In real life the rubber on the racing line becomes very slippery, and drivers must look for grip offline. Picking up marbles on slick tires helps to channel the water. On a related note, drivers turn down their TC in the rain, because the increased wheel-spin also helps to channel water. Will these behaviors be modeled in AMS 2?
While its true that rain on a rubbered in racing line is initially slippy, it is also true that rain washes the rubber away. The Madness engine does model rubber on the racing line becoming slippery, though whether it does it enough is open to discussion. Indeed, the extent to which modern racing leads to a "rubbered" line is open to discussion - the days of the traditional dark racing line seem to be over. It also models the rubber getting washed away. What it probably doesn't model (and I don't think any sim does) is the difference in surface texture of tarmac on the racing line and off it. Tarmac on the racing line tends to get polished over time compared to that off the racing line. This makes it more slippy in the wet. With new tarmac there will be no difference on and off the racing line, and with old well-worn tarmac the difference will be noticeable. PC2 doesn't model the effect of marbles on the wet grip of slick tyres. I don't think anyone knew that this was a "thing" until Aris talked about it, and I don't think he knew it was a "thing" prior to working on ACC. I must admit I'm still somewhat skeptical about it as I've never heard F1 drivers or prototype drivers talk about it. I wonder how well marbles will stick when the tyre is cold and wet and the effect will presumably vary with how many marbles you manage to pick up. And presumably drivers will have to drive off-line to pick up the marbles, so how do they tell the difference between extra grip from marbles vs extra grip from driving off-line. I wonder where you can measure data on picking up marbles in the wet and where you will get data on the wet grip of a tyre with a known quantitly of marbles stuck to it. Finally if slick tyres can pick up marbles in the wet then presumably wet treaded tyres can too . But if they do its hard to imagine that a coating of marbles will actually help the grip of a treaded tyre. So you might think drivers would avoid going off the racing line in the wet with treaded tyres because it would adversely affect their grip. But in reality treaded tyres are driven off line either for the extra grip or to cool them down in drying conditions.
Funnily enough Aris posted on this topic today Also, if you accumulate marbles on the slick tyres, your slicks will manage to drain rain just a tiny bit better than being completely... well slicks. That's something real drivers also do when they want to risk to stay out on a wet track on slicks for some more laps. Again the effect is very very subtle. Assetto Corsa Competizione - 2019 Generic discussion So hats off to Kunos for including this but perhaps it doesn't render other sims obsolete.
