Physics discussion thread

I see, so does that mean he has had a promotion or demotion, lol

 

Not having to deal with the riffraff like us on the forums seems like a major promotion.

 

Here are the correct gear ratios for some of the cars that have them simulated wrong in the game

Audi R8 GT4
Audi Uk

Aston GT4


Merc-AMG GT3


Porsche GT3 R 991


Porsche GT3 R 992


BMW GT3

 

Are those gear ratios the same between IMSA, WEC and GT Challenge?

 

(And Império Endurance Brasil.)

 

Something that’s been bothering me for a while is the sensitivity of the gas pedal you simply can’t accelerate smoothly at all especialy in the JCW and I tried all the sensitivity settings, but they didn’t make much of a difference. So I tried ACC in a GT4 class car—no problem with accelerating—then tried AMS2 again, also in the same GT4 class car. And once again, the gas pedal on/off switch—the handling in GT4 in AMS2 is still like an ice rink with way too little grip. For now, I’m giving AMS2 a rest until I read somewhere that this handling issue has been resolved, and especially the gas pedal on/off switch.

 

Have you seen this video?
If not, it has an excellent explanation on real throttle behavior and how AMS 1 (and 2 I think) are about the only sims that get it right.

In short. You only need a little bit of throttle to get most of the torque. In most sims you need to smash the throttle pedal to get the car moving, but that is just not realistic

 

Yes I known that video, but the on/off switch throttle is annoying and I have this strange throttle behavior only with AMS2, Not in AMS1 or AC or ACC or raceroom.

 

Reason to this might also be that ACC simulates throttle response curves with ECU settings. Setting 1 often is linear while settings 2-4 are non-linear. Just like in any modern car with different drive modes, where throttle and power steering sensitivity, ABS and TC setting change a lot ranging from ECO to Track setting.

The problem with GT4 class in AMS2 might have another reason, since the class still suffers a lot from that old excessive throttle oversteer issue that plagued the GT3 class for a long time (and still does, to a lesser extend).

 

It's odd that you write that AMS2 behaves differently from AMS1 in this regard, since they should be more or less the same when it comes to the throttle response curve, and to me they feel like they behave in the same manner. So maybe what you're referring to is something else, maybe related to driver aids (Traction Control, etc.)

 

Exactly this is what the problem is with the GT3 and 4 class, TC and ABS react not realistic as it should be.

 

Tbf this problem persists across all the vehicles with driver aids built in. It would be a massive undertaking and honestly unviable to accurately model the TC and ABS in each car as there's stuff from the 90s, 2000s, supercars, hypercars, gt cars and so many more with different TC and ABS systems.

The classes which very heavily rely on these systems to even stay on the road should be the ones getting accurately recreated in my opinion. Although then there's the argument that, one doesn't usually fire up automobilista 2 to race GT3s around Spa and rather a lotus 79 around classic adelaide so would it even be worth it at all when the current system is just about passable.

 

With the update I think TCS became much better. Not perfect, but really better. The default value of 6 is just very high, it will intervene really hard to make the car safe. For dry conditions you can go for TCS 1-2 with strength at low and you can drive many corners with very few TCS applications without the car going to slide. It feels great that if you encounter slip then you actually have quite the risk of flying off if you're pushing too hard. Especially the last corner of Sebring now requires way smoother input to get through it fast and safe

I would love to see a separation between allowed slip angle and wheel spin though, it feels like it's overly sensitive to slip angle even with no wheel spin happening

 

It could be beneficial if the devs were able to design say, 3-5 different implementations each of ABS and TC and each class could be given the one closest to authentic; at least as a placeholder until a bespoke system were (if ever) designed.

It may be more complex than that though, depending on how those effects are built in to the engine. I don't want to speculate on how the effects are coded.

I very rarely drive cars with TC and ABS though, so I can't comment on their realism of implementation.

 

I tested out a couple of the cars with the updated physics and noticed that the diff is behaving differently now. When i was using pre 1.6.9.5 setups, the cars felt twitchy in the traction zones and it was quite noticeable that the outside wheel was getting too much torque. I know for sure that i set up the diff to maximise traction, at the time i made the setups, so it's clear that there have been changes in this area. When i reduced the preload, the cars always became more managable in the traction zones.
So if you are using older setups, you might have to reduce the locking of the LSD (either clutch plates or preload), especially if the car feels twitchy or difficult on throttle, in order to make it work with the current version.

 

Had a dry to wet race in the Mercedes GT4 last night and I gotta say slicks on a damp track now feel way better than they used to. It's slippery but not in that old overly exaggerated way it used to feel, more controllable right up until the track gets too wet, then it's aquaplaning for days. I still feel like puddles could be a bit more dangerous, I was running over them pretty consistently and didn't really suffer any slips.
The rubbered line also feels awful in the wet, which is exactly the way it should feel, so A+ on that front too

Overall, whatever physics updates happened to the slick shod cars is a big plus, you've done a great job!

In my opinion there's still a bit too much of that feeling of getting on top of the tyres and floating the car through corners in the dry. It feels like the front end is slightly too effective on initial turn-in and it yanks the rear around behind it. Right up until you pass the limit and understeer off into the weeds. But it's not a deal breaker, just a characteristic of the sim.

Enjoying the update a tonne!

 

I personally don't find the high downforce cars to feel "floaty" anymore. Sure, there's probably still some slower class cars that still feel looser than they should be. But I think the new slick tyre adjustments have helped with that. I'm looking forward to seeing what other improvements will come with the 1.7 physics update.

 

Try AMS1 and than go back to AMS2 and tell your experience about slippery and floating cars between those sims. My experience with AMS2 is that the cars are slippery and floating in compare to AMS1 where you feel exactly the limits and the natural feeling to correct oversteer. I hope some day Reiza will manage this issue with AMS2, for now I went back to AMS1

 

It's not that extreme really, imo. The cars in AMS2 certainly can feel a little looser, but nowhere near as much as they used to. They're far more direct nowadays, I think it's really when pushing the limits of grip that things can feel a little off.

Something to try with the setup is turn the number of differential clutches down to 4, and/or reduce the preload. It's counter intuitive because it'll loosen the diff up slightly, but it'll make it act less aggressively when it locks, which is what can sometimes give that vague feeling at the rear.

Edit: Also that tyre scrubbing noise can give a false feeling that the tyres are slipping when they're not. You feel a lot more of the elasticity of the tyres than maybe you would in other sims (which is a good thing, imo), but that overzealous scrubbing noise really needs to be changed.

 

I don't quite get how can throw the whole game or even a whole class with many different cars into one merged judgement how "AMS2 feels".

Let's look at a few GT4s, these all behave really differently:

• BMW: Very loose rearend on corner entry and corner exit, this cars base setup indeed is quite loose
• AMG: This car is way smoother to handle and feels well balanced. It's way more on the understeering side and you really need to work with trailbraking to get around corners fast
• AM: Sits right between BWM and AMG, it can step it's rear out on entry but understeer on exit
• R8: Very precise and balanced turn in, slight understeer on exit but be aware of snap oversteer.

But here's the catch. I think this is actually how it should be. I was first wondering if the M4s behaviour makes sense for a frontengine car, this oversteering setup is quite aggressive. But then I looked up footage like this and you can easily see how this car indeed had much more oversteering on the limit (have in mind the one ingame is not the current M4 GT4 Evo but the older one)

Compare that to how - similiar as in AMS2 - the AMG GT4 seems much better balanced and more on the understeering side

Also you still have to option to modify bevahiour with the setup, for the BMW i just increased front ARB and decreased rear ARB one click to give it more frontend grip on corner entry and more rearend grip on exit and it felt so much smoother.

If you still find some very planted cars like Formula Edge Model 3, AMG GT4 or M4 GT3 very slidy I honestly think there is something really wrong with your settings or FFB.

So to keep this discussion much more insightful and helpful for Reiza, I think we should always make sure to be clear which car we are talking about and how exactly it behaves different than expected. In the best case even record clips where cars have issues. Renato stated in the patchnotes that these are the initial revisions for 1.7 so there's still time to actually deliver good feedback which cars could improve.