Exploding physics with stiff suspensions

[Associat0r]

So I just tried the RSR Dallara F3 which is supposed to have physics from real data.
But when I increase the rear wheel rates in combination with high fast rebound dampers in the garage, the physics engine sadly explodes.
https://i.gyazo.com/c9b4289203f11227aefdc7754ae950f3.mp4

EDIT: See here on how to reproduce it http://www.racedepartment.com/threads/exploding-physics-with-stiff-suspensions.123651/#post-2269476

 

[Qazdar Karim]

Slide all 16 damper settings on the F312 fully to the max and it happens. It's a problem with the rear axle oscillating that seems to be most directly impacted by the rear fast bump/rebound. When I tune anything to below 95% of the max it stops (and the max is 14000, realistic in a race setup is like... 2000)

I kinda suspect it's also affected by rear bumpstops or something cause I've tried similarly stiff setups for other cars and it doesn't happen.

I always had the "feeling" that there is something wrong with the rear axle on AC.
The fact that the engineer app is unable to calculate damping ratios when you have only a heave spring + arb at the rear is maybe a small indication, it's a not a good way to draw conclusions (i know), but i believe that they probably used the same code for the rear,knowing that it works well for the front. Also, when i calculate damping ratios manually i get different results comapred to that app for the rear, but i get the same results for the front.

 

[IgnacioK]

There is a specific setup to check this? becouse i cant get the same result
I have tested with the F312T using this:

SUSPENSION :
wheel rate to MAX ( all )
ARBs to MAX ( all )
DAMPERS :
all values to MAX

Even checked with the curbs of silverstone (the big ones) and i cant get the same effect .

 

[Austin Ogonoski]

I always had the "feeling" that there is something wrong with the rear axle on AC.
The fact that the engineer app is unable to calculate damping ratios when you have only a heave spring + arb at the rear is maybe a small indication, it's a not a good way to draw conclusions (i know), but i believe that they probably used the same code for the rear,knowing that it works well for the front. Also, when i calculate damping ratios manually i get different results comapred to that app for the rear, but i get the same results for the front.

What a boring life must someone have when he tells the same stuff over and over and over again? About a game. Please, Qazdar, do us all a favour and look for a new hobby. Or enjoy the nice weather and perhaps have a beer? Or even two?!

 

[Qazdar Karim]

I prefer vodka mate

 

[Christian Moreau]

You guys really need to quit the sass and just move on. Name calling and trolling won't get you anywhere and it's definitely not what this community is about.

 

[David Dominguez]

Anyway, there is no need to make a circus of this, at best it's only problematic in very specific situations, and as I said even rF1 had similar issues (plus other funny issues regarding to damping and multiplayer). But on the other hand, there is also no need to go ultra defensive with the game, or accuse the mod to be wrong/unrealistic/not updated (I've seen many comments like this in PRC), I know that Andrea had a lot of data and took the development of the physics very seriously and carefuly, so I would trust in his work.

Just accept that there is a little minor issue that doesn't affect really the gameplay and move on.

 

[Qazdar Karim]

Especially that Stefano himself confirmed this in some streamings... Yes! rF2 handles this better but it's not the end of the world either for other sims

 

[LilSki]

Anyway, there is no need to make a circus of this, at best it's only problematic in very specific situations, and as I said even rF1 had similar issues (plus other funny issues regarding to damping and multiplayer). But on the other hand, there is also no need to go ultra defensive with the game, or accuse the mod to be wrong/unrealistic/not updated (I've seen many comments like this in PRC), I know that Andrea had a lot of data and took the development of the physics very seriously and carefuly, so I would trust in his work.

Just accept that there is a little minor issue that doesn't affect really the gameplay and move on.

Too late for that...

 

[Baki]

There is a specific setup to check this? becouse i cant get the same result
I have tested with the F312T using this:

SUSPENSION :
wheel rate to MAX ( all )
ARBs to MAX ( all )
DAMPERS :
all values to MAX

Even checked with the curbs of silverstone (the big ones) and i cant get the same effect .

I did the same on Mugello. I wasted my time for this bullshit. Nothing exploded.

Anyway, there is no need to make a circus of this, at best it's only problematic in very specific situations, and as I said even rF1 had similar issues (plus other funny issues regarding to damping and multiplayer). But on the other hand, there is also no need to go ultra defensive with the game, or accuse the mod to be wrong/unrealistic/not updated (I've seen many comments like this in PRC), I know that Andrea had a lot of data and took the development of the physics very seriously and carefuly, so I would trust in his work.

Just accept that there is a little minor issue that doesn't affect really the gameplay and move on.

Thanks David but that makes me now more lol

 

[Associat0r]

Loosing out more than 25% of stiffness range in addition to the global damping decrease hack is not a minor issue, and certainly something to make a major circus about, and majorly affects the simplay.

 

[ZethGAF]

This happens while stopped/rolling? Doesn't suspension and stuff have a separate behavior under 5mph?

 

[Associat0r]

This happens while stopped/rolling??

In this car it happens when you start rolling, but it can also happen (not this car) while not having moved yet.

Doesn't suspension and stuff have a separate behavior under 5mph?

According to the devs, this only applies to the tire model, but if so, stuff like this shouldn't happen.

 

[Andrea Lojelo]

Thanks a lot for the very detailed bug report.
Indeed a PM would have been enough to fix the problem.
I feel pretty honored to have an article about our car in one of the most read blog ever

The reason behind this bug is very simple: I forgot to set min/max values for damper values in the setup.
We never noticed the issue, since we do our setups based on real values.

The base setup is the real setup used by the Omicron team at Spa in real life.

Those dampers have 2 settings with 8 positions (1-8). In reality you can't even set Fast and Slow as you want, but you have only 1 setting for bump and one for rebound.


Here is part of the calculations I've done for the dampers:

and below a detail of the min/default/max settings.

As you can see the maximum values currently set in the setup menu are way off, and in the case of the Front Fast Bump the maximum real value isn't reachable.



I'll fix that in the next release of the car that will most probably come after AC v1.7.
I will include also the new cool features that KS has introduced in the new AC version (Brakes temperatures, tyre v10...)

Those are the values you need to put in AC.

Bottom line, with correct values, there are no crazy explosions.
With completely wrong values, weird things might happen, but that's absolutely normal.

I've been always very happy with AC, and very impressed by the way it matches reality (comparing telemetry) when accurate data is used.

 

[PhilS13]

You forgot to put some majorlys in there.

 

[jim lloyd]

Hehe SHUT DOWN . Thread over

 

[Deleted member 130869]

Thanks a lot for the very detailed bug report.
Indeed a PM would have been enough to fix the problem.
I feel pretty honored to have an article about our car in one of the most read blog ever

The reason behind this bug is very simple: I forgot to set min/max values for damper values in the setup.
We never noticed the issue, since we do our setups based on real values.

The base setup is the real setup used by the Omicron team at Spa in real life.

Those dampers have 2 settings with 8 positions (1-8). In reality you can't even set Fast and Slow as you want, but you have only 1 setting for bump and one for rebound.


Here is part of the calculations I've done for the dampers:

and below a detail of the min/default/max settings.

As you can see the maximum values currently set in the setup menu are way off, and in the case of the Front Fast Bump the maximum real value isn't reachable.



I'll fix that in the next release of the car that will most probably come after AC v1.7.
I will include also the new cool features that KS has introduced in the new AC version (Brakes temperatures, tyre v10...)

Those are the values you need to put in AC.

Bottom line, with correct values, there are no crazy explosions.
With completely wrong values, weird things might happen, but that's absolutely normal.

I've been always very happy with AC, and very impressed by the way it matches reality (comparing telemetry) when accurate data is used.

Mod Edit: Breach of privacy and doxing is not permitted unless permission has been explicitly granted by the directly affected party. This is the second time you have done this within the 6 month warning period, Gui. See you in 7 days.

 

[Jim Liak]

I've been always very happy with AC, and very impressed by the way it matches reality (comparing telemetry) when accurate data is used.

@Associat0r really curious what you will say.

 

[seanvdburg]

Loosing out more than 25% of stiffness range in addition to the global damping decrease hack is not a minor issue, and certainly something to make a major circus about, and majorly affects the simplay.

Thanks for another major facepalm.

 

[RMR1]

@Associat0r really curious what you will say.

He was blown out of the water, he will say nothing until he found a new source of attention.

 

[AndrewBo]

According to THIS post..........
At this point the relevant discussion is dead, and so shall be the thread.