean you should ignore tyre temps, they tell you where your car has grip and where it doesn't, giving you indicators as to what may need changing in your setup in order to get even more grip
(ooooh don't you just hate that man playing the "devil's advocate" )

Yeah, yeah yeah, Devil's advocate for sure ! You are teasing me all the time

 

[Luc Mangas]

If they lock at low speeds its completly normal... logicly

In at least one of the turn (4th corner, hard left), I brake, I lock. simple as that.

 

[Luc Mangas]

loooool Lee

I know what you mean, i myself also a kind of perfecionalist, but please please please, if you have so much endless hours to fiddle with setup, and your tyre temps are already 10C diff and middle is inbetween, then try to look away from them, and make setup trials not in direction to improve tyre temps, but to reach the car behaving better in certain part of the tracks (car balance, accelerate out, gear ratio, and i could go on). Believe me, you will have much more success in improving your laptimes.

Please believe, i am trying to help with this advice.

I am trying to cut on the "endless hours with setup" :sigarette:.
It's much more difficult to feel the car balance & stability, then reading temps, that's why I adopted this approach at first.
Anyway, agree with both of you, feeling the car is the way to go.

 

[Rok Prosen]

Then give youre setup to someone else and let him try what happens on the track (on the same track with the same car).
Maybe youll find solution faster this way... worth a try

Wish you all the best with your setup...

 

[Lee Downham]

Also try reducing the amount of pressure with the brakes if you find you lock up everywhere - each track and setup brings with it different tendencies. If you find your wheels locking up each time you touch the brake, reduce the pressure a few clicks until you find a good balance (ooooh there he goes again with that balance thing) ...
Remember a skidding car stops more slowly than a rolling one

EDIT: somtimes I will spend a lot of time with specific track / car setup - but I do it in the interest of self-education ... ie learning to understand and how to fix a specific issue. Once I have done this though, next time I encounter the issue, I find I can quickly resolve it. Its a slow process sometimes, but I love being able to tune the settings to make a car drive how I want it to now, rather than the "hit and hope" clicking I did in the past.

 

[Luc Mangas]

rather than the "hit and hope" clicking I did in the past.

I like this quote, "hit and hope".
Same here for the learning thing, I think I did some progress on this side, especially in the braking process. Now I have to figure the slow / fast bump / rebound :clap: