Cars VRC American Racing Championship

[Dirk Steffen]

... just a few small points I saw when racing some more with the Chevrette:

- AI does indeed like to flip the car over curbs (Sears Point, Mid Ohio)
- in lower LODs the under body of the car becomes transparent so that cars that flip further ahead of you become partly transparent when they flip through the air (needs a simple black, non transparent under body in lower LODs)
- there are some Z-fighting texture issues with the rear light cluster - I could not determine which LOD is involved as I only saw this happening quite badly on all AI cars when racing behind them
- instrument faces have indeed a little too much AO plied to them (mentioned earlier by another poster)
- it would be really nice to have some "dirty", "scratched", "worn" cockpit textures a la RSS mods in this car, seeing especially as these cars were always a little "home made" - for lack of a better word ;-) Murrica and all
- rear view mirror vantage point could need some adjusting - the rear view mirror position unfortunately does not line up with the mirror window cut into the rear fire wall when using the CSP real mirror plugin (mirror vantage point in car.ini (MIRROR_POSITION) ) currently that big, fat surfboard mirror does not much ;-)

These are really only small details but it would be really nice if these could be adjusted once you find time for it.

I love the sound of these by the way (apart from the water mark jingle).
These are a hoot on all american tracks with proper IMSA GTO fields - I wish we had more of the original tracks with larger grid numbers as most availabel have only ~24 - 28 grid slots)..

 

[gecco]

I've been in touch with the devs on their support forum, and also have the impression, that they seriously did weigh in the pros and cons of the available options, before deciding to go with the DWB and try to replicate the cars handling that way. Also, they are considering to implement a live axle for a future update.

Well, the sound file. Yes it's there, but as soon as you hit the drive button, it stops.
Of course, this being a paid mod, I was kind of not expecting that either, but again there are reasons for the audio file as it is, and the devs cared enough to explain to me.

Living under a rock..., I only yesterday learned that VRC are seemingly working on the not IMSA Audi 90 already!

 

[IMrIMike]

Two critical points
I do have though regarding the mod although overall I am really happy using it:
1) please pretty please remove the sound loop on all new VRC mods "This sound is created by Mr. Mike for ..." It is very annoying and it does actually interfere with game play in AC as every single time when changing to a VRC car in game this loop is played (not just on session entering)

First off, thank you for your extensive input and feedback, much appreciated.
Unfortunately removing the watermark will not be an option for me, for reasons I've stated (especially here on RD) multiple times. That doesn't mean I'm not looking for a more subtle solution, as I can understand this may be annoying at some point. However, this car being really the first one with multiple reports on that matter, I assumed most people would be okay with it, since I've included this message into my sounds for over two years now. I've already shortened the message by a fair amount, but like I said, maybe there's a more subtle solution that provides the same watermark effect.

It´s interesting you mention a loop, as this shouldn't be the case. The way I have it set up it should be played once and once only, on startup that is. Let me look into that again.

 

[arixant]

having way too much fun whipping this thing around, had to start making an accurate version of the skoal livery.

also i dont know if its been asked if theres a way to paint on the windshield banner, id totally love to know.

 

[Qazdar Karim]

I'm out of my technical depth here and heavily reliant on the expertise of others, but because of that fact and because it's a pay mod it would have been nice if you'd made this clearer. The car is lots of fun to drive and I'm sure that's the whole story for some people. But a big part of my personal enjoyment is simulation of real life racing cars not fictional ones. I hope you consider revising the physics if you get the chance.

Thanks for the feedback!
Yes, I will change that for a future update. (for 1.2 most likely since I will have to rework a lot of things)

 

[SunBro]

Thank god we won't have this conversation all over again with the audi.

DWBs for daysssssssssssssssss.

 

[AccAkut]

just skimming the thread, but @Dirk Steffen, AC totally does allow for anti squat/anti dive, some forms of true Multilink etc, just needs "maths" applied. Biggest issue with it is finding source materials.

 

[mclarenf1papa]

I think the discussion of what suspension geometry physics constraints have been used in a mod really should either stay off the table here or should be explained at full transparency of the mod maker as to completely prevent any misunderstandings.

The matter of the fact is that unfortunately the Kunos AC live axle suspension definition is highly limited and really unsuitable to be used in fairly modern race cars (that in real live had a live axle rear end).

The reason for this is that unfortunately the Kunos definition in AC does not allow for any simulation of camber and toe changes while also advanced systems as anti squat are not possible to be simulated as used in modern racing applications.

For this very reason a specific reason the Kunos AC DWB definition is a popular (and currently best use) option to work around the highly limited live axle definition in AC.
With such a specific DWB definition many behaviors of the real life cars rear suspension can be much better simulated.

It is a compromise - a workaround - a trade off and the mod makers surely have weighted the decisions of what is more important with the specific car here.

Personally I agree that on what is essentially a prototype race car of the late 80's features such as adjustable camber and toe indeed are WAYYY more important to simulate the actual cars behavior than the unfortunate loss of the real cars live axle cornering behaviors (yes, we loose those).
It is a trade off.

Without having looked detailed into telemetry data but from having spent perhaps only an hour racing teh car with a full IMSA GTO field at Mid Ohio and Riverside I can say I like the behavior - it is plausible.

From having checked past VRC mods regarding suspension geometry vs telemetry data I can say that decisions in suspension geometry design I could see sound reasoning and well made decisions.


What people who do not build car physics in Assetto Corsa do often misunderstand is that very often with exotic suspension systems (such as true multi link, semi trailing arm, live axle, etc ...) a workaround compromise using the DWB physics system is unfortunately the only tool we have in such cases.

The secret sauce is in the design of the DWB geometry combined with tire parameter definitions and suspension parameter tuning to achieve REALISTIC telemetry data and suspension behavior.
This means that in racing sims with limited physics definitions the most realistic suspension design for a given vehicle does not necessarily agree with the name on the tin of the suspension definition ;-)

What makes a good car physics builder in AC is the understanding of which of the different definitions can be used creatively to achieve closest possible telemetry results. It is not as easy as 1+2=3

Two critical points
I do have though regarding the mod although overall I am really happy using it:
1) please pretty please remove the sound loop on all new VRC mods "This sound is created by Mr. Mike for ..." It is very annoying and it does actually interfere with game play in AC as every single time when changing to a VRC car in game this loop is played (not just on session entering)

2) suspension settings is too limited and inconsistent in the menu choices defined by setup.ini and needs some refinement (namely addition of damper setup choices on these prototype cars and refinements of clicks and steps and setup windows in some adjustments such as but not limited to tire pressure, alignment and ride height related settings).
I am sure these can be easily refined at a later point namely when aligning the cars performance once its rival/s are finalized in the pack.

It would also be really nice if especially for these cars where in racing quite some panel rubbing has taken place the mod would make use of AC damage features (both vanilla AC texture as well as CSP features).

I am looking forward to the next car. It will be an insta-buy as well.

I see that the physics will be re-evaluated by VRC, so no comment there, but to address a few things from this post for readers that may not know better:

Anti-squat is just a geometrical effect of the suspension, not some special technology - it’s ironically wrong on DWBs in vanilla AC due to incorrect force application, but as far as I know, fine on axle.

Correct suspension type is generally more important than camber adjustment, especially if you don’t have any accurate tire data (which, for a 1980s car, you absolutely don’t). Toe you can argue for since there’s no good way to offset it via curves if the car were to run very high angles. And anyway an approximation of semi-trailing or ML suspension via DWB is a lot more reasonable than a live axle approximation via DWB. The “high limitations” of axles in AC are just the lack of camber/toe adjustments (which generally wouldn’t fluctuate much once a reasonable setup had been established) and lack of lateral damping.

And on a car like this, it’s never about telemetry. You try to match engine/suspension/aero to the little known data and then work from there. Beyond that, it’s about trying to match laptimes and make the car feel correct based on what little real life reference might be available. For more modern cars, telemetry plays a larger part, but you have to have something to compare it to in the first place.

 

[Dirk Steffen]

First off, thank you for your extensive input and feedback, much appreciated.
Unfortunately removing the watermark will not be an option for me, for reasons I've stated (especially here on RD) multiple times. That doesn't mean I'm not looking for a more subtle solution, as I can understand this may be annoying at some point. However, this car being really the first one with multiple reports on that matter, I assumed most people would be okay with it, since I've included this message into my sounds for over two years now. I've already shortened the message by a fair amount, but like I said, maybe there's a more subtle solution that provides the same watermark effect.

It´s interesting you mention a loop, as this shouldn't be the case. The way I have it set up it should be played once and once only, on startup that is. Let me look into that again.

Thanks for looking into the possibility of using a more subtle means of marking the audio.
The issue is that the sound loop is not only played when entering the session once but it is played every single time (delayed) when jumping back into the car (it is even played when jumping into another persons car for a ride along if that car is a Chevrette such as you would often do in online racing on a server).

Perhaps a shorter recording mimicking pitlane radio is an option rather than the current long computer robot voice.

just skimming the thread, but @Dirk Steffen, AC totally does allow for anti squat/anti dive, some forms of true Multilink etc, just needs "maths" applied. Biggest issue with it is finding source materials.

Please re-read my post - that is exactly what I referred to.

I see that the physics will be re-evaluated by VRC, so no comment there, but to address a few things from this post for readers that may not know better:

Anti-squat is just a geometrical effect of the suspension, not some special technology - it’s ironically wrong on DWBs in vanilla AC due to incorrect force application, but as far as I know, fine on axle.

Correct suspension type is generally more important than camber adjustment, especially if you don’t have any accurate tire data (which, for a 1980s car, you absolutely don’t). Toe you can argue for since there’s no good way to offset it via curves if the car were to run very high angles. And anyway an approximation of semi-trailing or ML suspension via DWB is a lot more reasonable than a live axle approximation via DWB. The “high limitations” of axles in AC are just the lack of camber/toe adjustments (which generally wouldn’t fluctuate much once a reasonable setup had been established) and lack of lateral damping.

And on a car like this, it’s never about telemetry. You try to match engine/suspension/aero to the little known data and then work from there. Beyond that, it’s about trying to match laptimes and make the car feel correct based on what little real life reference might be available. For more modern cars, telemetry plays a larger part, but you have to have something to compare it to in the first place.

Undoubtedly the choice in vanilla AC suspension modding is very much subjective which workaround to resemble suspension systems is used.

I had conversations with several people on that topic and every one has their own take on what is best how.
Personally I like for the most part the restrictive live axle definition for production cars and vintage cars that ran a live axle as for these vehicles for the most part the limitation of not being able to alter toe and camber alignment is a lesser concern and stability can be gained in most cases through proper suspension alignment.

On a race car of the late 80's such as the IMSA GTO Camaro I would definitely weight the need of freedom to have setup options for toe and camber adjustments.

 

[Ghoults]

Undoubtedly the choice in vanilla AC suspension modding is very much subjective which workaround to resemble suspension systems is used.

It really isn't. In the end it comes down to physics. Dwb simply does not create the same kind of result when a wheel goes over bump or the car rolls in a corner. Not only are the unsprung masses different causing suspension settings and dampers have different effect but the way the solid rear axle for example steers when one wheel goes over bump is not possible to do on dwb. If you try to do it on dwb you get rear instability under braking and acceleration because in dwb if you have bump steer the rear end always steers when the suspension moves. In 4 link there is only steer if the suspension moves more on one side. Not to mention the tires are directly connected to each other. The tire camber gains are going to be different and good luck matching roll and squat characteristics of a solid rear axle with dwb setup. Whether you can do solid rear axle with dwb is not question of artistic choice. One creates what the car was/is, other is different kind of suspension.

The camaro probably ran biasply slicks at the time which did not like lots of camber due to their construction. And toe is is somewhat moot point as well because biasply tires wander around a lot more so you won't get the same kind of stability from adding little toe like you get with radials. And you would not want to run lots of toe on the rear anyways because it hurts the tires. So it is going to have some instability regardless. I also wonder how much rear camber and toe could a gto camaro from the mid 80s ran actually. I know top teams in transam in the late 70s ran floater rear axles which allow more adjustability. From that pov it does make sense a manufacturer and race winning would also have those gizmos in mid 80s but how much camber and toe was on the car is a different question.

The biggest issues for ac's solid axles are cars like any nascar which relies heavily on big tire angles on the rear. Same as the old v8supercar. Tons of camber. A race camaro from the mid 80s though? Not a lot.

 

[Andreas Knöpke]

 

[Qazdar Karim]

Yeah! I'm still trying to figure out the issue there.

 

[MHS]

Hi,

Just wanted to let everyone know we are taking note and re-working re-evaluating everything you have been pointing our. An update should be ready soon.
As we have all seen there's even a divided opinion in the whole comunity regarding the suspensions, and the best/more realistic way to get it represented ingame, so of course we want to apologize with everyone who felt dissapointed about the focus we took on it, but also please understand decisions were not taken lightly and even we had a debate about that, of which it came what we actually thought was going to be the best way to do it.

The car is great fun but the AI tends to flip over in some situations when driving over curbs.

We are also researching on that problem since.

I have also read a comment regarding the car don't having "damage features"; I would love to have more feedback on that, since the car actually has, as all our mods vanilla Assetto Corsa damage textures. In the case of this car, and having the rear spoiler animated, I felt damage displacement on those parts didn't look fine.
Some of our cars already have CSP deformable hoods, so that might be a nice feature I will add for next update.
Talking about that same aspect: features; in this car we added for the first time a CM Paintshop feature with which you can easily add your name to any skin/livery.

We will also take a look about how that audio message is played since it seems to be really bothering to some of you.

While we work hard to bring you an update as soon as possible, our modeller has been making some progress:

 

[F_B]

I've got a small example for the flipping
http://i.imgur.com/UB7J7eM.gifv

 

[gecco]

I expect the Audi to have minimum of 5 seconds turbo lag

 

[Dirk Steffen]

It really isn't. In the end it comes down to physics. Dwb simply does not create the same kind of result when a wheel goes over bump or the car rolls in a corner. Not only are the unsprung masses different causing suspension settings and dampers have different effect but the way the solid rear axle for example steers when one wheel goes over bump is not possible to do on dwb. If you try to do it on dwb you get rear instability under braking and acceleration because in dwb if you have bump steer the rear end always steers when the suspension moves. In 4 link there is only steer if the suspension moves more on one side. Not to mention the tires are directly connected to each other. The tire camber gains are going to be different and good luck matching roll and squat characteristics of a solid rear axle with dwb setup. Whether you can do solid rear axle with dwb is not question of artistic choice. One creates what the car was/is, other is different kind of suspension.

The camaro probably ran biasply slicks at the time which did not like lots of camber due to their construction. And toe is is somewhat moot point as well because biasply tires wander around a lot more so you won't get the same kind of stability from adding little toe like you get with radials. And you would not want to run lots of toe on the rear anyways because it hurts the tires. So it is going to have some instability regardless. I also wonder how much rear camber and toe could a gto camaro from the mid 80s ran actually. I know top teams in transam in the late 70s ran floater rear axles which allow more adjustability. From that pov it does make sense a manufacturer and race winning would also have those gizmos in mid 80s but how much camber and toe was on the car is a different question.

The biggest issues for ac's solid axles are cars like any nascar which relies heavily on big tire angles on the rear. Same as the old v8supercar. Tons of camber. A race camaro from the mid 80s though? Not a lot.

You have literally taken the issues I had mentioned earlier and expanded on them.
A few comments and corrections:

- mass differentials can be simulated with DWB (axle assembly masses are available for that - yes, cross wheel effects cannot be simulated as I had mentioned as one of the few downsides when using DWB)
- your mentioned bump steer concerns are luckily unfounded - here is where properly calculated and designed geometries come into play. you can design AC DWB systems where camber and toe differentials on suspension travel are small enough to succesfully mimick the behavior of a live axle in regards of dynamic camber and toe

The shortcoming of NOT being able at all to run ANY camber and toe angles than 0 deg in the AC live axle physics definition LARGELY out weights the downsides of loosing cross wheel effects in suspension behavior on the rear axle with performance cars as even with production cars with very mild camber and toe alignments the difference between running 0 deg rear toe and 0 deg rear camber and running a mild, conservative alignment on those production cars is DRASTIC in actual vehicle dynamics.

With performance cars, especially quite extreme performance cars such as the IMSA GTO that difference is even more substantial.
Because of the inability on a 600 HP+ car on racing slicks to run reasonable rear toe (+0.1 - 0.25 deg) and reasonable camber (-0.5 -1.5) on such a car the cornering behavior would be completely unrealistic (waaaay too extreme slip angles and waaaayy too small lateral g forces on that rear end then the actual cars would produce.

Sure you gain cross wheel suspension influences and nicety effects such as wheel hop when running a curb with one rear wheels but are these two effects worth loosing all the really important characteristics of a high powered race car on slick tires?

Also - yes, one can to a certain extent mitigate lower lateral g forces and greater slip angles by tweaking tire definitions - but unfortunately you can only get so far with that tool as unfortunately these tweaks are static and the moment you break that traction window the behavior of loosing grip on that rear end with tweaked compounds to mitigate 0 deg toe and camber suspension geometry to car goes away in a manner that is completely unrealstic for these cars.

THAT is the reason why I mentioned earlier that the choice of using the DWB physics definition in AC as a compromise is in such cases (high powered racing car on slick tires that definitely ran sufficient camber + toe alignments).

For vintage production cars or low powered cars or cars on sketchy tire compounds that is a completely different matter - hence it is ALWAYS at the discretion of the mod maker to decide which compromise is best.

On a car like this thoroughbred 600hp + prototype racer on slick tires that was build for road racing (constant changes of direction with various complex corners) it would not even be an option to think of using the Kunos AC live axle definition to simulate it's real life live axle - the scale really heavily weights towards the NEED for proper suspension alignment to simulate the cars actual behavior.

Thus are the short comings of the AC suspension model - perhaps at some point in the future we will have a more advanced option to properly simulate such scenarios - today we unfortunately have not :-(

Hi,

Just wanted to let everyone know we are taking note and re-working re-evaluating everything you have been pointing our. An update should be ready soon.
As we have all seen there's even a divided opinion in the whole comunity regarding the suspensions, and the best/more realistic way to get it represented ingame, so of course we want to apologize with everyone who felt dissapointed about the focus we took on it, but also please understand decisions were not taken lightly and even we had a debate about that, of which it came what we actually thought was going to be the best way to do it.



We are also researching on that problem since.

I have also read a comment regarding the car don't having "damage features"; I would love to have more feedback on that, since the car actually has, as all our mods vanilla Assetto Corsa damage textures. In the case of this car, and having the rear spoiler animated, I felt damage displacement on those parts didn't look fine.
Some of our cars already have CSP deformable hoods, so that might be a nice feature I will add for next update.
Talking about that same aspect: features; in this car we added for the first time a CM Paintshop feature with which you can easily add your name to any skin/livery.

We will also take a look about how that audio message is played since it seems to be really bothering to some of you.

While we work hard to bring you an update as soon as possible, our modeller has been making some progress:

I think you do a great job not only listening to users of VRC mods but actually being very transparent and engaging in discussions about your mods.

You are doing a great job, please do not let discussions about technical aspects deter you from thinking otherwise ;-)

Regarding damage - the "deformable object" feature with CSP can be beautifully used to deform other parts than the hood of course as long as the 3D objects are outright designed with this in mind.

I really hope you could use this for example to deform something like the rear bumper and the front fascia of the car - for this to work and look realistic the deformable area needs to be a single object, have no other objects (like light assemblies, etc) embedded and any possible gaps created during maximum deformation should be "plugged" by strategically placed black planes to not let the car model become "see through" or open transparent gaps.

This way quite substantial deformations can be created that really look realistic - this is not something that can be added ad hoc after finishing the car model but the car body needs to be designed, separated and layered with this feature in mind from the beginning.

Re. damage textures - I may need to test some more as I only saw a pristine Chevrette after a short race with some light body rubbing with AI cars. I may need to rub some more or perhaps I simply had damages switched off ;-) I am sorry if I caused confusion.

I am looking very much forward to the Audi - that is a truly visceral car in sound, flames and how it moved on the track + The Best Racing Driver Of All Time drove one - Walter Roehrl!

 

[Ghoults]

- your mentioned bump steer concerns are luckily unfounded - here is where properly calculated and designed geometries come into play. you can design AC DWB systems where camber and toe differentials on suspension travel are small enough to succesfully mimick the behavior of a live axle in regards of dynamic camber and toe

No it isn't. In dwb suspension to get any kind of steer effect you have two options. Set up an actual rear steer like in some skylines or add bumpsteer. Neither does cause roll steer like what happens in a 4 link. With bump steer your toe of each tire changes based on travel on the suspension. Any bump, braking or acceleration causes bumpsteer. In a 4 link you only get roll steer when the car rolls when it goes through the corner or when one side goes over bump. In straight line braking and acceleration toe stays 0. The numbers may be small and similar in size but the situtions when the toe changes happen are different which does not create similar effect.

Also - yes, one can to a certain extent mitigate lower lateral g forces and greater slip angles by tweaking tire definitions - but unfortunately you can only get so far with that tool as unfortunately these tweaks are static and the moment you break that traction window the behavior of loosing grip on that rear end with tweaked compounds to mitigate 0 deg toe and camber suspension geometry to car goes away in a manner that is completely unrealstic for these cars.

It is not a perfect fix but it does work. What do you mean by "car goes away in a manner that is completely unrealistic"? In the it is about matching tire forces through the corners and over the limit behaviour in ac is too forgiving anyways. You also talk about adjustments and I'm not sure adjustments even existed in this car. Sure it might have had small amount of toe and camber but adjustability is still question mark. Not to mention the biasply tires it ran don't really like much camber either.

On a car like this thoroughbred 600hp + prototype racer on slick tires that was build for road racing (constant changes of direction with various complex corners) it would not even be an option to think of using the Kunos AC live axle definition to simulate it's real life live axle - the scale really heavily weights towards the NEED for proper suspension alignment to simulate the cars actual behavior.

Having the actual real suspension is more important as it gives you the realistic pros and cons of that suspension. It is not perfect but it is still much closer to the real thing than any dwb hack. The solid axle model also gives more hope for the future as shaders patch can at some point add stuff like panhard bar height adjustments and antisquat adjustability with changing geometry. Maybe it already works.

 

[Dirk Steffen]

No it isn't. In dwb suspension to get any kind of steer effect you have two options. Set up an actual rear steer like in some skylines or add bumpsteer. Neither does cause roll steer like what happens in a 4 link. With bump steer your toe of each tire changes based on travel on the suspension. Any bump, braking or acceleration causes bumpsteer.

It is trivial to simulate a roll steer effect with a DBW setup due to the use of asymmetrical dynamic toe (bump/rebound where a static loaded suspension is approximately at a neutral toe setup).
With such a geometry the behavior of steer due to roll can be simulated while at the same time longitudinal force induction will result in equal steer forces L/R.
Again - not identical how the actual behaviors are induced but with a comparable outcome and behavior to the driver.

You also talk about adjustments and I'm not sure adjustments even existed in this car. Sure it might have had small amount of toe and camber but adjustability is still question mark. Not to mention the biasply tires it ran don't really like much camber either.

Camber + toe plates are used in practice and for different track setups different plates are used in the same manner as one would adjust an independent suspension for different camber and toe depending on balance, tire wear and track conditions. The late 1980's (especially in a premier racing series as the IMSA GTP/GTO/GTU teams ran in) were not the automotive stone age of the 1950's as you are making it out to be. People in these teams back then had substantial experience in high end race car design, suspension, chassis, aerodynamics already many, many years earlier since the dawn of Group 5 in the late 1970s hit the US racing scene.
To get a picture about the engineering level available in the IMSA series already in the EARLY 1980s just sign up to some of the facebook groups covering these cars such as the popular Porsche 935 facebook group - many mechanics, some drivers and team owners from teams in the late 70's through the early 90's are actively posting and engaging there.
Frankly I am quite surprised how "stone age ox cart tech" you make this IMSA GTO Camaro out to be.

Having the actual real suspension is more important as it gives you the realistic pros and cons

That is EXACTLY just the point I am trying to explain.
The available Kunos AC live axle physics definition IS NOT the live axle suspension simulating what would have been used in a late 1980's top of the line GT racing series.

It was in fact designed to produce believable suspension behavior of a very, very close to production car (in fact COMPLETELY production car suspension spec apart from perhaps used spring rates) of a Ford Escort or a Alfa Romeo GTA.

These cars did not have the 2 decades more modern tires, they did not have slick tires at all, they did not have 600hp +

This is my last post on the topic. Frankly it is quite sad that especially some people who do understand the actual underlying physics and limitations flat out click on disagree buttons instead of engaging in a discussion to help to clarify some of the myths.

As I wrote earlier - people are decided on how to deal with the live axle implementation and it's workarounds and there seems to be no grey medium - there are really only two completely decided camps on how to approach simulating modern live axle cars in AC which is a real shame as all EVERYBODY wants is the best and most realistic simulation after all - instead we have internet squabbles. Humans these days ...

 

[mclarenf1papa]

It is trivial to simulate a roll steer effect with a DBW setup due to the use of asymmetrical dynamic toe (bump/rebound where a static loaded suspension is approximately at a neutral toe setup).
With such a geometry the behavior of steer due to roll can be simulated while at the same time longitudinal force induction will result in equal steer forces L/R.
Again - not identical how the actual behaviors are induced but with a comparable outcome and behavior to the driver.



Camber + toe plates are used in practice and for different track setups different plates are used in the same manner as one would adjust an independent suspension for different camber and toe depending on balance, tire wear and track conditions. The late 1980's (especially in a premier racing series as the IMSA GTP/GTO/GTU teams ran in) were not the automotive stone age of the 1950's as you are making it out to be. People in these teams back then had substantial experience in high end race car design, suspension, chassis, aerodynamics already many, many years earlier since the dawn of Group 5 in the late 1970s hit the US racing scene.
To get a picture about the engineering level available in the IMSA series already in the EARLY 1980s just sign up to some of the facebook groups covering these cars such as the popular Porsche 935 facebook group - many mechanics, some drivers and team owners from teams in the late 70's through the early 90's are actively posting and engaging there.
Frankly I am quite surprised how "stone age ox cart tech" you make this IMSA GTO Camaro out to be.


That is EXACTLY just the point I am trying to explain.
The available Kunos AC live axle physics definition IS NOT the live axle suspension simulating what would have been used in a late 1980's top of the line GT racing series.

It was in fact designed to produce believable suspension behavior of a very, very close to production car (in fact COMPLETELY production car suspension spec apart from perhaps used spring rates) of a Ford Escort or a Alfa Romeo GTA.

These cars did not have the 2 decades more modern tires, they did not have slick tires at all, they did not have 600hp +

This is my last post on the topic. Frankly it is quite sad that especially some people who do understand the actual underlying physics and limitations flat out click on disagree buttons instead of engaging in a discussion to help to clarify some of the myths.

As I wrote earlier - people are decided on how to deal with the live axle implementation and it's workarounds and there seems to be no grey medium - there are really only two completely decided camps on how to approach simulating modern live axle cars in AC which is a real shame as all EVERYBODY wants is the best and most realistic simulation after all - instead we have internet squabbles. Humans these days ...

We hit the disagree button instead of responding because this is what happens when we respond. For what it’s worth, I responded earlier to clarify some of the “myths” you’d written to the broader audience that might otherwise be taken in by your...exuberance.

The effects of rear toe are a lot smaller than you insinuate and camber can be effectively taken care of by adjusting the grip of the rear tires and their camber curves (not like those are based on real data anyway). There are additionally other things that can be done with e.g. camber thrust of the tires to mimic toe alignment. Otherwise, I agree with Ghoults (and btw, you’re still missing his point about bumpsteer).

In any case, I think the whole argument is pointless considering the majority of the car has been made up anyway (little reliable data for cars of the era). It doesn’t claim to be an ultra-realistic representation of a real car - regardless of whether or not it likely should be, as payware at RSS prices - and therefore shouldn’t be treated as such. You get what’s advertised. If the general public knew how obscenely inaccurate many (most?) of the Kunos cars are - some aspects still continuing to this day with ACC, I don’t think this would be a discussion.

 

[AlleyViper]

Out of curiosity, were these GTO cars using bias ply in very late 80s or moved to radials?

Regarding sound watermarks, some sound designers resort to leave them on horn for racing cars, it can be less intrusive for the player (specially on payware).