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Kunos Simulazioni - Assetto Corsa
(8874 posts, started )
I just spent the time I could be calculating those dynamic indexes to post a rant on the ac forum about the topic. Big grin
I'd assume it is yaw. So if you calculate one you can probably use the same multiplier for the other inertias as well. So if the yaw dynamic index is too low then raise it and raise the other 2 as well using that same multiplier?
I'd go with the tiny box you calculated and I'd bring the tires DX DY closer to each other. See how that feels

I get a yaw DI of 0.72 and the tiny box gets a DI close to that in AC.
The formula_k uses
INERTIA=1.9,0.8,3.4
And the box:
INERTIA=1.89,0.56,3.75

I have some doubts...
Aris : - The car inertia in the car.ini is calculated as a box. The calculations inside AC are made in a way that if you put the rough dimensions of the car, you get a pretty good inertia values.

So it isn't as simple as take the known inertias and size a box to match that. There is a multiplier or another calculation built inside AC.

Still he is saying that Dynamic Index is a very good tool and the only way to get close to 0.72 yaw DI on your car is to have a small box
Maybe the weight of the car is the multiplier.
No it has to be something on top of that.

What I mean is the way you calculated the box dimensions cannot work in AC. For AC the box dimensions are not the dimensions of a box that has the same inertias and mass as the car. This is what you calculated, a box(x,y,z) that weighs 1450 kg and has 2130,469,1738 inertias. AC does not want that as an input.

About the Dynamic Index, changing box width does not affect its value. Changing box length, box height and mass(wtf? it really shouldn't) affect its value. That means the DI we see in AC is based on mass and pitch inertia alone. Not yaw, not roll.
Quote from PhilS13 :Changing box length, box height and mass(wtf? it really shouldn't) affect its value. That means the DI we see in AC is based on mass and pitch inertia alone. Not yaw, not roll.

Mass does affect the yaw dynamic index...

e.g. Yaw DI = k^2 / ab, given that k^2 = Iz / m

As far as I can tell AC wants the input for car.ini as INERTIA=width,height,length (whole vehicle values i.e. not track,height,wheelbase).

At least that's what every good mod seems to use (except in cases like the AC Cobra which uses a lower height value in car.ini. I assume that this is due to the fact that it doesn't have a roof and the windowscreen would only count for 1% of the cars overall mass or something).
In light of this inertia discussion, I made some small changes to my mod car and I think it feels better: https://www.mediafire.com/?1lmlkymy7lk6acq,ukf7dvrf38fzqar

Things I noticed:
- handles like shit with DI 0.72. Just, no.
- increasing the width value to just 0.01 beyond the actual width of the car caused it to want to rotate constantly, but 0.01 less feels great.
- values significantly lower than the physical dimensions of the car cause the car to drive as if it was on rails and handle bumps far too well.
Quote from JackDaMaster :
Quote from PhilS13 :Changing box length, box height and mass(wtf? it really shouldn't) affect its value. That means the DI we see in AC is based on mass and pitch inertia alone. Not yaw, not roll.

Mass does affect the yaw dynamic index...

e.g. Yaw DI = k^2 / ab, given that k^2 = Iz / m

As far as I can tell AC wants the input for car.ini as INERTIA=width,height,length (whole vehicle values i.e. not track,height,wheelbase).

At least that's what every good mod seems to use (except in cases like the AC Cobra which uses a lower height value in car.ini. I assume that this is due to the fact that it doesn't have a roof and the windowscreen would only count for 1% of the cars overall mass or something).

Mass is already in the Iz. You divide by m to get k. Both masses cancel each other out.
Quote from PhilS13 :
Quote from JackDaMaster :
Quote from PhilS13 :Changing box length, box height and mass(wtf? it really shouldn't) affect its value. That means the DI we see in AC is based on mass and pitch inertia alone. Not yaw, not roll.

Mass does affect the yaw dynamic index...

e.g. Yaw DI = k^2 / ab, given that k^2 = Iz / m

As far as I can tell AC wants the input for car.ini as INERTIA=width,height,length (whole vehicle values i.e. not track,height,wheelbase).

At least that's what every good mod seems to use (except in cases like the AC Cobra which uses a lower height value in car.ini. I assume that this is due to the fact that it doesn't have a roof and the windowscreen would only count for 1% of the cars overall mass or something).

Mass is already in the Iz. You divide by m to get k. Both masses cancel each other out.

Thanks. I thought I was missing something in regards to that.
fml. For some reason yesterday I have decided to delete tyres.ini, suspension.ini and car.ini. So now I need to make all those changes again I made yesterday.

But who cares. All the important stuff is right here in this image:
So the M3 E92 has DI of 1,119...
1.079 here

I tried your car with E92 specs

0.52 Weight dist
1580 kg
2.76 wheelbase
1.8,1.43,4.62 box

Gave me a DI 1.275

Then I found out that changing HUB_MASS changes DI...nice. As long as we don't how DI in assetto is calculated trying to match a real life DI with this obscure value is worthless
The updates for Sierra Cossworth and Ibiza mods from Bobskype, too good now, especially the stock Sierra.
Don't forget the NSX
Yes, but only after Bobskype's suggested Toe values (the real values).
I always adjust the Toe values, because the default ones are usually factory spec, so the inexperienced customers don't crash
This is true not for only regular cars, also for high performance ones.
Here is very good quote form guy that do alinements for bmw e36m3
Quote :The BMW factory specs care nothing for performance or tire wear, only for safety and a low % of lawsuits. YES I AM SAYING THAT THE BMW FACTORY SPECS WILL NOT ONLY GIVE YOU POOR HANDLING AND PERFORMANCE, IT MAY ALSO WEAR OUT YOUR TIRES PREMATURELY.

Full article
http://www.bimmerforums.com/fo ... ent-Guide-for-your-E36-M3
I gotta get some knowledge on car setups ASAP. I'm totally clueless Frown Especially cause a few clicks here and there can make a car feel twice as good..


Smile
Great skin. There is also a wheel painting template in the ac thread. Just don't use the mask layer of that template. It makes the holes on the wheels appear as if you were looking through the car.
Top quality track that Luccaring. Ruf is a best even on semis, shame my concentration was a bit off, but great racing nevertheless with you guys.
Thx for the server Troy!
Quote from dawesdust_12 :How do I make AC not look like ass:

You are wasting horsepower Dave, no need for such high fps, crank up the graphics
This is what I see with my outdated 5 year old machine
My settings
http://www.bildites.lv/images/m9p52c6ppbtx9ah9t9rg.jpg
Same place, maxed out settings
http://www.bildites.lv/images/4eoebg5cibtaooug6ht7.jpg
Things are fairly maxed out. There's just weird mip issues and jaggies. I don't understand it entirely. I'm gonna try to fix it tonight.

Kunos Simulazioni - Assetto Corsa
(8874 posts, started )
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