Physics discussion thread

I'm just trying to do this as correctly as possible in my area of expertise, in ways that are accessible to me and most players...And to do this, I suggested on the forum that other players conduct a test under the same conditions. This is the simplest test, I think you understood it perfectly =)

 

I have got no idea what your talking about, but I just know that such a test will become irrelevant in time .

 

Okay, I totally get it.

 

Those "tests" only make sense if they are made in controlled environments. If you ask 3 different drivers for their opinion of handling you'll get 4 different answers and won't get any conclusions. Guaranteed.

No sim out there is anywhere near real physics due to huge computing power required to calculate various things hundreds of times per second, whereas real physics are dynamic all the time.

Just choose your poison and enjoy the driving where you like it the most and live happily ever after

 

That reminded me of a older video from RaceBeyondMatter where he was talking about ABS in context of iRacing where you don't want to lean on too much even with the ABS activating, you end up having understeer with the amount of load on the fronts kinda fluctuates while ABS is doing it's thing.

IRL, I have understood you tend to want to lean on the ABS a bit more and use that benefit on something like GT3 to be able to both slow down and also turn at the same time (at least some) with benefit of not locking up. I wonder if you lower the ABS setting on AMS2 (it's quite high on default on all cars), you that help with some of the issue on cars with ABS.

 

there’s different systems for race cars vs street,
And knowing how my own road cars behave under abs activation, they don’t slow up as fast as they would be without activation that doesn’t lead to locking.
The Abs system actively releases brake pressure to avoid locking in a pulsing fashion , it is just a pump actuator.
This is counterintuitive to peak stopping performance, but still better than locking and going straight on into an obstacle with speed not reducing of course, and stopping a few meters later than perfect with abs is still a better outcome in an emergency.
your not worried about making an apex then .

 

Going back to physics discussion. One thing I've noticed on the V1.6 train code, camber changes on most cars seem to have little effect on the handling and balance of the car. Changing the camber, signficantly doesn't seem to swing the I,M,O temperatures on the tires as much as one would expect.

On most production cars, IRL, if you change the camber 0.5 deg you feel a shift in the balance of the car during cornering. -1 deg of camber in the front can change the balance from slight understeer to slight oversteer (depending of the suspension type, McPhereson vs Double A arm). With the current code train post V1.6, I've noticed that massive camber changes doesn't seem to make as much difference on the balance of certain cars. Eg: Ginetta G40 GT5, GT4s. This feels similar to the issue I brought up earlier about slow bump and rebound shock changes not having as much of an effect on the transitional balance of the car during corner entry and exit.

Also, while I appreciate what the Devs has done with the tire and physics update on V1.6.9. Personally I would like the slick tires to be a bit more forgiving and feel just slightly more "elastic". Not much more than what we currently have, just a tiny smidge more. What I mean to say, is when driving a car at the limit on track, you can start to lose the rear at times but with a neutral balance setup, you usually have ample time to catch the slide and bring the car back without it snapping on you. The whole ordeal feels like an elastic band being stretched when you start to lose the rear of the car. You can usually slow down your inputs, countersteer a bit and gain control. The current tire model, still feels a bit on the knife's edge to me although it is vastly superior to what we had pre V1.6.9.

Perhaps something the devs can look at when they get the chance during a later release. Either ways, super grateful for all the updates that continue to make AMS2 so much fun.

 

Those camper changes do affect the I,M,O temps (you have to drive few laps though to see it) on cars I have driven more recently (none of those what you mentioned though). I'm using this little tool to monitor those things always when not using VR: Omitool2 (for SimHub) and often do adjust the camper, sometimes quite a bit to get those temps to ideal range. It sometimes do require quite few clicks to do it...

the setup tweaks definitely have less of an impact (per click) on AMS2 that on something like rF2/LMU which I have played more.

IMO the current tire model doesn't feel on "knife edge" to me, it just feels somewhat flat, where the grip falloff is not dramatic until you are clearly pass the peak grip and reach that cliff edge, which then is sudden and really hard, often impossible to save it (which feels bad especially if it's a slower corner with a slower spin).

I know I would enjoy it even more, if the slicks especially would be a bit peakier, feeling more bitey with sharper drop off sooner, but the tires would be able to regain grip easier/faster unless you really over do it (but also in a way that you can't abuse this, that there would be reprecussions with overheating if you start to do it too much, even on same lap on cars like modern F1 as that is the car also IRL). I think the "very wide slip angle" feeling on AMS2 might be because of this grip drop-off isn't that sharp initially, you can kinda still slide the rear at times, as long as you pre-emptively avoid going beyond the cliff (you kinda have to find and memorize it though).

When analysing something like rF2, it has that kind of tire model on many cars (especially the newer stuff from the studio), but it isn't/wasn't perfect there either because it was too abusable in skilled hands, who were able use those traits to get better lap times in both qualifying and race (not sure what it is missing, maybe some more slightly longer term impact of doing that maybe). On LMU, with the 0.9, the changed the tires to be super peaky, allowing only little slip angles before there was dramatic drop off... which then got adjusted again with 1.0 and 1.1 back to being more lenient, but still being more peaky and harder to catch/save than it was in rF2 (not saying it's still perfect and I don't find it nearly as enjoyable as rF2).

ACE seems to have a tire model also that has such traits, but I guess also there the "point of no return" is vague and you end up having to drive pre-emptively to avoid it.

ps. the FFB of choice really impacts on how I do perceive the grip, the default ffb is good with giving somewhat earlier warning on grip levels, but it also can make me feel that I have less grip available that there actually is to utilize. I tend to even switch the FFB I use depending on car/class, for example I do like the defaults on something like GT3 (feels dynamic, less "flat" with grip levels), but not so much on something like Group A or Group C where defaults I feel like I'm struggling for grip all the time without tires ever really biting on the tarmac (the other option I currently use, depending by car, is the Karsten's latest custom).

 

I've been using the in game hud for O, M, I and what I'm saying is while it does change some, it doesn't feel like it changes as much as it should. Take a probe tire pyrometer to the track and measure temperature across the tires and you'll see what I'm trying to say. 1 deg of extra -ve camber change can have a noticeable change of a few degrees across the carcass. What changes even less is the oversteer/understeer balance for more cars with camber change.

I think we're kinda saying the same thing, knife's edge vs falling off a cliff. That sudden loss of traction, at which point you're just a passenger along for the ride. I, for the most part, like what they have done with the current tire model update, it feels like some of the less forgiving compounds you can run in real life. I'm not comparing it to other games, but to what happens IRL from my personal experience.

Also, I'm not referring to what the FFB is communicating. I'm not someone who gets the feeling of tires gaining or losing grip from FFB. So saying FFB feels "flat" or "floaty" or "peaky" is basically lost on someone like me. I'm one of those people that doesn't heavily rely on the finer details of FFB to tell me what the tires are doing. FFB translation doesn't come naturally to me, as you don't experience such things in real life, especially with cars that have power steering. I drive more based on visual queues, intuition, muscle memory and knowning when I do X input I should get Y result. What I feel comes naturally from my experience IRL. That being said, I also understand a lot of sim racers are more atuned to the minutia of FFB effects that tells them what the car is doing.

When I see and feel the car start to oversteer, the timing of how quickly and suddenly it happens is what I care more about. Is it sudden or more progressive. Does it feel natural or not. Does it feel more "elastic" or like an ON/OFF switch (Eg: AC). Can you play with the car as it starts to experience oversteer, if so to what degree before the backend comes around.

You can see on my track video where the rear starts to step out going into T3 at Pueblo motorsport park, how you can counter steer to catch the car and still carry speed through a turn. This happens a few other times during the lap.

 

• While the 2 Mini Cooper's are in a custom livery, they are running standard in terms of their performance.
• Lap 13: Wet tyres very quickly going to jelly and force a pitstop earlier than ideal, and earlier than the AI can manage.
• Lap 40: Should there still be visible puddles/damp patches and a "Moist" track condition when there has been no rain for hours, 33 Air, 50 Track temp and an 18kph wind?

All the best
Andy

 

I am curious what are peoples thoughts on this.
When driving Mount Panorama on exit after cutting the inside wheel always spins. I have tried to go softest ARB and suspension and ajusting diff preload, but outcome is the same. In my example I used GT3 vette. But I have tested multiple cars and classes now, and my observation is that most higher powered sportscars(GT3, GT1 2005 etc) have this behavior. Sportscars with less power, like GT4, also have this but not as pronounced. No wheelspin or barely noticeable on prototypes. LMP2 G2 have really nice traction there.

My issue is that when looking at IRL onboards(I am not gonna reference them here, you can look it up on youtube, there is plenty), especially with telemetry, they can go 100% throttle and you can see in telemetry or by audio that they have stable engine RPM, and you could assume there is no wheelspin to extent of what I have. So what causes this? Maybe track model has more camber or sharper crest then IRL that unloads the tire? Is it maybe setup or physics related?

 

Yeah I've noticed the same thing as well. I don't recall if it happens in other games or not, but I'm pretty sure it didn't occur in PC2 because I only recall needing to compensate for it when I started playing AMS2.

 

it’s a valid observation I feel.
It doesn’t come across as unnatural behaviour, but if it’s not normal for some cars as described, or presented. Then it’s something..
it could be a acute camber of track , it could just be slight physics sensitivity to centre of gravity or suspension geometry, or perhaps it’s just the Traction Control modelling, which is known to be a bit generic in implementation.

 

Is there anything you know about working on the brake mechanism and traction?
In general, I'm not satisfied with the traction and weight of the front axle. I can't decide which component makes me feel bad. You simply can't feel when braking that something wants to brake the car. It blocks immediately and there's no contact between the asphalt and the rubber. It's as if there's not enough friction. Or there's not enough weight on the front axle that would hold the car down so that it doesn't just slide, but also slows down and stops. It bounces outwards in high-speed corners and just doesn't want to grip. So in general, I'm not satisfied with the way the front axle of cars is modeled.

 

That omitool2 is a masterpiece as overlay

 

I was wondering whether the TC and ABS systems for different cars in the sim work according to the cars actual systems or is it just the games inbuilt TC and ABS systems working the same way across cars.
Made me curious because a formula car from the 1990s has the same default TC and ABS settings (6 and 8) as a modern GT3 car and in general, the systems seems to be quite linear and too intrusive. Asked this in another thread but couldn't get an answer as the forum has been a little quiet recently. Thanks!

 

I think it is just a generic implementation that is not tailored to each car.

 

I feel like that's a big omission, no? I'm not sure how much accurate systems would impact the handling but it does feel a little 'off' in some cases.

 

Hey all, haven't seen him here for a while, is Crimson Eminence still around?

Yes it is, I think it is also active when it shouldn't be, it seems overly sensitive and kicks in even when the car in game is not showing TC as being active, like when in th pits with the pit limiter on for example. It needs recoding me thinks.