Physics discussion thread

When I look elsewhere, I see people parrotting those "physics are off" claims, but hardly ever going to detail on what way and providing solid arguments and proof. Then those claims would actually be useful. A lot of them are also based on very little personal experience in both game or IRL.

As for IRL drivers, there are very few known names that I have read and made reviews of AMS2 (sim/irl racers like Baldwin, Broadbent, Jardier... who else?). Please provide more? As far as I know, Morad or Perel hasn't yet made a video / review of AMS2 at least. Because the game doesn't have any profilic MP competion scene (and physics definitely hasn't been main reason for that, the MP functionality wasn't even close to being solid enough for it in the past), so it doesn't interest that many as much as the other, bigger titles.

This is not a defence of AMS2 physics, it's annoying as hell to refer to read those claims that doesn't have any substance.

As for other sims feeling similar, ACC and LMU for sure doesn't feel similar with the GT3. Other sims definitely don't have perfect physics either, ACC with it's suspension implementation is a good example of that (and braking). Both of those games have plenty of weird things going on with how you can and should set the setup for optimal performance, which to me always mean that the simulation isn't perfect there either. For sure, AMS2 haven't had all things correct, still doesn't and never will, just like every other sim, but probably because some of the bigger problems in the past (originating from project cars), it got famous having "imperfect physics" and that stick to this day (unlike other sims), no matter how much those have improved.

1.6.8 improvement with the GT3's was clear, it definitely removed the rear coming too lose easily on corner entry, especially if trail braking deeper into the corner and reduced the on throttle rotation tendencies a bit. I did back to back comparison testing with this during beta phase between previous public release, so it wasn't placebo. For those whom these issues were the main problem, the change was really significant, but if you had some other issues with the simulation, it's understandable that such person might not feel that way.

I do see imperfections with the GT3's and how driving them feel in AMS2, not feeling heavy as if there wouldn't be enough forces pushing the whole car in corners, tires not being peaky with grip dropoff, maybe having too much downforce in the rear etc. But in similar way, I feel imperfections in all the other sims I have tried GT3's as well, just different kind.

 

You're reading a bit too much into my post I think. I'm not a fanboy and I wouldn't defend any point I don't like about a game just because. I also spend my time in other sims, and not in AMS2 only.

If you check my post history I think 1.6.5 already updated GT3s so much, that I couldn't find that much difference to LMU especially on cars like the M4 GT3. 1.6.7 was the biggest step since then with the adjustment of rear aero loss on yaw rotation. Jumping between LMU und AMS2 GT3s is to me as close to each other as any other sim.

With 1.6.8 I even ran into the issue that I couldn't drive GT3s anymore since they constantly understeered, until I switched back to Default FFB and that solved all the issues. So I'm totally open to talk about issues when I encounter them.

So with that being said, I actually just want to help solve issues of people still saying they feel the cars slide since I absolutely can't feel or see that in my rig. But for this we need to dig deeper than just the typical "it's still slidy" post, that can't show any gameplay clip that showcases where the slip happens so other could recreate the issue and test if the same things happens to them. Especially since n off FFB can easily give wrong impressions of how much grip a car has (and I even had this issue with Custom FFB in 1.6.8). Or even better capture telemetry like Peter Stefani does here to point out anomalies.

 

Aren’t the bump stops only on compression? The issue on the RSR is during Extention of the suspension upwards upon braking.

Almost as if the top of springs are not attached to the body of the car, as a manner of speaking. Probably would be impossible in practice, but in the end this is just a simulation, not real hardware. I guess anything can happen when it’s all just code and formulas.
And if you look at some other cars where you can visually see the rear suspension in action, you don’t see this extreme Extentions, and it doesn’t appear as anything odd in the MoTeC readings either.
You can see the rear suspension moving up on braking, but not to the point where it just flat lines and sits there.
I really should look at that other Porsche that is similar, and how it responds under braking. Then report back about it.

 

This would be useful to remember for all of us here. Errors can be overlooked when things seem fine on the surface or during test drives.

I think there is clearly enough evidence here that Reiza should investigate the issue (telemetry error only or a modelling error leading to telemetry wonkiness) with this car. Just in case they are not paying attention (due to busy release schedule and dealing with all sorts of issues with new stuff), I will add it to their list The car is way too much fun to drive now to leave it with an unaddressed problem.

 

I drove the car and agree with you that there's something wrong with the bump stops. And this is just my opinion, but I think this car should understeer more when braking.

 

Yeah we tried with full bump stops and no bump stops, did not make any noticeable differences. And to be clear, the issue is NOT about the bump stops.
If the investigation gets done, it would likely result in an increase in the spring ranges.
I’ll be checking the other Porsche later today to see what is modeled in that car and how it performs.

 

For me when it comes to GT3, LMU is my favourite

Yea the likes of LMU do them better, where they require precision and you have to be more careful as it’s much easier to make a mistake.
Where’s in ams2 the slidy behaviour is mostly gone, but you can be much more aggressive and less precise in your inputs.
It’s as though you have way more grip and downforce, but for me they feel much improved than earlier and now at least fun to drive, but ultimately it would be nice to have to require more precision, and balance in inputs overall and bring them closer to other sims.

but overall it’s now getting to a state where if the career mode is really good, I will put some serious time into AMS 2.

 

Never

 

You have to be very precise when you want to be fast. If you overdrive the car you will lose a lot of time. The big difference is that you don't lose the car to uncatchable snap oversteer when overdriving the car or randomly in certain corners, so you aren't enforced to underdrive the car all the time when pushing them to the limit.

As showcased in other posts with tons of IMSA clips, IMSA GT3s are quite loose on the rear when driven hard and don't spin out instantly when rear grip is fading. I get that people are used to this underdriving approach and like it, but I honestly hope AMS2 does not take that as a target.

 

The other 911 Cup cars 3.8 and 4.0 (even though different from the 1974 RSR) didn't show anything odd and drove well.
One thing we noticed was that the 74 RSR had quite a bit higher ride height values than the other Cup cars, GT3, and GTE.