and make a box so if you have drift tires you can chose smoke color and make them smoke i can do a drift at 70 and the tires wont smoke as much as my real car dose at 40 mph
yes yes yes yes yeeeeessssssss thats all they need to do
Exactly. And in fact from test data I've seen this is exactly what happens. Both the overall grip and cornering stiffness increase as the tread wears down. This is why racers running non-slicks shave their tires, or buy pre-shaved ones to start with.
Slicks made out of some racing compounds are different though of course as they can start losing grip after just a couple of laps, perhaps due to crosslinks breaking and reattaching in unfavorable ways (I've seen some mention of this in literature). I.e., at the microscopic level the molecular contact changes. This loss of grip can be due to that and a few other different things that I won't get into here (and don't understand much myself), and even tire engineers don't fully understand it all. Friction is a sort of bizarre thing None of that needs to be directly modelled though, really. Just some man made curves will continue to suffice.
Yes, that's true. The cure of the tire is changing over time. What happens with really old tires is that they get harder and harder essentially since the cure is continuing to progress with every heat cycle, and at some point reversion can occur which basically means they sort of begin "uncuring" in a way and become getting softer. They are continuing to cure of course, but some of the properties can start reverting towards an uncured state.
I'm not sure if reversion really happens on street tires in practice though. By the time you get to that point you might have worn the tire right down to the cords. Beats me. But yes, this all changes throughout the life of a tire. Eventually old tires will probably start to lose grip as they become harder, but I haven't seen data on that so am not sure. But if you wear treaded tires down rather quickly as in racing, well, this may not happen quickly enough to actually cause a decrease in grip.
Actually, new tires can typically have 10-15% less grip than ones that have been broken in for a couple of hundred miles. From there on out as the tread wears down the grip generally continues to increase, although more slowly than in that first couple of hundred miles. (Racers also buy "pre-broken in" tires so they don't need to run them for awhile to get the grip up to normal. Pay a fee and they'll run them in on a machine for you). However, new tires might indeed feel better because the cornering stiffness is a lot lower. The tires are more floppy and forgiving (the peaks come in at higher slip angles). Feel and ultimate grip can be two different things.
It depends on what kind of rubber you're dealing with. Some rubbers (especially high grip, fast wearing rubbers found in racing) have grip characteristics that are remarkably sensitive to temperature. Other rubbers such as natural rubber and styrene-butadiene (SBR), commonly found in street tires, have virtually no temperature sensitivity until they get wickedly hot or cold, especially once you start throwing carbon black and other chemicals into the mix. This is why street tires just aren't really sensitive to temperature and you can abuse and drift them until you get to the cords before noticing any loss in grip, but grip in F-1 tires and most racing compounds is indeed very sensitive to temperature and wear in comparison. Grip is not really solely a function of temperature directly (there really isn't an "optimum temperature") but it's still a very good approximation and is certainly good enough for most sim drivers
I agree that it would be good to go ahead and have server options for what tires can be used, but I woudn't label the new compound as "drift tires," but use another term. It's the same thing, I'd just different choose language for it
I was reading an article by a race engineer talking about an up-coming F1 race and what kind of wear they expect to see. This was probably 3-4 years back and I was just starting to get into the whole racing thing and not much sank in. I know they discussed graining and blistering and another type of wear. As I understand it, those types of wear don't simply decrease the amount of rubber on there but have irreversible effects. Maybe Todd can tell us a bit more about that?
I'd also like to know how realistic is it that tyres tend to run cooler as they wear - I know that they loose their temperature down the straight quicker once they have worn but is the effect really that noticable in racing?
Well it only really is noticable if the inside of your tyres (as in, within the tyres - not the inside part of the contact patch) is running cooler than the outside. Then the tyres could cool down as much as 3-4deg down the straight. By the time you get to the corner, they are at optimum temp and then they heat up again and drop down the next straight and so on. I suppose you could say their temperature is just more sensetive to friction or lack thereof.
Interesting. Maybe higher temperatures are just less stubborn to change? A 100 degree tire will naturally cool off more rapidly than a 50 degree one. Easier to slide and superheat an overheated tire as well.
No, I'm not a drifter. I'm just out for more tyre compounds - which I believe we will get in any case.
As for your demo status, and having driven an S2 car - if you own S2, please use your license name and WEB password on the forums. If you don't and "played it at a friend's house", get your friend to come here and clear your name. Otherwise people will be left with the impression that you cracked the game - not a good thing for you.
None of that needs to be directly modelled though, really. Just some man made curves will continue to suffice.
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