ST205 centre of gravity Options

[rhodesyboy]

Hi, I am just wondering has anybody ever calculated the centre of gravity on an st205?

Could do with it for my assignment at university as I am doing it on my st205, I'll then be able to calculate the roll centre and then determine what kind of body roll and how well developed the suspension is in comparison to the car. I can calculate roll centre but not centre of gravity as I'm fairly sure you need scales and need to be able to lift the car a certain amount to calculate it accurately.

So if anybody has gone this in depth and has recorded it could you please send it to me?

Cheers

[azian_advanced]

Here's the location of the centre of gravity along the longitudinal axis.

[rhodesyboy]

cheers but I think I need it more along the lateral and vertical axis, so is it centred to the car and how far is it off the ground.

[Wild202]

cheers but I think I need it more along the lateral and vertical axis, so is it centred to the car and how far is it off the ground.

I think that the height from the ground depends on the spring, do not you?
Not all are OEM springs. I TRD example are they below.

[rhodesyboy]

Yes but I'm not talking about ride height I'm talking about centre of gravity.
So basically the point that the mass of the car rolls around so couple that with the roll centre at the centreline of the car and this will give you an idea on how much body roll you will get, I think the further away the roll center is from the centre of gravity the more body roll you will get in theory, obviously there is more to it than that but that's a massive factor to take into account.

Lowering the car will only bring the centre of gravity closer to the floor it won't affect where it is on the car itself.

[rhodesyboy]

Ah actually my bad I did say how far it is from the ground, I meant where it is on the cars body.
Because obviously lowering it will change how far it is from the ground.

[Wild202]

The center of gravity and weight distribution is very different concepts.
The weight distribution on the vehicle axles, I mean.

This post has been edited by Wild202: Feb 12, 2017 - 5:39 AM

[Wild202]

Of course, I may not understand everything correctly due to the translation.
If I wrote nonsense, then I apologize.

[rhodesyboy]

It's my bad man I worded it wrong, I said how far it is off the ground so then going to ride height is understandable

[VavAlephVav]

I think you could estimate it well enough with some thoughtful assumptions.
Take the longitude point from the diagram that Aizan Advanced posted, then know that it will be vertically above that point.
Then I would say it is safe to assume that vertically it will be somewhere between the bottom of the car and a point not higher than where the windows begin, or not higher than the motor.
You might estimate it as right about the middle of the door and test to see how the numbers work out.

[rhodesyboy]

Yeah an estimation would be possible the only problem with that would be the tutors tend to be quite strict in terms of referencing and for me to just say "the centre of gravity is here" and then back it up by saying "I estimated it", probably won't fly in all honesty, then I could potentially lose a few marks because of it.

[bryanf]

If you have access to scales you can calculate the cg by raising one end and finding the weight change.

http://www.longacreracing.com/technical-ar...aspx?item=42586

http://www.speed-wiz.com/calculations/chas...sis-weights.htm

[azian_advanced]

cheers but I think I need it more along the lateral and vertical axis, so is it centred to the car and how far is it off the ground.

Here are the corner weight results. Not sure if this helps.



Source: gtfours.co.uk

[rhodesyboy]

Cheers mate, had a quick look around and yeah it seems like the only way to calculate centre of gravity without estimating is by lifting it whilst it's on some scales and calculating it, my university does have corner weight scales so might just see if I can arrange to do it in college at some point.

Not sure on the weight limits actually, I think they are for the formula fords so they might have a really low weight limit.