Car's Center Of Gravity

[Mandic 0]

Since the topic about "Suspension And How It Works" has been closed I'm forced to open a new one...

 

So, does anyone how high (+/-) the center of gravity is on an avarage car? Is something like 70cm (+/-15) about right?

 

Thanks

 

Ziga

[Gentrix 2 1 Cars]

Rear Seats laid down or not?

 

 

 

 

 

 

andi

[Mandic 0]

 

Will the car go faster if they are down, due to better aerodynamics?

 

Well I know there are so many things that influence on COG, but an +/- 20cm is good enough approximation, just interested whereabouts it is.

 

Cheers

 

Ziga

[Gentrix 2 1 Cars]

... if I remember correctly, it had something to do with a 1.1 Nova and it´s "go faster" mods. *g*

 

 

andi

[Mandic 0]

Yeah LOL, I think the owner thought that his car is faster from 0-60 with lowered seats or something due to lower gravity, like Earth gravity, LOL

 

Anyway, back to the topic...

 

Cheers

 

Ziga

[jonah 1]

For a 205 I would estimate somewhere between 50 and 60cm. It has to be lower than (track width + tyre width)/2, otherwise the car would tip over with 1G of lateral acceleration, which is possible with decent tyres on a good surface.

[Mandic 0]

Makes sense!

 

Cheers

 

Ziga

[crogthomas 0]

A rough rule of thumb is that the CoG is usually at approximately the same height as the centre of the crankshaft.

[eeyore 0]

the crank centerline is always a safe bet

[sutol 0]

If you knew exactly where it was and it was marked out for you............in what way would this help you become a better driver or make the car go faster I'm interested

[Richie-Van-GTi 73 2 Cars]

If you knew exactly where it was and it was marked out for you............in what way would this help you become a better driver or make the car go faster I'm interested

 

 

it wouldnt make you a better driver, but it would give you an excellent insight as to where you need to remove weight in order to lower the CoG and thus increase stability.

[sutol 0]

it wouldnt make you a better driver, but it would give you an excellent insight as to where you need to remove weight in order to lower the CoG and thus increase stability.

When building a race car weight is kept as low as poss anyway and there should be no room for improvement when the car is finished.

When converting a road car to go fast then anything and everything should be located as low as poss to lower the centre of gravity but I've never heard of anyone who knows exactly where this centre is.

It would be in a different place at the back/middle/front so I wouldn't bother too much about it. Just get all weight as low as poss and concentrate on the corner weights.

That's my opinion anyway

 

V6 nearly ready

[Rob_the_Sparky 10]

it wouldnt make you a better driver, but it would give you an excellent insight as to where you need to remove weight in order to lower the CoG and thus increase stability.

 

Errm, that isn't that hard, weight high up = bad. Personally I think front to back weight is where careful removal/movement of weight is of more concern. You don't want to remove all the weight from the rear end making an already poor front to rear ratio worse (although it is easiest to do this).

 

Measuring a CoG is not a short job, we do it at work and requires a large jig to measure the height of the CoG, basically putting it on its side. Not really that compatible with oil, water and driver in the car!

 

Rob

 

P.S. I'm surprised it is that low you think it is given the amount of weight above that point

 

P.P.S. You can exceed 1g lateral force with a CoG higher that the centre of the axle. The angle between contact point and CoG is what matters, with 45degrees being the point at which you would start tipping for a lateral of 1g. That angle will depend on how far from the wheel the CoG is (sideways) as well as its height, of course all of that is for static loading and dynamic loading is much more complex (and my knowledge runs out).