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Javaniceday
27-02-2019, 19:41
I think the idea that there should be .5 C difference between inner and outer tires is pretty standard knowledge. But more advanced, what clues should you look for to see if you should add or remove camber?

cpcdem
27-02-2019, 23:33
In my opinion, do not check temp differences at all. Just try it with less and more camber and see what suits you best, for the track you want to race at. The rule is that the less negative camber, the more acceleration you have and the less cornering speed. In tracks like Monza and 24h LeMans, decrease negative camber to as small value as you can handle, especially in rear tires. For other tracks, the difference is quite small, but you can give it some test.

supremedk
04-03-2019, 23:51
I agree with that^^^^^^ the tire temps in this game do not correlate properly, across the tread, to camber changes. Do some testing with a low camber and note your lap times, then high camber and then work your way back in small changes and see how the car responds.

Your optimal camber will change with tire compound, track, weather etc. but you will find a window that will work good in most conditions.

Urban Chaos 2.0
08-03-2019, 18:54
As in real life: Different tyres respond differently to the same temperatures, and heat up and cool down differently. They also behave differently when exposed to the same environmental factors. You need to be concerned with temps only with regard to YOUR particular car, driving style, tyre and track conditions, etc.

Javaniceday
08-03-2019, 22:09
I agree with that^^^^^^ the tire temps in this game do not correlate properly, across the tread, to camber changes. Do some testing with a low camber and note your lap times, then high camber and then work your way back in small changes and see how the car responds.

Your optimal camber will change with tire compound, track, weather etc. but you will find a window that will work good in most conditions.

So trial and error is the only way, really? Any patterns that you've noticed? For instance, I've heard it said that in places with fast corners you can adjust the camber to go faster. But how this relates to aero and suspension changes is still hazy to me.

cpcdem
08-03-2019, 23:45
Personally I would ignore aero and suspension changes (in the sim), but what you said is true, more negative camber helps with cornering. It's a compromise, more negative camber for faster cornering and less top speed, less negative camber for better acceleration and top speed, but makes cornering more difficult.

Bealdor
09-03-2019, 08:36
So trial and error is the only way, really? Any patterns that you've noticed? For instance, I've heard it said that in places with fast corners you can adjust the camber to go faster. But how this relates to aero and suspension changes is still hazy to me.

No it's not and I disagree with some posts saying tire temps don't correlate correctly with your camber angle.
When I wrote the manual for PC2Tuner I did a lot of data collecting and I can confirm that the temperature gradient does change according to your camber and is indeed a good tool to optimise your car's cornering (and to a degree braking and acceleration) ability.

I also disagree that you should ignore suspension changes wrt camber.
During data collection I specifically tested the effect of suspension changes on dynamic camber angle change and the conclusion is, that the effect is working correctly ingame.
The stiffer your suspension (springs+ARBs) the less dynamic camber angle change you'll get (because of the lower roll gradient):

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The data shown in the image above was recorded with the same car, at the same track, after the same amount of laps.
The only difference was the ARB stiffness and therefore roll stiffness of the car.
(btw. the values shown above are functions of the temperature gradient across the tire, not the camber angle)

In other words: The stiffer you suspension the less static camber you need to set and vice versa.

Your tire temps are the most important indicator to check if your suspension setup is correct/balanced (not only for camber).
I tested the effects of a lot of different suspension settings (camber, overall roll stiffness and roll stiffness distribution, ride height and rake angle, etc.) purely based on tire temperature data from the game and they all worked like expected.

Zeratall
09-03-2019, 12:53
Just to back up what bealdor said, the tire temps are telling you exactly how much energy are going into the tires, and more importantly where on the tire that's the whole point of doing I-M-O. To provide some data on this point I went ahead and did some data laps.

Car : GT3 Mcclaren
Track: Barcelona, Temp

-1 Camber: Yielded 2 Degs of Temp Gradient
https://cdn.discordapp.com/attachments/477363336502181896/553931234019901447/unknown.png

-2 Camber: Yielded 7 Degs of Temp Gradient (Ideal)
https://cdn.discordapp.com/attachments/477363336502181896/553932522011099146/unknown.png

-3 Camber: Yielded 10 Degs of Temp Gradient
https://cdn.discordapp.com/attachments/477363336502181896/553933770345152523/unknown.png

-4 Camber: Yielded 12 Degs of Temp Gradient.
https://cdn.discordapp.com/attachments/477363336502181896/553935255740874753/unknown.png

Note while between -3 and -4 Camber the Overall Grip Metric is relatively equal the amount of tire wear between -3 and -4 camber was drastic.

cpcdem
09-03-2019, 13:38
No it's not and I disagree with some posts saying tire temps don't correlate correctly with your camber angle.
When I wrote the manual for PC2Tuner I did a lot of data collecting and I can confirm that the temperature gradient does change according to your camber and is indeed a good tool to optimise your car's cornering (and to a degree braking and acceleration) ability.

I also disagree that you should ignore suspension changes wrt camber.
During data collection I specifically tested the effect of suspension changes on dynamic camber angle change and the conclusion is, that the effect is working correctly ingame.


My suggestion was not that camber does not affect temps, but that that there's no point checking the temps, regarding achieving better cornering speed/acceleration-topspeed balance. In other words, that achieving the suggested temp distribution will not guarantee a better result. Do you disagree with that?

Bealdor
09-03-2019, 14:00
My suggestion was not that camber does not affect temps, but that that there's no point checking the temps, regarding achieving better cornering speed/acceleration-topspeed balance. In other words, that achieving the suggested temp distribution will not guarantee a better result. Do you disagree with that?

Yes I do, see Zeraxx's post as example.
I do agree that there's not one truth/temp gradient that always gives you optimal performance, however, saying ignoring the temp gradient is the way to go, is the wrong conclusion imo.
Since there's no way to measure contact patch sizes directly, using the temperature gradient is the only tool you have to optimise cornering grip based on data.

More camber = higher cornering grip is not an absolute truth, as you can see in the graphs Zeraxx posted.

cpcdem
09-03-2019, 14:43
Yes I do, see Zeraxx's post as example.
I do agree that there's not one truth/temp gradient that always gives you optimal performance, however, saying ignoring the temp gradient is the way to go, is the wrong conclusion imo.
Since there's no way to measure contact patch sizes directly, using the temperature gradient is the only tool you have to optimise cornering grip based on data.

More camber = higher cornering grip is not an absolute truth, as you can see in the graphs Zeraxx posted.

I assume you guys are using the TyreGrip telemetry parameter to acquire and calculate the average grip levels? When I tried using that, I could not get results consistent to what I was feeling while driving, or with my lap times, but I maybe made a mistake. This info is indeed marked as obsolete ("kept for backward compatibility only") in the docs though.

But my point is that using the "optimal" camber does not make you faster. See for example the WR for the McLaren GT3 in Watkins Glenn (a track with a lot of medium speed cornering requirements), which is currently the 2nd fastest overall GT3 time there.among 2500 total times in this track. The guy is using zero (0,0!!!) rear camber! (I know, he is also using more downforce, but still, zero camber...) But the sim gives plenty acceleration benefit to zero camber, so that he can be that fast with it. For me, zero camber was too hard, made the car too oversteery for me, but with using -1.0 camber I managed to get very close to him, was just losing a few tenths in the straights to him.

Btw, I am not saying zero camber is always the absolute fastest, I am sure that somebody else given enough effort could manage to get a better time than his, with a more normal camber setting, but still, when you see the current top 2nd/2500 times using zero rear camber in a twitchy track, I think it's hard to argue that the optimal camber is around -3.0 or so.

Zeratall
09-03-2019, 16:00
I assume you guys are using the TyreGrip telemetry parameter to acquire and calculate the average grip levels?

Nope, we aren't using that channel anywhere in the software as you mentioned it not used in the new protocol. To measure Grip were using the standard telemetry channels you can find in any sim and were performing some math on it.


But my point is that using the "optimal" camber does not make you faster.
I will strongly disagree with you on this point. I already proved with data from my post before that the closer you are to IDEAL optimal camber the more lateral acceleration the car is pulling. The reason that does mean faster lap times is because if were pulling more lateral acceleration through a corner it means were carrying more speed through that corner and most likely if were carrying more speed the corner it means a higher exit speed.

I wouldn't go off of time trials for validating results. Time Trials aren't reset from patches so sometimes your running a ghost that had a stronger car than you, or has a different line. Compare apples to apples (your own time).

blinkngone
09-03-2019, 18:39
Nope, we aren't using that channel anywhere in the software as you mentioned it not used in the new protocol. To measure Grip were using the standard telemetry channels you can find in any sim and were performing some math on it.


I will strongly disagree with you on this point. I already proved with data from my post before that the closer you are to IDEAL optimal camber the more lateral acceleration the car is pulling. The reason that does mean faster lap times is because if were pulling more lateral acceleration through a corner it means were carrying more speed through that corner and most likely if were carrying more speed the corner it means a higher exit speed.

I wouldn't go off of time trials for validating results. Time Trials aren't reset from patches so sometimes your running a ghost that had a stronger car than you, or has a different line. Compare apples to apples (your own time).

He is referring specifically to Kramarsky's patch 7.0 run at Watkins Glen GP, a 1:40.641 so apples to apples as far as patches go. Maybe something happened to the McLaren 650 S in the last patch? If you would have the time please check it out and see what you think.

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Bealdor
09-03-2019, 19:21
The reasons why this setup works in TT(!) are most likely the following:

1. Front camber is close to optimum, which gives great cornering ability
2. Suspension setup is quite understeery which compensates for the lower rear grip somewhat
3. Low rear camber gives good acceleration and braking performance because of increased contact patch area when driving straight
4. You have infinite tries to get that one perfect lap out of the car. Nobody would drive such a twitchy car irl.
5. Tire wear is not an issue in TT.
6. Top speed is not an issue in most GT3 cars on this track because the straights aren't that long.

Using less camber on the rear axle is quite common irl too.
I can't rule out that PCARS 2 may underestimate rolling resistance and therefore favour low camber sometimes, but from the data we gathered I'd still say that a realistic suspension and allignment setup will be the fastest option under realistic circumstances most of the time.

Gav88888
15-03-2019, 12:59
Personally I think PC2Tuner is a great tool for making a realistic car setup, some people can use a setup like that, others can't, and I have spent a lot of times using real world principles to setup my cars in pc2tuner and its helped me a lot, even to the point of being really anal about what values i was seeing and trying to get it all perfect, but tbh I am just as quick when I don't use it, and sometimes quicker, plus I can quite quickly tune a car now just by driving it, as I find it can take a while adjusting the settings in pc2tuner each time you change a spring or damper value etc and the setup process takes too long...

I also know some of the top Tier1 guys in the AOR GT3 league don't use pc2tuner as it makes the cars too safe, but other guys do use it with good success.

I also did testing with camber myself, I can run a setup with minimal camber settings, another with 3 degrees temp difference, another with 5, then 7, then 10 and lastly with maximum camber settings and I set basically the same time with each setup by tuning the other aspects of the car to suit, so again it comes down to what you want and how you setup the car. On a side note a lot of the GT3 league guys just take the top tune from TT and tweak it a bit to make it work in a race...

There are lots of ways to setup a car.

Zeratall
19-03-2019, 14:12
I also know some of the top Tier1 guys in the AOR GT3 league don't use pc2tuner as it makes the cars too safe.

Not true at all, PC2Tuner doesn't tell you how to tune a car, or give you a specific tune, its merely a way to interpret the data and setup in a more meaningful way (I.E. Crit damping rates rather than less informational spring rates). Also out of our 1k users the largest portion of that are AOR drivers. I know Voodoo is supplying a lot of the teir 1 guys Lambo setups and he is one of the most experienced users of the tool. You hit the nail on the head that tuning has multiple approaches even in IRL the engineers differ on approach. That being said, to get good results you need to know what your doing.