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      06-20-2007, 05:27 AM   #13
Sparky66
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Drives: 335 E92 Coupe. Jet Black.
Join Date: Feb 2007
Location: Sydney, Australia

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Orb I understand what you are trying to say but give it rest mate !
When talking about traction on a car forum you will inadvertantly be talking about its' handling characteristics as a complete package not just a measure of one component or how much it spins its tires if I squeeze the go pedal too much. Thats why hi performance cars have launch control and traction control aids - to harness all that horsepower. Any one of these types of cars can sit there and wheel spin into a cloud of tyre smoke and/or tyre destruction but when the same car is controlled via all their handling components and a skilled driver it's like watching poetry in motion - lap after lap.
I never meant for you to get so technical with Force formulas and Newtons Law. This wasn't the objective !

All I was trying to say is that a cars handling and traction characteristics rely solely upon the performance and sum of all the cars parts and together they increase traction - i.e.. improved chassis stiffness, lower sprung vehicle weight, ideal suspension geometry to reduce polar moment of inertia, (CG) low centre of gravity, lighter unsprung weight such as in lower control arms and lower portion of shock absorber, reduced wheel/tire weight, increased width and improved rubber compound for grip aka.. "Traction". Since the tires are the only thing touching the road surface,they communicate what the rest of the cars chassis and suspension is feeding it .The less energy exerted on the tires the more they keep their ideal shape and thus provide a larger portion of contact patch with the road surface. If this is acheived then the rest is up to the tires compound and groove pattern to show off its designed for fully engineered capability. You can have the best gripping tyres in the world on your car but if it is let down by its' suspension it will not handle any better than a horse cart.

If we relied on increasing the weight of a tire/wheel to improve traction we would be in trouble as soon as we reach the first corner and all our good work would come unstuck . I could go on but I think you get the idea.

The ideal car would have a low unsprung to sprung weight ratio - take that from one mechanical engineer to another
Anything that increases weight on a car both sprung and unsprung is detrimental to its outright performance in all areas - Braking, slower acceleration, stress on the chassis, increased tire wear, greater fuel usage, reduced road holding in turns because of increased polar moment of inertia from the cars ideal centre of gravity etc... etc...

BMW build cars with 50:50 weight distribution to aid its' handling capability. The best built and balanced car chassis's concentrate all their weight right in the middle of the car (left to right and front to back) and as low as possible in relation to the suspension geometry. This reduces how far away the vehicle mass moves away from its ideal handling position and how quickly it should return when negotiating a manouvre. The longer it takes the worse the handling and traction.

Have a Good day.
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Last edited by Sparky66; 06-20-2007 at 06:10 AM.