Unrealistic tyre model?

[Steven]

Is it just me or does the tyre model physics seem to be unrealistically accelerated?

By that i mean tyre temps will heat up and cool far down far too quickly, for example in the formula renault cars tyre temps on straights, even after 3 laps will drop to ~ 35 degrees and can build up well over 100 in corners.

Furthermore flat spots seem to clean themselves up within a matter of meters rather than half a lap or so.

I would be interested to know if this is a bug or intentional. My appologies if this has been covered elsewhere.

[Goffik]

There is a document in the root folder called KnownIssues.txt. It's worth a quick read. Doesn't necessarily answer specifics, but it can point you towards an answer.

Tire Model
==========
-Contact patch load distribution model is not final, which means tire pressure does not have the full effect that it should.
-Aquaplaning is not implemented, so wet weather driving is only properly modelled when the track is damp but with no standing water.
-Wear (meaning both abrasion and degradation) is incomplete in several aspects.
-There are other relatively minor loose ends.
-Curbs, white lines have almost no grip in rain

[Steven]

There is a document in the root folder called KnownIssues.txt. It's worth a quick read. Doesn't necessarily answer specifics, but it can point you towards an answer.

Thanks for that, not sure if those known issues cover what I am describing though. Might need someone from isi just to confirm. Atm the FR car is awfull to drive, low grip and predictability

[Taxi645]

I must admit that I've seen very wild tire temp readings on the megane. Further more the temp difference between inside and outside of the tire is very large as well even at more moderate camber setting. Much more varying than with rF1, that's for sure. That said I obviously understand it's beta so see it as feedback rather as negative criticism.

[mianiak]

That's because the temperature is taken from the surface of the tire tread, deep within the tire it is still cold, you will notice that it will also cool down very quickly as the heat from the surface of the tread disperses into the tire. Then once you have done a few laps, the temperature within the whole thickness of the tread area begins to heat up.

[samuelkorthof]

I think u wil have to let rF1 go. As good as it was as a simracer you canŽt use it as reference. Wild changes in tiretemp can be a issue in reallife. It al depends on how you drive and what setup ur using. On reallife track IŽve seen guys wasting their tires in just 2 laps while others could run 10 or more. Racing rF2 is very different than rF1 and you will have too rethink about your driving. IŽam not very bad at racing but when I just did some laps after installing rF2 I looked like a total noob. Also the not finished tiremodel can be part of the problem although I think it has a very strong basis.

[Steven]

That's because the temperature is taken from the surface of the tire tread, deep within the tire it is still cold, you will notice that it will also cool down very quickly as the heat from the surface of the tread disperses into the tire. Then once you have done a few laps, the temperature within the whole thickness of the tread area begins to heat up.

How many laps would you suggest it should take to warm the entire tyre? Because after 5 laps around sepang (a highly demanding circuit on tyres) my temperatures across the line were still only 42 - 35C. Far lower than what I would expect from a racing slick with a track temperature of 29C

I am pretty confident this is incorrect and may be partially why the Formula Renault car can be so loose as the temp range for a racing slick is usually well above at least 80C

You can see in this video (not mine) some of what I am talking about:

[samuelkorthof]

That doesnŽt seem too look good indeed. What is the amount tirepressure?

[jubuttib]

Yep, the big fluctuations are due to the surface getting hot faster than the core, but it's also true that at the moment the tyres don't seem to heat up at all if there isn't some slip (turning the wheel too much, locking brakes, spinning the rears, sliding sideways), temps can actually get lower if you limit steering input and full throttle isn't enough to break grip. Load doesn't seem to affect it at all, neither does normal rolling resistance, so it's hard to get the tyres to warm up no matter how many laps you drive.

It's definitely a bug, not an inherent quality of the tyre model.

[Terence Groening]

I can confirm that right now the temperature reading is from the surface as if you were reading with an infrared temperature sensor; at some point we'll provide more detailed info of the internal temperatures (like any good tire engineer would retrieve with a probe).

Some of the other things mentioned here will also be improved in the near future.

[ajk]

I reckon the temps are surface readings but FR 3.5 bottom end temps do not build up even over time. They cool so fast, faster than brakes. The brakes should also warm the rim, the tyre and the air inside. My beliefs on tyre temp build-up are probably non-sense but I dare to plea in common sense and practical every-day observations on hot objects cooling over time. Tyres cool off very rapidly (not as rapidly though) even if stationary.

I hope there's a scientific explanation behind all this. Because it's too obvious of a flaw (if it is) and makes me wonder how such a bug have remained in first release candidate without anyone noticing or even worse if it's a known issue of "incomplete" tyre model then whole model is either total bogus or early alpha state.

If it's a bug in FR 3.5 I still wonder how it was released as it is but I dare to doubt that too because Megane and historics also tend to cool quickly (not as quickly though).

Given open beta was mainly aimed at testing developer tools and ISI saying they could have released a very unfinished version a year ago already I honestly expected the physics core to be solid and 99% ready.

EDIT: written in notepad before TG's response

[Dimahoo]

Well you could prehaps have 5x5 groups of dots in the tyre read out.
We can already see the numbers representing the surface tyre temps as they're listed.
What about a 5 x 5 grid showing you a 3 internal temp read outs, with each temp represented as a colour like...

c = blue
w = red
h = Red

ccccc
cwwwc
cwhwc
cwwwc
ccccc

Changing accordingly in game as they heat and cool.

Theres a separate telementary screen for outside surface temps on Outer, middle and inner tyre temps isn't there?
(so you gauge camber adjustments)

[Steven]

I can confirm that right now the temperature reading is from the surface as if you were reading with an infrared temperature sensor; at some point we'll provide more detailed info of the internal temperatures (like any good tire engineer would retrieve with a probe).

Some of the other things mentioned here will also be improved in the near future.

Thanks for the response I very much understand that this is still beta and can be worked on, hopefully it isnt a fundamental problem with the tyre model/physics.

Would you be able to confirm how much impact these tire issues are having on the physics of the cars as a whole? For example could this explain some of the difficulties some seem to be having with the formula renaults or are the cars handling exactly as intended? Your input is greatly appreciated.

[Tim Wheatley]

Can't answer the technical questions (Terence wrote the tire model), but from my experience in testing I've had it take at least 5-7 laps of Sepang for the tires to feel appropriate levels of grip. And these laps usually had to be good, stable laps, not abusing the tire.

[RCRacing]

It seems folks are expecting this to act like the final product. WE ARE BETA TESTERS for 6 mos. Thats what we have signed up for. Continue testing.

[deBorgo83]

Just had a run at Mills to try out a weather cycle, had the game go from light cloud through a heavy storm and back to partial cloud in 15 mins. I was on the track the whole time but pitted for rain tyres when the storm came. By the end of the session a dry line had emerged on the track but even then the rain tyres still didn't retain any heat. Even accepting what we now know, that the tyre temp readings we get are surface temps, I'd have expected rain tyres to be getting very hot in such conditions.
Loved the weather cycle btw, in general I'm really enjoying the beta so far.

[Steven]

Can't answer the technical questions (Terence wrote the tire model), but from my experience in testing I've had it take at least 5-7 laps of Sepang for the tires to feel appropriate levels of grip. And these laps usually had to be good, stable laps, not abusing the tire.

That's fair enough, having to treat your tires correctly in rF2 was one of the main reasons I purchased. I just cant help thinking that if my tires were 40C hotter entering a corner there would be a significant impact on handling.

It seems folks are expecting this to act like the final product. WE ARE BETA TESTERS for 6 mos. Thats what we have signed up for. Continue testing.

Yes and as I said above I understand that this isn't the finished product but as testers we should provide feedback. I don't think anyone was being negative towards ISI or the product, I personally just wanted to know if the behavior was intentional.