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

 

[Sebastien Levret]

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

Can you tell me where can I found this Setup guide ? Is it a Setup guide written by a member of this community ?

 

[Luc Mangas]

http://forum.racedepartment.com/gtr-evolution/3511-rd-setup-guide-gtr-evolution-race-07-a.html

 

[Sebastien Levret]

Ok thank you, i will read this setup guide this evening after my working day.

 

[Lee Downham]

Ok, so who wants to be my race engineer?

I'm in the FBMW, at Spa04, and I can't get the tyre temps up.

Because the track is SO bumpy, if I put spring rates up the car turns into a Tokyo Drifter. This is the highest I can get it, should I just accept that my temps will be lower around spa?

I have the same issue as Hexman with the Seat Leon (WTCC), my rear tyres are always in the 75° vicinity. I tried lots of settings (anti roll bar, low pressure, high pressure), nothing helped to heat them up to 90°.
Lee Downham, if you stiffen the spring, you will loose grip, no ? what's the point of heating up to 90 if in the end, you have less grip ? I mean, the final objective is to get the maximum grip

:rotfl: ... LOL ... :rotfl:

Sorry to laugh but its proper black magic all this setup lark eh?
I am no expert, I too am learning with you all ... :glasses-nerdy:

The stuff I have quoted is what I have read and/or have tried and has worked for me in the past ... but I have found some tracks and cars just seem to go against everything that is "the norm" ... never tried a WTCC Seat at Spa, so can't tell you from personal experience what has worked there.

What I have been doing a lot more lately is along the lines of what Atti suggested ... (thanks for the handy hint there dude :wink2 ... so lowering the spring/arb/etc right down and starting from there ... but I always tend to leave tyre pressures at or around 180kPa until I have got the base settings for suspension etc more sorted and the car is driving how I like it.

Something which may or may not help is playing with the ride height.
I believe I am right in saying that if you lower the ride height you compress the springs, thus effectively increasing the amount of pressure on them without actually touching the spring rate settings.

One thing I would suggest is that there is something else more fundamentally wrong with the settings you have Jamie, as your tyre pressures are WAAYYY lower than I would expect for the WTCC's ... although I may be wrong here as I really have done very little with WTCC's for some reason (been doing GT and mini stuff since starting my setup education I guess), I would normally expect to have them up near 180kPa.

One thing I sometimes do if I am struggling is experiment wildly to see if I can find something that is going to point me in the right direction ...
Put springs and ARB to minimum, then drive and see what happens.
Whack the spring rate to max ... drive.
Mess with ride height and spring rate combinations, etc
Dampers can help with over/understeer alot, but try to wait until you have the "harder" settings like springs etc sorted.

Always make sure you do 4 or 5 laps before you decide something is good or bad ... tyres need to get to and settle with their working temps before you can truly assess what is going on with the car.

Hope this mad set of ramblings helps chaps ... there is science in this I believe, and I am starting to understand it all a bit more, but sometimes there is soooo much frustration and confusion ... a good setup takes a long time and a lot of work in my experience, and this is why they are (rightfully :wink2 "protected" here behind closed doors at RD.

BTW: Make sure you thank anyone who posts up a setup no matter how good or bad it is, try to give them constructive feedback too, I wish more people did with mine (eg. too oversteery at corner entry / exit, gearing wrong, snappy, feels like a pogo stick, beautiful I took 5 seconds off my pb ...etc) ... give you more incentive to keep trying and keep posting.

 

[Istvan Schmidt]

What do I do when the front tyres don't warm enough? The rear tyres are 80-96 degree, but the front tyres don't 75 or above.

 

[Attila Domján]

The absolute temperature you cant do too much about, you can just make suspension adjustment to modify the heat over the surface of the tyre, aim for 10 C diff between inner and outer, you can adjust it with Camber, and with tyre pressure adjust that middle of the tyre is right inbetween also in temp.

 

[Lee Downham]

Hmmm ... not wanting to be argumentative Atti, cos I respect your input and advice greatly, but not sure I totally agree with the "absolute temperature" thing - things like increasing spring rates pushes the tyre harder into the tarmac, creating more friction and so generating more heat. Too much can lose you grip tho (soften might actually increase heat, as there will be more grip and friction) ... as with all of this its a fine balance
If the setup is badly wrong in other places, I find you will get no grip and the tyre temps will fall like a stone, or conversely tyres may overheat with a poor setup or loss of grip.
There are obviously limits to how much you can affect the tyre temps, but a good setup will see more even temps across all four tyres, having hot rears and cold fronts to me indicates there is something not quite right with the setup and more work is required

(again ... me = no guru ... these are just my mad ramblings and 2 cents worth)

 

[Alan Chan]

I had my own tyre temp. experience
when i setup Formula BMW in Brands Hatch Indy
my left front tyre in very hot (i tried 6 lap 3 parts of tyre are over 100Degrees C)
i tried to reduce camber degree or increase tyre pressure
but it still keep in high temp
how to solve it ??

 

[Tim Ling]

I think you're supposed to lower the ARB to try and even the temps across the front tyres. Maybe softening the suspension on the wheel might help, but I dont know how that would affect the setup for the rest of the car

 

[Lee Downham]

... true balancing act, and I personally find this is the hardest one to solve.

If you figure it out, let us know eh? :wink2:

 

[Alan Chan]

here is my rookie setup follow the rule from RD SETUP GUIDE
only camber tyre pressure & Differential i had set

i ran 6 laps continually :dance2:
u may see that left front tyre is much hotter than right front tyre

 

[Attila Domján]

Hi, i would increase Camber, and decrease front left tyre pressure.

Lee, surely you can play with it, but the effect of other suspension settings you will find not too much difference on the tyre temp itself, but the behaviour of the car, so loook for that with those settings, and dont adjust them to make tyre temp better.

 

[Luc Mangas]

here is my rookie setup follow the rule from RD SETUP GUIDE

>> Too much pressure on the front left tyre, you can see it with the 3 temps : the middle one (107) is higher than the 2 others.
Try to aim for (outer) 87 90 93 (inner)

 

[Alan Chan]

tyre temp in middle should lower than outer or inner ?

 

[Luc Mangas]

The inner temp should be the max, and then progressively lower for the 2 others. If possible, less than 10° between inner and outer (can be adjusted with camber).

 

[Sebastien Levret]

A question about the camber, what is the advantage to have a camber of -2.9 deg or -3.5 deg ? Why don't put a camber of 0 deg, this will provide the same tyre temperature for the outer, the center and the inner of the tyre ?

 

[Luc Mangas]

camber helps quite well to turn, try 0 and you will see... On the other hand, if you put too much camber, only a part of the tyre will be in contact with the road, so less grip in the end; you can notice this effect when the outer temp is much lower (<18 -20 °) than the 2 others.

 

[Karl Westman]

The inner temp should be the max, and then progressively lower for the 2 others. If possible, less than 10° between inner and outer (can be adjusted with camber).

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...

If the middle temperature is lower than the inner and outer, your tire is under inflated. This may cause lack of grip and overheating.

If the middle temperature is higher than the inner and outer, your tire is over inflated. This may cause lack of grip.

Since Simbin has reprogrammed the tire modeling in GTR-EVO I've found that a temp spread of about 5c works better than 10c, but that might be due to my driving style... your mileage may vary...
:good:
Kind regards,
Karl

 

[Sebastien Levret]

I have the same problem with the tyre temperature of the seat. In every race the front left tyre is often over 100°C.
For example, for Curitiba race, I have this kind of setup (see the attached picture).

What is wrong with this configuration ?

Thank you

 

[Lee Downham]

Since Simbin has reprogrammed the tire modeling in GTR-EVO I've found that a temp spread of about 5c works better than 10c, but that might be due to my driving style... your mileage may vary...

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.