To Reiza: What physics do you actually want?

This is more an open letter to the reiza staff than anything else.

Let me start by saying that i have no meat on any other game. My most played by far is AMS1, for which i have spent years modding. Also, i have been one of the very few advocates of the madness engine around various simracing forums/outlets. So no need to fantasize about me being here to try to put it down for no reason.

Also, i dont not intend to start a debate about what is realistic or not. This is my opinion only.


And i start this with the question of the title. What do you want the physics to be like? Are you trying to emulate AMS1? Are you trying to do something else, and if so, how do you want the cars to feel/behave?

I ask this, because the physics and car behaviour have been all over the shop since this game came out. At some points i thought it was going in one direction, to imediatly go into another in the next update.


I guess this needs proper explanations so let me get technical.

So to me, it seems that you maybe want the cars to feel somewhat like they did in AMS1, very "light", with very grippy tires, that snap suddenly from under you. Except now, at the same time, they regain grip incredibly quick, and can get to such huge slides that its possible to go sideways around indianapolis at insane speeds.

Now, i know this is a fault that was reported, but the problem is not the glaring things, it's the little ones.

If we drive the lotus 98T in Pcars2, with VINTAGE/HISTORIC tires (this is important) , i have a car that is informative, has wheelspin that is controlable (wheelspin, not sideways slides), and is also pointy and responds quick to the steering with the front, while at the same time transmiting a good sense of weight and inertia.

If i drive the equivalent in AMS2, i have a car that instead of having progressive wheelspin, snaps the rear whenever you touch the throttle, forcing you to back off all the time, or worse, learning by MEMORY when to accelerate and by how much, only to arrive at a corner, and have the front plow like if you have worn tires at the front.

Getting even more technical, it seems the car has incredibly gripy rear tires or incredibly tight rear slip angles whenever the car is coast/braking, to being totally overwhelmed LATERALY (important) when you go back on the throttle, together with such incredible lack of dampening somewhere (can be inertia, dampers, or even tire sidewalls) that the car just jerks sideways on top of it's own springs all the time in some sort of tankslap around itself. This later trait is worse in some other cars, like the group Cs.

Notice that i am not talking FFB here. I am talking what you can even see from the outside. If you watch a replay of yourself driving the car in PCars2, and then the same in AMS2, the first looks natural and makes sense, the second shows a car twitching all the time and behaving erratically whenever the inputs dont please it.

Now this leaves me speechless because if anything, instead of using the good things that were on the Pcars series and the madness engine, you are basically devolving the physics to feel like the worst traits of stuff made for rfactor1.

Then it seems you want to overcompensate this with amazingly compliance and forgiveness at high slip angles, hence the dirt tracking at Indy.

I tried to speculate that this might be to appease controller users, but they have been vocal that the game is not good on a controller either, so i am left with more questions than answers at this point.

I could complain about more things, like unresponsive setup changes, things that make little sense in some individual cars, but honestly, why bother, when for me the fundamental is making no sense at all to begin with.

And yes, the odd car can feel ok depending on what fix we are on, and when the moons align,but it became increasingly clear to me that the physics people/person seems lost and directionless and this happens more by chance rather than design.

Another perfect example is also the formula retros. This car was never good in AMS1. IT should be almost a drift machine if you look at real footage, and in AMS1 it was stiff and understeery, and now in AMS2, despite all the possibilities of the madness engine and the SETA tire model, its even worse?...

I know this is being an overly negative post, but myself, like others are totally puzzled, and some even mortally disappointed.

I know and i read that the team believes that tires should be more compliant than in other games, and probably than the content the same team created for AMS1, but i dont think (or rather hope) this means dirt tracking around indy, but instead, making a car like i described the lotus in pcars2 to be, compliant, informative, and with handling that makes sense, both in the cockpit, as well as viewing from the outside.

Anyways, please dont take this the wrong way, i am not putting down work just for the sake of it, i know how that feels too well, i am just venting my purely personal reasons behind why AMS2 feels so underwhelming now. I am glad the game is getting more atention , even positive one lately.

 

I think I more or less agree with you about this car.
Since this car was launched I have solely been driving this car up on some of the TT LBs.
Im good and fast but like you Im beginning to think that there is something wrong or at least strange with the extremely snappy behaviour as soon as you put the throttle down.
Hehe or even worse if you put the throttle down and the turbo switch kicks in.

ByTheWay: I still try to take this snappy behaviour as a challenge - but if this car was behaving this uber-brutal way in RL then all the drivers of it would have been killed after one or two races.

 

I just asked about this throttle behavior. Even in the street cars i feel like im driving an old car with a huge turbo. In real life the throttle is very linear and controllable in newer cars.

 

A lot of cars have this behaviour in AMS2, even cars with open diffs like the 1999 Stock Car or low HP low torque like the BMW 2002 before the turbo kicks in, that IMO should have no business sliding the rear out that much on throttle, instead they should probably spin up the inner rear tire or just stick and accelerate normally.

Edit: Pertaining to the bolded part above, I was wrong: The rear of the BMW does indeed only kick out once the turbo engages, even at just half a bar (if the information for external dashboards is correct), but not before. Basically the rear tires of this car get overwhelmed as soon as the turbo starts producing power. This can be migitated to some degree by significantly increasing preload.

 

This game is still very dependant on diff settings, defaults being too locked out of the box does not help. And while my experience does not feel as dramatic as what Richard explained opening this thread, I will agree with him that the physics seem to be shifting away from what they were between versions 1.3 and 1.4, but I thought it was simply defaults not being good enough and myself not putting enough work on setups. But if the latter does not solve it, then maybe something is going on. It could be part of a transition process while Reiza tries to unravel more things of this engine, I would like to believe.

 

I have just gotten myself a DD wheel and believe me or not, spending now more time on revisiting cars in PC2 than in AMS2 because of the behavior you have detailed
where I would love to do the other way around now considering how deep and rich in content variety is the Reiza Game

 

Diff settings usually help, even with the aforementioned BMW 2002. If you drastically change the preload, the car becomes very tame. The 1999 Stock Car however has no diff settings to change IIRC.

I remember a discussion at the beginning of AMS2 development, where the question was asked how much of any odd car behaviour was underlying physics issues, how much was bad stock setups, how much is just car characteristics and to differentiate the three. For example, does the 1999 Stock Car just have a very slidey rear and wonky weigh distribution that make it behave how it does, or is there an issue with the car, or is there an issue in the physics, or is it a weird stock setup? It is quite powerful and there seems to be little weight on the rear axle. Do setup changes make a car suit somebody's driving style better, or does it compensate for a flaw in the programming?

IMO it's not that clear cut, and I'm no knowldgeable enough to answer that, I just know to open up the diff a lot to make the cars behave "more believably". The problem comes with cars that have an open diff or low power, if they still slide when barley touching the throttle. Maybe the issue is with throttle maps.

 

I agree that sometimes grip loss in AMS2 feels too abrupt (yet controllable unlike in ISIMotor titles), although there's no clear trend as I also find that most of the GrC cars are very snappy (especially under braking where it's very easy to suddenly flop sideways), but the 962 is almost perfection.

Many old school sims exaggerated the ease of spinning under power so that if you put 5% too much throttle in 2nd gear you instantly did a 360. But if you look at footage from old F1 races of the 80s and 90s, most of the unforced spins seem to come on corner entry and you rarely see anyone doing a sBinnala on corner exit. The cars do squirm plenty on corner exit, but even the less talented journeyman drivers seemed fully able to control the wheel spin and do 45-degree burnouts when leaving the pit box in a manner that, if reproduced in any ISIMotor title, would lead to half a dozen dead pit crew members.

I don't agree with this characterisation of the F-Retros. Just by looking at their design one can deduce how those cars must have behaved. They had huge slick rear tyres to reduce the lack of grip under traction that the F-Vintages suffered from. Concurrently, to reduce drag and lift in the front (that created massive understeer in fast corners), the front tyres were made too small compared to the rear tyres, causing the fundamentally understeery characteristic in tight corners.

Then there was the airbox designed to provide cleaner air to the engine that totally disrupted the airflow and reduced rear wing efficiency. This lead to catastrophic snap oversteer at high speeds, which had to be compensated for by moving the aero balance towards the rear. At the same time, Brabham with the BT44 started experimenting with underbody aero, leading to running a fairly stiff suspension setup.

All these aspects combined to mean that these types of cars are almost universally understeery in any reasonable sim representation. Of course they used the bias ply tyres' more permissive slip angles to cheat a bit and overdrive into the corners, just like Jim Clark did back in the day, but if these cars behaved "almost like drift cars", something would be dramatically wrong with the physics.

 

Yeah there are definetely issues, who knows how much of it is down to however many factors like wonky setups or engine quirks but I reckon work'll be done to polish things out in due time since the core physics are supposedly in their "good enough" state
Sidenote: you worked on the ISO cars, right? From what I remember, the big tire, grippy open wheelers that handled "almost like drift cars" was a trait that was somewhat characteristic of those mods (They were fun to drive though, I won't deny) so it's interesting hearing your take on the F-Retros

 

I dont see how that is any improvement over the "ISI gmotor physics" you describe (which could be dialed out by the way). If anything, it makes AMS2 look even worse, because it means you can still catch an impossible situation.

As for the 70s F1s, if they are setup up for understeer, then they are almost a drift machine by default. Yet, if you try to even kick the rear out , you will be rewarded with tankslaps and unruly behaviour imediatly, instead of smooth throttle controlled slides.

 

I am the one that does the ISO physics yes.

 

Some thing I can say, that I'm confident is 100% correlated, on the shared memory, the wheel_slip value outputs higher values than other games from start and to make transducers work well I have to set the gain at ~30% value, with some threshold adjusted by try and error.

I'm have also observed that the slip sound is near at 100% just start having a tiny little slip (feeling from the transducers).

Something wrong are happening here, i don't know if is from physics side, because what I feel is the real slippery effect. You have to be very careful with weight distribution and throttle (obviously), but the part that i feel different from others sims is that the wheels don't have the capacity to get and feel traction grip instead of lateral slip (sorry for my bad English and explanations, Idk if these are the correct words to explain what I feel and see).

Also, I have triples, so plus for the perception of the 3D space and the behaviour of the car.

 

Sorry I have reconsidered my oppinion about this car.
I would be VERY sorry if this uber-brutal car was made tamer and therefore less challenging.
Because as it is now it does really separate boys from men.
Yeah this is partly a joke - but when you are able to master this car on a certain track then you know you are something special.
Because deep inside you know that all the funny goofy casual "boy" drivers who does moan all the time that their time is too important to be used to setting a car up - will never be able to master this car.
Even if they have luck to "steal" your personal custom setup from the TT LBs.

The reason I have come to this conclusion is because I have just up´ed one of my top laptimes on one of the SPA Historic tracks.
And I was so sweaty that I had to wash my armpits afterwards.
But it was so extremely satisfying

ByTheWay: So PLEASE Reiza dont touch this testosterone car.
Because eventhough it is maybe(!) slightly more brutal than it was in RL - then no other racing sim has such a car bomb.
Eventhough AC comes near.

 

This is one area that needs improvement in my opinion, the setups. Most cars start with around 100Nm of preload in the diff which makes them drive like a snow plow and then it is further compounded by default setups that have front ARB values of 14-17 with rear ARB values of 6-10. Reiza has mentioned they want the cars to be controllable by default, but this seems excessive and I think makes it hard to understand what is going on until you make some serious time investment in the setup process. Maybe this is needed to appeal to the controller crowd, I don't know.

 

I know this is not what you ask for but you can more or less solve or sidestep this throttle response linearity problem by playing a bit with the throttle "sensitivity" in the controller settings.
A sensitivity under 50 makes the response "softer" at the beginning of the throttle movement with a "steaper" in the end.
Over 50 is the opposite.
I use this myself to get better control.

 

Thats not going to fix what im talking about. Down low is fine its part throttle and above where you go from nothing to blowing the tires off. Plus i dont want to band aid the cars then the cars that do drive right will be weird.

 

See for my IRL car (2017 Focus RS) the throttle is not linear at all and I have three different throttle maps with the stock tune or the aftermarket tune I'm using. Sure there is one that's a little more linear in normal mode but it's still not linear. The way Ford has setup the throttle in the RS is very punchy at the beginning and leveling off a whole lot towards the end of the pedal.

So I get pretty much 100% throttle at like 75% pedal.

And to add to above my last IRL car (2011 STi) was also not linear at all. I think it was very close to how Ford has done it in the RS or even less linear.

 

Right but you changed that. Most throttle by wire cars are laggy down low on purpose to make them easier to drive plus you have torque management built into most stock pcms. Thats the whole purpose of a Pedal Commander they sell. That still wouldnt make them behave like the cars in the game. As a side note i have a 500 plus hp 6.0ls in my 87 Blazer with 4.56 rear end gears and it doesnt drive anything like the cars in the game. Either do any of the other ls swapped cars ive done. Even at 500hp they are super easy to drive and totally controllable. Sure you can be stupid and blow the tires off but they arent hard to drive especially once your moving.

 

I'm not trying to compare to things in the game as I was just referencing the IRL car throttle.

Also no it's not because I changed it. From Ford and from Subaru on the stock tune the throttles are not linear. You can look that up if you like. They are not meant to be linear so the cars feel faster.

 

I think this has become more of an issue in the latest patch (1.4.5.2), after the tweaks to street tires. It's extremely easy to spin out on throttle inputs, and at the same time the cars have become more understeery in light throttle situations. It's getting more and more difficult to control them.
I had a tough time dialing in the diff on my mod 992 street car whereas it was very controllable on tires in game version 1.4.3.*
Of course I test with vanilla cars as well, but it's the same story there. Even worse, actually. Ultima street was becoming manageable in 1.4.3.*, but now it's not any more.