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Centre of gravity

Centre of Gravity

The centre of gravity is perhaps the single most critical area of any racing car weight consideration. It must be as low as possible to the ground, and this is not only because the weight act through it, but also because all accelerative forces of acceleration, braking and cornering work trough it.
Any force that acts through the CoG has no tendency to make the car rotate.

Center of gravity location can be defined as:
- The balance point of an object
- The point through which a force will cause pure translation
- The point about which gravity moments are balanced

The center of gravity (CoG) is also called center of mass.

The center of gravity location must be referenced to a 3 dimensional coordinate system. CoG location is directly a function of the coordinate system in which it is referenced. It is measured relative to a reference datum using moment balance equations.

If you apply the force in a direction that does not pass through the CoG, it will make the car rotate unless it is balanced by another force.
For a racing car, the CoG is located between the front and rear wheels and as close to the ground as physically possible.

You know from traveling in a road car that when the driver brakes, the car dives down at the front. Equally, you have experienced rolling in corners, and squat - the car sitting down in acceleration if you put your foot down hard enough. These movements you feel are accelerative forces, and they are acting through the centre of gravity. Much of their control is owed to suspension design, but a high centre of gravity won't help. Lower center of gravity - less rolling, squatting and diving, less weight transfer.

However, it is not only vertical centre of gravity position designers are interested in - it must be on the centerline of the car, and its position between the front and rear wheels will determine how the braking and accelerative forces are spread between front-rear or left-right wheels. It is good to have the static weight distribution tuned in way that the centre of gravity is positioned closer to the rear of the car, as this puts more weight on the rear wheels and provides more traction, but some F1 teams think differently (see Weight Balance).

As well as this, the vehicle should have a low polar moment of inertia. This basically means how easy it is to move car around, and if the designer concentrates the weight close to the centre of gravity, he can achieve this, and obtain a responsive racecar. These criteria is, of course, also dependent on where the wheels are in the first place - and the F1 wheelbases are so long that with a low centre of gravity and such stiff suspension, squat and dive are significantly minimized. Any wheelbase changes are often to change static load distribution and reduce weight transfer rather than improving stability.

 

There is only few companies in the world manufacturing Centre of the gravity machine. They are a highly sophisticated and expensive piece of equipment.
One of them is Space Electronics, the world's number one manufacturer of aerospace mass properties measurement instruments.

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Books to read


Some useful links:

Technical
- f1technical.net, a great site with a lot of technical information’s and explanations. Site is updated daily with news from F1 word.

Autosport
 - autosport.com, This site is a legend. A bible for racing lovers. News from all around the word. Unfortunately, to get access to all news, interviews and to open the site completely you should be subscribed to Autosport magazine. Anyway, great read.

James Allen on F1
- JA.F1 site (or blog) ovned by ITV Sport’s lead commentator on Formula 1 James Allen

Joe Saward blog
- joesaward is the Joe Saward official blog about Formula 1 world. Joe is an journalist, who write primarily about politics in and around motorsport, specifically on the FIA Formula 1 World Championship

Vital F1
 - vitalf1.com/ is another great site for Motor Sports fan’s like me. Site is relatively new, but great fun, with great discussion forum, Formula 1 news and forum.

 GP update
- f1.gpupdate.net, Site with fresh news from Formula 1

Planet F1
 - planetf1, another site with many different articles, news and statistics. Biased toward British teams, but anyway good read.

Gurney flap
 - gurneyflap.com, Great history site. You can learn a lot from this site. Pictures, cars and many many more. Great.

4mula1
-
4ormula1 is a database of Formula 1 history and statistics of drivers, teams, grand prix, and all results since 1950

Racecar engineering
-Racecar Engineering, an online magazine with a lot to learn from, a lot of technical information’s and explanations

FIA
 - fia.com, La Fédération Internationale de l'Automobile, representing the interests of motoring organisations and motor car users. Head organisation and ruler in auto sport.

Wikipedia
 - wikipedia.org, I don’t believe that I have to tell you anything about this site. It’s not about Formula 1 technology, but you can learn a lot about that too.

Sutton Images

grandprix photo

Carbibles
 - carbibles.com, a great site for normal car users. Here you can find explanations of almost everything about your car and how it works. Technical reviews and explanations of some in-car gadgets.

Dare To Be Different
- Daretobedifferent.org Susie Wolff and UK governing body of UK motorsport have joined forces to launch Dare To Be Different, a high-profile new initiative which is about increasing female participation, not just on the track but in all aspects of the sport.