rF2 PSI

Why is there no emphasis on tyre pressure in rF2? The tyre app only shows surface temps which are pretty useless tbh, it's not telling me if I'm 10 PSI over or under inflated or anything. I was led to believe this sim has the most advanced tyre model yet I can't find anything when searching the web about optimal tyre pressures for each compound of tyre or anything, people just say it affects wear rates. In other sims it's pretty important to have the correct pressures or the tyre doesn't have correct contact patch with the road (AC/ACC...erm real life)



Do rF2 tyres exist in a bubble that their pressures never change only the surface temps?

If I'm wrong and missing something here I do apologise and would like to learn

 

You can learn about pressures when you visit the garage, it shows realtime pressures:



Surface may be useful to get a better idea how tire pressure is distributed at contact patch, and various other stuff. It is actually a bit of a cheat already, even if it does not have a "bingo" message for perfect tire inflation pressure.

Also there might not be such thing as perfect tire inflation pressure, as tire will always have changing load. And optimum pressure doesn't seem to be such a switch for good performance as it is in other sims. Of course there probably is best pressure, but it seems to give various tradeoffs such as softer is easier, stiffer is harder to drive, a lot of people say that lower pressures are always faster in rF2, but I think that could be placebo, and it might be just easier.

Speaking of placebo... there is an optimum pressure value written in physics .tbc file, however, oh surprise - only AI uses it. Player uses .tgm, which I can not work out how optimum pressure is managed. There seems not to be such value. And optimum pressure might be whenever the tire has perfectly optimum contact patch pressure distribution... It probably should be aimed to be so for the moments whe ntire works the hardest, at the most important parts of the race track.

Also pressure probably adjusts a spring/damper effect of a tire (well I think that it definitely does that), and that has a an effect for responsiveness, maybe low pressure might have perfect contact patch pressure, but would be too sluggish ? I wonder.

 

Yeah that's about the conclusions I've come to aswell. I wonder if a dev could chime in on it, it seems strange to me that we aren't working towards a pressure thats influenced by driving style and ambient conditions. Even in F1 Pirelli tell the teams the optimal working ranges for the tyre pressure, whether the teams can keep them in that window is another story, but they at least have a figure to work towards. The way it's handled in AC and ACC is exactly how it is IRL, there's a YouTube video of I believe Goodyears new tyre and they take it around a track, it has sensors in each tyre and display a dash like ACC tyre app telling you in a colour coded visual with numbers what each tyres pressure is at. And the results were the same when the tyres were over inflated after a lap or 2 as AC, car feels less planted, slightly slower times etc, if I can find the video I will post it.

 

My mistake was Michelin, found the video

 

Hmmm I have the on screen wheel disabled because my real wheel is right against my screen, any particar car that shows this? A new GT3?

 

You have to run laps and then look at pressures and temps in the garage. You want to start at a low enough pressure that when the tires build up to optimal pressure it is not going to over inflate. So let us say we are running a tire that the optimal pressure is 52 psi and your tire builds up 10-12 psi. You will want to start you cold psi at around 40ish. Now once it builds up to 52 psi your tires will be worn somewhat but you are getting the most out of your tire this way. You will end up being faster on worn tires than if you built up to 60 psi sliding around because it is actually overinflated. rF2 simulates this very well. You just have to do some work to figure out about where the optimal psi is at for best grip.

 

But the OP was asking how to determine that, as in your example, 52psi is optimal. It's great to say a number, but how do we discover that information?(not slapping you down, I want to know as does the OP)
-thanks

 

Yeah that's the way I do it in other sims like AC, it's kind of weird to me that the compounds optimal pressures aren't listed anywhere in the setup screens, even road cars have it. All this testing just to basically guess the right pressure is a bit dumb tbh. In AC if I do 3 laps and it says my optimal pressure range is 23-25 and my pressures are over inflated signified by the numbers being red and about 28, I know to reduce pressures by like 3 to bring me into normal range for at the limit driving at that track/temperature combo.

 

There is a program developed by third parties that can help you. It's called car stat. It brings very detailed information about tire temperatures. I think I remember that it also has pressure information, but I can not guarantee it.
https://forum.studio-397.com/index.php?threads/carstat-2-3-a-question-of-setup.58106/

 

Optimum tyre pressure depends on how and where it's used. rF1 used TBC tyres which had a simple load-dependent curve for optimum pressure, rF2 models the physical tyre so there isn't a simple value you can see. Since we can't talk to the manufacturer we can only deduce the optimum through testing.

Nearly every guide you read that talks about optimum pressure is based on a game.

 

Just to continue now that I'm at a keyboard, @kraM1t the pressure adjustment talked about in the video above you can replicate by using telemetry. Although we only have the rubber temperature at the inside, middle, and outside of the tyre, if you look at the rate of change of those temperatures during cornering you can soon tell whether your pressures are higher than optimal as far as having a 'flat' tyre surface - but remembering camber thrust is important for cornering, so camber adjustment is also important, but then that has to be balanced against straights (or less extreme corners) depending on the track characteristics (how many corners, how many straights). So even if you have some target, at a particular track you'd probably need to test and adjust based on overall laptimes. That includes braking especially, where the front tyres can have quite an increased load - so if you adjust pressure based on that moment, you're probably running too much pressure for 'optimum' cornering.

I just don't think it's as straightforward as people think (and games have made out in the past) as far as having some magic target figure. The TBC files the AI use, and the player used in rF1, exposed the sort of figures that most games used (and still use) in their tyre models, but that's very different to the method employed in rF2.

As for F1, Pirelli mandate a minimum pressure for safety. The teams basically all run at that minimum pressure because lower pressure gives more grip - and those sidewalls are very big in comparison to street tyres, so when it comes to grip it shows that contact patch area trumps nearly everything else (of course their suspensions are tuned to match the spring effect at those low pressures, but when the minimum is suddenly raised by 1 PSI overnight they don't seem to lose their ability to cope, so I doubt that's a massive issue). I don't think Pirelli provide an 'optimum pressure'.

Passenger cars have an optimum pressure label, but that's often a few PSI lower than the tyre manufacturer recommends (softer ride, more comfort, car seems nicer), and even those manufacturer recommendations are for even wear - not necessarily the pressure that will give you the best times racing around a track.

 

And here i am just driving and feeling what is happening to the car and adapt. No fancy HUDs or info anywhere. : D

 

v8 supercars Neil Crompton use to say 30 psi was optimal. Not sure if modders even tell us what the optimal tyre pressure should be for their mod its like its secret squirrel. It should be common knowledge IMHO. Does S397 even give out this info on its mods. Maybe the new UI might cater for this in the future.