n smikle's LMP car

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.

Post Sat Mar 12, 2011 7:22 pm

The % of antidive means basically the % of longitudinal weight transfer that will go through the wishbones rather than spring+damper.

100%antidive would mean the car does not dive at all. 150% antidive would mean the front actually lifts while breaking. You also have antisquat, antilift,etc.


All this determine a "pitch center" which would be(suposedly) the point where the car rotates, as seen from lateral view.

There's lots of discussion as where that point should be. I don't really know and don't give much importance to that( should I?).

You can say(similar to what with roll center, but in lateral view) that if the pitch center is behind the car(rear axle), both suspensions will compress when breaking, and extend when accelerating.


It's basically the same thing of roll center but in lateral view.

One could also talk of %anti-roll, which would be 100% if the roll center was at CoG height.


Hope I answered your question.



EDIT: As an example of the uses of these, those anti's generate "instant" weight transfer which could be bad. I know a FWD car that used 100%antilift in the front because it was very sensitive to height changes(aerodynamic reasons). Every time they throttled out of a corner the nose raised and understeered, hence the reason.


EDIT2:

"The pitch axis is a line drawn between the left and right pitch centers. This is the axis about which the suspended mass pitches about. This axis is often called the kinematics pitch axis."
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Come back 747, we miss you!!
Caito
 
Joined: 16 Jun 2009
Location: Argentina

Post Sun Mar 13, 2011 5:46 am

edit..
"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Sun Mar 13, 2011 5:50 am

My rear suspension has the mounts horizontal.
So it is not allowed to rotate in pitch via the control arms? (only through compliance of the joint and rotation around the wheel centre? correct? it essentially moves up and down.

That means if the front has horizonal axis too:

1. all the forces go into the front suspension IF the front lowers
2. If the back lowers all the forces go into the rear susp.
3.OR the other situation is the car can does not pitch any at all (just lowers or raises front and back same time). - Ok so horizontal Arm axes can give diffrent results regarding pitching. I think this is out of my control. if I make both front and back axes horixontal (parallel).

Actually, i have anti dive on the front. So each front suspension can pitch about thier own axes. A line from this to the front contact patch intersects the line from the rear pitch center which is at infinity at the same front contact patch. Hence my pitch center is at the front contact patch.

Does it cancel it out if it's on the ground? reading some stuff after googling..
"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Mon Apr 18, 2011 3:47 am

Starting the body. I am getting the hand of making these surfaces, not totally good at making surfaces yet, but getting there. Shape is simple and manufacture-able.

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"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Fri Apr 22, 2011 2:18 am

I like this concept on the aston martin

http://www.mulsannescorner.com/newsmarch11.html

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"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Tue May 17, 2011 2:04 am

Some refinements. The long control arms - I hope they actually allow me to do what I envisioned which is a Ground effect body with double diffuser. It still seems kinda tight. I guess that is the side effect of putting the engine in the front and not behind the driver.

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"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Tue May 17, 2011 9:41 pm

Nice to see you progressing. You really get something going there.
Also I am really no fan of those separated wheel covers but that’s just some question of fashion. There should either be open wheels or everything should be covered like on a LeMans or touring car.
mep
 
Joined: 11 Oct 2003
Location: Germany

Post Wed May 18, 2011 1:31 am

Yes, It will look similar to the Lemans cars; doing some light, visual research on how I am going to design that bodywork between the fenders and the fuselage.
"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Sat Jun 04, 2011 1:42 am

coming up with a overall theme for the car is trickier than I thought!
Trying to work in a front diffuer and wing.. some barge boards etc. I don't know how exactly this is going to turn out..

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"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Sat Jun 04, 2011 2:03 am

I like that. Do you plan on building it some day? Or just practice?
Come back 747, we miss you!!
Caito
 
Joined: 16 Jun 2009
Location: Argentina

Post Sat Jun 04, 2011 5:02 pm

If I get the money to build it I would. For now it is practice.
"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Thu Jun 23, 2011 5:42 pm

How the tunnels at the rear is used for downforce is interesting. In Gordon Murray's Batmobile, which has a similar "long control arm" philosophy.

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"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

Post Fri Nov 04, 2011 5:24 pm

will start back working on this.
"I was blessed with the ability to understand how cars move," he explains. "You know how in 'The Matrix,' he can see the matrix? When I'm driving, I see the lines."
n smikle
 
Joined: 12 Jun 2008

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