Physics discussion thread

The guy made another bait video, claiming that it's wrong that if you slam the throttle hard mid corner you get snap oversteer, instead according to him you should run into hard understeer. I think he really never drove any powerful RWD Car in his life.

 

I can’t make myself to watch his bait videos, but really? Is is mixing things with fwd or something ??

For sure the car could do that if the diff would be very open (=reason why reducing clutches make the car drive more as in some other sims) or the car would squat a lot and have so weak front etc. (Or a lot of TC I guess)

On LMU the cars are like that a lot more, especially on default setup but even there you do get snap oversteer if you hammer the throttle in mid-corner.

It’s true though that on AMS2 the cars tend to have easier time to have that controlled on-throttle rotation / neutral steering behavior than in many sims, it’s like the window to do that is wider and that is one of the things that makes some people feel it has unrealistic slip angle (I guess they mean yaw angle).

 

This is the issue when you base your sense of realism on other sims instead of on track. It's why I keep saying, it's a fools errand to determine realism comparing one sim to another. All sims should be compared to real life. The more sims get closer to real life, the more similar they will feel. At this point I probably sound like a broken record.

I've come to realize some people use the term FFB and physics interchangably, which is a massive pet peeve of mine. They are not the same thing. Stop doing that! If you can't drive a sim because the FFB doesn't jive with you, that's on you and not on the "physics".

 

This MuscleTalkNoStop just post videos with random gameplay and a lot of stupid "feelings" and poor driving. The last video is just the pinnacle of nonsense about physics.

The best "feeling" feedback about physics is recent video of Lewis Hamilton doing some laps in some simulator saying that the car have so much grip.

AMS2 have the best tyre physics in all sim racing games. By far. Devs are the best. If it's not like other sim, it's not AMS2 flaw. The rest have baked physics as hell, with on/off tyre grip.

Nothing is wrong with AMS2 physics. Just people like to talk crap about "feelings" but few use it's time to use external views and telemetry to check things like turn rate and radius, etc.

 

AMS2 tends to be more rear than front limited in its handling (aka nose to tail), which is reverse to most other sims (description Renato himself gave year or two ago) . Also it seems the diff is setup for more rotation compared to other sims where it’s almost like the opposite, which result in understeer on entry / mid corner and less rotation with throttle.

Most things GM said about weird handling quirks can be explained by those those two things, but his conclusion is that physics is the sim are broken instead…

 

Maybe I am crazy or just not that elite level of sim racer others say is required to realize the flaws, but I can drive largely the same way in LMU and AMS2 GT3s with the only real big difference being the on-throttle rotation you get in AMS2 especially mid-corner.

 

Interesting! Which custom ffb do you use/prefer?

 

Personally, I’ve been using KuKu’s custom FFB for over a year; with a Direct Drive wheel, I can feel everything and drive right at the limit very effectively. I can manage oversteer and understeer well, and I can sense the grip—whether the tires are hot or cold—as well as the G-forces in corners. Throughout all of this, the physics feel very consistent. Compared to the stock Reiza settings, I get more information and handle the limit better; everything also feels more natural at the wheel.

 

100% agreed on both these points. I find people also always gloss over how different in characteristics one company’s tyre to another’s can be. Just because something is different doesn’t automatically mean it’s wrong. Goes back to folks actually basing realism on being in the IRL drivers seat versus other sims.

In my experience the people that are the staunchest “this sim (whatever sim that may be) is fundamentally wrong and broken” 9 times out of 10 have only ever experienced other games from their living room, and have zero understanding of actual core driving physics.

 

It don't help that the most cars are running very understeery setups, especially the GT3s. It's almost laughable how "safe" they are.

I have to drop rear wing from 8 to 0-1, full stiff rear ARB to even get the car to rotate. For some reason it's almost impossible to lose the rear in the GT3 cars. Works great in any formula car but the GT3s have some crazy grip setup that makes it so hard to lose the rear.

 

Aer you sure it isn't just the new TCS = 8 standard value that is causing that? Turn TCS to 1-3 in dry conditions and the moment you step on throttle mid corner hard you can throw away the car, especially on tracks like Interlagos. Of course M4 or AMG is more understeery in stock setup so you have to rotate them more via braking, but Corvette or McLaren are really agile. The other day I was able to get my race pace on Mosport down to low to mid 1:15 with stock setup with how good these drive now.

 

The problem is that any racing sim game runs in itself physics simulation, and 99% of people that drives in some sim don't use the time of gameplay to undestand how sim physics work ingame, and try to guess how real X car works in real.

People need to have fun like Verstappen: do not compare with real cars and have fun and try to be fast o game. Easy.

 

Alternatively it could be also too much brake force that tends make the car understeer easy in AMS2 without obvious feeling of locking up/abs kicking in.

I really don't get the "understeery" claims, because I tend to find the cars to rotate very easily on default setups as long as I long as I don't apply too much brake or run too high TC in cars that have that. EDIT forgot high speed parts altogether, sure, in those the car tend to understeer quite often.

 

No I never run TC I think it cuts in too strong regardless of setting.

Yes in slow/medium corners you absolutely can drop the rear but that often because rear tyre spin. But in high speed corners its seems glued. But like you say the Corvette and Mclaren being rear/mid engine cars you can get those to step out.

 

I can’t follow everything you are writting. What setting will help me to not spin during a corner entry. If i use my lmu trail braking technic, the rear will make my gt3 gen2 to spin the moment i decrease and turn the wheel. This happen mostly in slow corner with default setting and abs to 6 brake sentivity to 50%

 

I thought Reiza had this figured out years ago, but notice the update for more GT1 cars, the suspension is backwards again. I've known the importance of weight ratio for as long as I can remember and it's utmost important, the suspension is to remain the same. You can still soften or loosen the spring rate overall, but try to keep the ratio between front and rear fairly close the same as weight bios of the car itself. You could even test this out with an rc car if you want to test the method and see how they react when you get it just right. Yes, damping will play a factor as well, but watching races in past for so long says you should keep damping fairly soft so the springs can still do their job.
As for GT1, the Saleen S7 has it's springs much softer in rear than the front, which complicates the tune a bit. I have to max the rear and minimize the front to get it balanced. There is no tolerance in this case and only so much I can do for tire wear. The Lister M12 is similar, but much softer and pretty much drags it's back end everywhere. I have to lift it to 90mm to compensate. You can see Ernesto's video up above (great example btw). I hope they fix this in the near future, but the cars are still fun to drive!

 

Back to the topic about little visual confirmation or haptic feel of longitudinal weight transfer:

I've now had a 10 day break from AMS2 and have only driven other racing sims in the meantime (mostly iRacing, AC, R3E). Getting back to AMS2 again, I now understand where this claim is coming from. Cars in AMS2 typically don't dive/squat that much, and in many of the cars there is no sense of the FFB getting heavier when weight is transferred to the front or lighter when weight is transferred to the rear. In the few cars that have a little bit of that effect, the weight transfer response felt in the FFB arrives a bit later than expected (as if delayed through tires/suspension). And if I brake so hard that the front tires are overloaded, the scrub effect in the FFB replaces any feel of weight transfer. I can see how this makes the onboarding process difficult for players who come from other sims and have trouble getting the feel for how cars drive in AMS2.

Thankfully, I think there is one good exception and a few other minor exceptions. In descending order, here are the cars that I think have the best feel of longitudinal weight transfer in AMS2:

1. Formula Dirt when driven on dry asphalt
2. other cars in the Adrenaline Pack (but the FFB isn't as good as F-Dirt, even if the visual suspension travel is greater)
3. Vintage TC Corvette C3, although the feeling is a bit delayed
4. F-Vintage G1M1, the feeling is not so much delayed as above, but requires smooth inputs
5. Formula Vee and a bunch of other vintage cars, when using custom FFB profile

An interesting side note: Ever since the 1970s with the Lotus 72, many Formula 1 cars have had anti-dive and anti-squat suspension. Therefore, with the recent addition of various 2000s F1 cars to AMS2, these cars are probably the least likely candidate for players to feel longitudinal weight transfer. This could be one reason why this specific discussion has surfaced recently.

I invite anyone who struggles with feeling weight transfer in AMS2 to try the following combo and report back if the weight transfer feels better/worse/same as other AMS2 cars:

• Formula Dirt @ Córdoba No. 2, dry conditions
• Default+ or Default FFB profile (For some reason, custom FFB profiles feel worse with this car)
• Tip: To avoid overloading the front tires when braking, try reducing front brake bias and/or reducing brake pressure (either by applying less physical pressure on your pedal or by tweaking the brake pressure in the setup)

Do you agree with me that the Formula Dirt feeling of weight transfer is noticeably different from other AMS2 cars? Especially the Formula Vee which is pretty much the same engine and chassis, yet feels so different to me. If so, what could be the reason? Is it just down to the tires? Something in the suspension, e.g. pneumatic trail?

To be clear on my intentions: I'm not saying "this or that driving feel is more realistic", but my point here is to investigate if there are ways in which we can make the new player onboarding process from other sims more approachable. Also, I'm using this as an opportunity to shamelessly promote the Formula Dirt which in its current iteration (1.6.9.91 build 3398) is one of the most fun cars to race in AMS2 on small twisty tracks, in my opinion.

Catching up on some comments:

I believe I found the exact quote below, so that we don't have to paraphrase and potentially quote him wrong:

Source: Automobilista 2 V1.6, IMSA Track Pack, Endurance Pt2 & Lamborghini DLCs RELEASED (V1.6.3.6 Live Now)
A later reiteration of the same/similar point, worded differently:

Source: Automobilista 2 V1.6.7 RELEASED - Now Updated to V1.6.7.2

I too find that it seems easier to modulate the amount of rotation with weight transfer in AMS2 than in other sims, but with one caveat: Only when working within the limits of the car, i.e. when the tires are "happy". When the tires are overloaded, that's when AMS2 really starts to feel different than other sims. The Superkart is a perfect example of this: If I use smooth throttle/brake modulation through a corner, I can control the rotation as much as I need to, without altering steering angle. But other players have reported that the Superkart is an understeer machine, so clearly we're doing something different. I'm thinking that they're not getting the feedback they expect and as a result, overdriving it and inducing understeer.

This leads me to the following hypothesis:

1. Players coming from other racing sims
2. On corner entry, these players expect:
   1. FFB to get heavier as weight shifts to front wheels
   2. The FFB getting heavier in tandem with the weight shifting forward should indicate that front tires "hook up"
   3. (in contrast, lighter FFB should indicate understeer due to overloaded fronts)
   4. Then, use trail-braking to bring the weight balance back on all 4 wheels, felt through a reduction of the heavy FFB into a more neutral/balanced feel. If the timing is correct, this should achieve optimal slip angle
   5. If the car has over-rotation on corner entry, this can be felt with a sudden heavy snap in the FFB and can in some situations be saved if the player reacts quickly enough with a counter-steer, effectively "balancing on the limit of maximum grip" as the myth goes.
3. When AMS2 does not provide this expected feedback through the FFB, players think that they need to unsettle the car more in order to get it to turn in better and finally get the front tires to "hook up". Additionally, the general trend with AMS2 default setups is to have stiff front suspension/tires and soft rears, which adds further evidence that changes needs to be made for the car to hook up better.
4. Players then use exaggerated inputs and/or setup workarounds that used to be valid for older versions of AMS2 (back when AMS2 had problems with locking diffs, etc.) When this also doesn't work as desired, existing beliefs are further entrenched, and the same stuff is tried even harder.
5. Exaggerated inputs, overdriving, and weird setups cause unstable corner entry, so trail-braking no longer has its desired effect because the car is already unstable. Additionally, when this overdriving leads to losing control of the rear, it happens quite suddenly without warning.

Am I on to something here?

 

I don’t really have anything that I would disagree with those points. You feel more of the weight transfer with rear going light during braking instead front getting loaded and in other sims it’s often opposite. During acceleration, you don’t usually have the understeer, but can get lively rear that can feel slidy especially compared to other sims, where you get that understeer a lot more easier when you get to throttle or sudden snappy oversteer with more powerful cars (especially with low TC)

Even though I prefer AMS2, I’m not fully convinced in those things mentioned, but the same I could say of other sims, but from reverse perspective. I find AMS2 a lot more fun to drive though.

I also don’t think the game punishes enough from sliding and abusing the tires in a way you probably wouldn’t want to do irl.

EDIT the cars do dive / squat, that is visible from telemetry just from looking at ride heights on those moments. I guess the question is does it happen fast enough, is there enough of it, how much it impacts the grip levels and so on.

 

I know for a certainty that the original Assetto Corsa had unrealistic, exaggerated weight transfer and dip and roll.

I still maintain that it is far more important for AMS2 to attempt to mimic real life, not other sims. And that should be the benchmark for every game. I understand that FFB etc., may need to take some liberties to try to convey the feelings of a car being raced, but I think there needs to be a good balance of how artificial those boundaries are stretched.

If people don't like it, they can play something else

 

AC and rFactor/rF2 based sims have been good enough to be used as basis for pro versions, so the it’s not like the core would be completely wrong either.

I’m not a irl race driver, so I don’t know much how things like this should impact on average or for specific car, but nevertheless, i don’t feel that either end of the spectrum is clearly more correct. In ams2, you notice the weight transfer mostly from rear going light under braking, especially after you have slowed down and are using the brake and lot less fronts loading or rolling. I do find those tendencies excessive the same way I feel the understeer tendencies or rear being on rails is excessive in other sims.