Strange spin when rejoining from grass/off-road

I found a short video clip of cockpit view, and the speed was very accurate. When I returned to the track, it happened to be 50M/H. I almost drove out of the track in a straight line, and then the car kept turning. I tried to correct the direction several times but it didn't work. As you said, I hope to increase the friction of the grass/kerb/sand.

I don't understand. Could REIZA not have noticed such a significant issue

 

The reason might be that people just don't understand car momentum?

He is already in an oversteer slide, with a rear engined car, going down a hill on bumpy grass patch. No throttle or brake is applied, so the only thing trying to stabilize the car a little is the rear diff preload.... But with the heavy rear of that car? Yeah, good luck stoping its yaw movement, even on tarmac.

Then he hits the tarmac with lighter front, at significant slip. So ofc the front will slow down and throw the heavy back around, while front acts like a pivot point.

This is exactly how I would expect this car to behave in this situation...
Yes, there are quirky AMS 2 behavior, but this is not one of them.

Could grass be more grippy? Possibly, but I don't feel that would change much in this situation. I also don't feel that grass behavior is that different from other sims. You cannot react to the car movement once it hits grass, that's already too late. You need to prepare for the shift in grip level, and try to even the load on tyres as much as possible (so no heavy turning, braking, accelerating).

Countersteer is not magic. For car to regain control you really need the friction of rear tyres to stop rears lateral movement. You countersteer to keep the front in sync with rear until that happens, but you cannot directly affect what rear of the car does... and if the rear moves faster than what the front tyres can compensate for (becasue of maximum steering angle), then you will spin.

 

If you had read my previous description carefully, you probably wouldn't have given such an answer. The strange thing is that no matter how you operate, the car must complete the entire rotation process like an unchangeable program before stopping, and my operation has no change to the car during the process at all. However, similar situations do not behave in this way in other SIM.

We have also discussed the situation that the front tyres regain friction before the rear. At low speed, it is not realistic for the rear of the car to suddenly accelerate and rotate. Even after the rear tyres come into contact with the track, the car continues to rotate for a while, which is also strange.

 

I’m really starting to think that the only driving experience you have is from other sims ? ( this is a question )

as you don’t seem to appreciate that a 1 tonne mass moving at 50kph isn’t going to stop on a dime .

I highly doubt you would walk in front of a car on the road travelling at 50kph only leaving a few metres of distance between you and it .

 

Speed is not momentum. Because of weight, even at the same speed, the rear has more energy than the front. Because of this, it takes longer for the rear to stop, becasue it takes longer for the rear to dissipate all the energy.

In your scenario the front hit the tarmac first... so not only does the front has less energy to get rid of, it also has advantage of having much better grip.... ofc the front will stop first and throw the back around.

I also don't think the rear really accelerated. Yes, the whole car started to rotate, because the front is now a pivot point.. but I'm not sure its velocity compared to the ground increased. Yes, the whole scene started spining more, but that's becasue you're in a fixed chase cam, so if the rear rotates, the camera will rotate even more, which might give the impression that it sped up.

Check the 8 minute mark

See how little rear movement ends in a full 180 degree spin, because the tyres are just unable to stop the heavy rear. With the front slowing down and acting as a pivot point for the whole car... Full on dry tarmac...

Its really not hard finding videos of Porsches spinning this way, as that is typical for rear engined car. Once rear goes, it goes....

 

Even though I also have noticed that it has felt a bit strange in the past especially (can't remember the last time it happened to be, could be before 1.6), I personally can't say is it unrealistic or not. Even comparing to other sims would be really hard (to able to replicate exact same inputs/car/track/condition), but yeah, it definitely feels that you can regain the grip faster / have more friction in such situations in other sims I have driven a bit more, but it could be combination of modelling different brand tires/different kind of stiffness/suspension etc. a

In any case, looks very much like AMS2 "lazy spins" to me (and in quite low speed even) :
(around 5:56 mark):

 

I think we need a different example as the one provided can be explained and sits in line with real-life physics.

With the unrecoverability stated, I'm also assuming that drifting in AMS2 is not possible since allegedly car need to "complete the entire rotation" (I can't drift so I can't attempt it as an evidence for or against the thesis).

I'm not saying that grass/spin simulation is perfect or there's something predefined in the game code when spinning, but the provided example 100% meets my expectations for in-game physics and shows no sign of anything blatantly wrong.

 

What if I told you that I have over 12 years of driving experience? It's become meaningless, because you have already assumed that everything about AMS2 is correct and cannot listen to others' opinions. What I see is the only thing you do is to make incorrect assumptions instead of truly discussing the problem itself.

Not exactly. In your video, the car rotates at a constant speed and gradually slows down, without a sudden increase in speed. In fact, as the car rotates, there is a tendency to stop. And the situation I encountered was the car suddenly accelerated when the front tyres touched the track, and then the rear tyres touched the track, without obvious deceleration, but gradually stopped after the vehicle completed half a circle of rotation. This is also the reason why I feel like a script spin. There is no obvious feedback on the operation, and there is no obvious feedback on the rear friction change, seems only because of the front tyres are on the track and the rear tyres are on the grass, and the program determines that SPIN should be applied, so the car spins.

 

I don't know enough detail to know if you're correct that the physics are weird on this matter, but I am pretty sure that there is no thing saying "APPLY SPIN" in the program. It's just some emergent result of the game's physics, whether they're realistic or not. Just that point was niggling at me.

 

Is it 12 years of experience in driving GT Class cars on circuits? Or 12 years of experience driving road cars? Because those two are not really comparable (I have 17 of the latter).

If you want to discuss, then discuss. How do you think the car should behave in the situation? Expand, don't just say 'AMS 2 is wrong'. So far you're only repeating the same statement again and again. Why shouldn't the rear slid around the front if it has grip for shorter period and more momentum?

And once again, I don't think the car sped up... the rotation did, because there is a pivot point once the front is on tarmac, but the relative velocity of the rear relative to road surface look to me to be decreasing once you hit the tarmac.

 

To be fair, Icy did expand a little bit, but only to the point of claiming that other sims don't behave this way, and that one is supposed to be able to regain control of the car. But compare that amount of "expanding on the claim" to the half dozen detailed posts with physics explanations in this thread that make a case for why this could be seen as reasonable physics behavior in real life. The burden of proof has been skewed quite a lot in this discussion.

The burden of proof should be on the one making the initial claim, not on anyone else who wants to participate in the discussion.

A video showing a real-life spin where the car is able to regain control in a way that is satisfactory to Icy, followed by a video showing if the same is possible to do in AMS2 by matching the conditions as closely as possible, should be sufficient evidence.

 

Indeed, when I posted, I didn't think too much about it. I just hoped to discuss this issue with people who have similar experiences, hoping that REIZA could attract attention and make the physics simulation more realistic. Although my video is not very complete and accurate, some people seem unwilling to discuss the issue itself, just constantly guessing and emphasizing how correct they are.

 

Here is similar dynamic in ACC..
See, how the yaw speed is relative small, it is still a slide, but it isn't getting worse... until the rear hits the the outside of the track... and it isn't even grass....
That changes the grip levels, and suddenly the front is stoping faster than the rear, causing the car to rotate...

 

im sorry , but you seem to be fishing for support, and seem closed off to the possibility that your claims are flawed logic .

let’s break it down .
1 . OP is claiming that game has pre determined spin code ( wild theory)

2. OP submits there evidence in form of very short video only showing a portion of scenario. ( Flawed evidence as chase cam increases speed to maintain perspective)

3. OP repeating that main argument is other Sims don’t do this . ( flawed reasoning as other sims are proven to not be a good reference and some even do the same )

4. OP accusing anyone with a counter argument as not willing to discuss the issue. ( despite many different users giving very sound responses that are backed up by good evidence and irl experience, and are only trying to help the user understand the physics behind what’s occurring.)

so I think OP needs to give a much better example to prove claims , that isn’t based off what other sims do , as that is not valid or accept that if almost all disagree, then perhaps it’s not a valid issue.

 

Your situation is quite different, and if you observe carefully, there are two differences. I think this is the important reason why it gives me the feeling of 'script spin'

1. During the rotation, the front tyres of continue to slide, with a sliding distance smaller than that of the rear, and have not completely rotated around the front as the axis.
In my video, the front hardly move much, which gives the rear acceleration and a strange feeling (does this mean that the front tyres of GT3 in AMS2 have excessive grip? In fact, many times when entering a corner, you can force the steering wheel to make the rear of the car rotate, and the front will hardly slip, which doesnt work in other SIM)

2. The speed of the car losing control in ACC was significantly higher than in my video, but unfortunately I did not record the first half of it rushing onto the grass. At that time, the speed was less than 80KM/H, almost straight out, and then the car began to inexplicably rotate. Finally, when it spin, it only had a speed of 50KM/H. At such a low speed, I turned the steering wheel, the car show no feedback at all, which is also an incomprehensible point.

Anyway, thank you for giving examples and understanding the problem carefully. Unlike many people who don't even understand the situation seriously and only teach you what they think physics is.

I have already explained that the video is too short and I did not record it completely. I have tried my best to supplement the situation with language descriptions.

However, I see that you and many others are not fully understanding the problem, but rather making assumptions. Even though I have repeatedly replied to your questions, you have not considered your own mistakes, and have not analyzed the problem seriously. Instead, you continue to make irresponsible guesses and maliciously believe that I will 'walk in front of a car on the road traveling at 50kph only leaving a few meters of distance between you and it', which is ridiculous.

And I don't think you are open and logical.
In your reply, you made too many irresponsible speculations, such as

1. You doubted me with the point that the speed is too fast, thinking that the speed exceeds over 100KM/H. You didn't even know that the first gear of the Porsche 992GT3 can only reach around 80KM/H at most, but when I found the video inside the car and confirmed that the speed was only 50-80KM/H, you skipped this like it never happened.

2. Suspect that I only have simulation game experience and have not driven a real car.

3. Does almost everyone disagree? Some people replied that they thought there was a problem, why did you ignore them directly?

If you are not prepared to listen to others' descriptions, but only identify problems based on your own assumptions, it's meaningless. I think you just want others to admit that you are right, not solve the problem itself.
Let's end it here.