question about somes car attributes

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question about somes car attributes

Postby nonobecane » Mon Jul 14, 2014 1:47 pm

Hi,
At the first, I'm sorry for my english language, I'm french and i speek english like a Spanish cow :oops: .

I Try to make this car. My 3D model isn't good for the moment but at first I try to finish the settings, particulary the road behavior. normaly this car is oversteering
Image Image

Can you explain me the difference between this two line for the engine brake?
Code: Select all
  <section name="Engine">
....
    <attnum name="brake linear coefficient" val="0.15"/>
    <attnum name="brake coefficient" val="0.25"/>
...


And this One. It's the for the slide when wheels is block ?
Code: Select all
    <!-- Adherence -->
...
    <attnum name="dynamic friction" unit="%" val="65"/>
...


Thank you for your help

Arno
Image SD2 svn / Debian Sid 64 / 1920x1080 on GTX580 / Logitech G25
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Re: question about somes car attributes

Postby Haruna » Tue Jul 15, 2014 4:58 am

Basically:
Brake Coefficient determines how much engine braking you get. Higher values = more engine braking, and thus increased oversteer sliding when not on the throttle.
Dynamic Friction controls the way grip drops off when skidding. Higher values don't stop the "blocking" however.
You might also want to tone down the brake pressure, the friction of the brakes, or brake sizes.

A combination of all these changes should stop you from spinning off a cliff if you lift the throttle.
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Re: question about somes car attributes

Postby nonobecane » Tue Jul 15, 2014 6:02 am

Thank You for your answer Haruna,

But what the difference between :
"brake linear coefficient" and "brake coefficient" ?

brake linear coefficient is linear and brake coefficient depend of the engine torque ? It's that ?
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Re: question about somes car attributes

Postby chad3006 » Tue Jul 15, 2014 1:06 pm

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Re: question about somes car attributes

Postby nonobecane » Tue Jul 15, 2014 4:56 pm

Thanks, for this 2 good links, chad3006.

On this link http://sourceforge.net/p/speed-dreams/wiki/36GPSetup/ I understand it's "brake coefficient" which depend of torque.

An other question ;)
What settings can you suggest to simulate a rigid axle ?
like this : Image

I play with "Anti-Roll Bar" but i'm not happy of the result

Thank you in advance
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Re: question about somes car attributes

Postby chad3006 » Tue Jul 15, 2014 7:18 pm

nonobecane wrote:What settings can you suggest to simulate a rigid axle ?


I'd start by adjusting the "springs" under the suspension section of the XML file. Maybe set the stiffness to a ridiculously high setting and see what that does. I don't know if there is an upper limit built into SD or not.

Code: Select all
    <attnum name="spring" unit="lbs/in" val="1400"/>
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Re: question about somes car attributes

Postby nonobecane » Tue Jul 15, 2014 8:21 pm

Thank you chad3006
Are you sure ? I think sping must be soft. No?
Image
(image extract of http://calencar.free.fr/escort/index.htm)
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Re: question about somes car attributes

Postby chad3006 » Tue Jul 15, 2014 8:59 pm

Well, we must be talking about two different things. To me, a rigid axle is solidly attached (welded) to the chassis – some drag racing cars do this. I guess you're talking about what I would call a solid axle, (not an independent suspension type.) You might try downloading my Cortina, if I remember right, I had it setup for a solid rear axle – you could use that as a starting point anyway.
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Re: question about somes car attributes

Postby nonobecane » Wed Jul 16, 2014 6:24 am

Sorry, my english is too bad, In french the name for the solid axle is "essieu rigide" and i translate it word at word. :oops:

I 've allready start my suspension settings with your milano-legaro (approximatively the same mass).

I move a lot of suspension settings, I think i must restart probably with your spirit-consultina.

Thank you
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Re: question about somes car attributes

Postby chad3006 » Wed Jul 16, 2014 12:35 pm

No problem, the misunderstanding could just as easily happen between two English speakers.

If you already have the Milano Leggaro, you probably won't find much differences between that and my Consultina in the suspension area. I'm certainly no expert at car setups, but I'd recommend you just keep making adjustments to "springs", "anti-roll bar", and "stiffness," until you find what you are looking for.
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