>>>>So how I can increase the speed of temperature rise ? And keep the optimal pressure at 1.9 and 2.0bars after 3 laps.
Typical RF2 tyres are very slow to stabilize pressures, you can drive for 7 or 10 laps until they reach maximum. Why? I don't know exactly. It's a result of many things. Is this realistic? I don't think so.
The good new is that we still can change some thermodynamic properties to obtain something closer to the real thing.
Normally, the tyres are accumulating heat slower because the overall "specific heat" is too high. Specific heat is like the inertia for temperature speed. That means the tyre accumulates heat slowly, due to damping heat energy introducing energy constantly and also cornering friction, of course. Internal conductivities are probably also slow and external refrigeration is not enough. Try setting a faster conductivity and lower specific heat rates for materials at each node.
Those parameters can be changed without regeneration of the tyre.
After that, depending on result, you can rebalance the model using the rest of thermodynamic parameters.
Apart from those that Mantasisg said, don't forget this one, it can help a lot:
DryTerrainEffect=( , , x) /// multiplier for cornering friction heating rate
Also, conductivity and specific heat rates can be set for different temperatures. This means that you might be interested in applying a low specific heat when the tyre is cold (so that it heats up fast) and a high specific heat rate when the tyre is hot (so that it doesn't heat up so easily when it is already hot)
TreadMaterial=(273.15, , , , , 850, 0.251) /// for 0ºC
TreadMaterial=(373.15, , , , , 6750, 0.241) /// for 100ºC
The goal is not to use realistic specific heat numbers, of course, this is not important at all, don't mind using unrealistic values ten millions bigger than realistic. The priority is achieving a realistic result.
Realistic values that provide unrealistic results are useless. Perhaps we are allowed to use unrealistic values which lead to realistic results, instead.
Remember that temperature behavior will also change handling, because tyre flexibility and grip properties also change fast depending on temperature ups and downs.
Apart from that, the optimum pressure issue. This is very difficult to fix on RF2. Optimum pressures for grip are usually very low on RF2, probably because the model benefits too much the amount of contact patch surface, without having in account the issues that a low inflation induces. However, i don't know. The only thing sure it that optimum pressures are wrong, and that creates a chain of flaws (especially when we add them to other issues).
For example, most of sim racers will use the minimum tyre pressures available if they want to be fast. No problem with roll resistance or tyre temperature, RF2 will not create enough of them at any pressure, no matter how low is it, but you will earn a lot of grip.
The grip gain is so big that most of times it is not good to push the tyres to optimum temperatures, especially at endurance stints. Because if you push the tyres you will increase tyre temperature, and that is good if you are still under optimum tyre temperature, but that will also increase tyre pressure, and that is always bad. The more tyre pressure the more grip you lose, then it is better to keep tyres under their theorical optimum temperature. As a weird result we obtain that tyres are faster at temperatures below their true optimum temperatures.
For example, if the theorical optimum temperature of a certain tyre is 100ºC, the 'true' optimum tyre temperature is 90ºC, because at 100ºC the higher pressure makes you lose a lot of grip..... and I don't think that's realistic.
Well, i hope some day there is a revision or fix for those flaws...
