Quote:
Originally Posted by Brian Carlton
This is the fallacy that you and Mr. W will cling to, despite the fact that it is patently false.
The cornering limit of a tire has nothing to do with the torque applied to that tire. In fact, the cornering limit of a 4wd tire can be LOWER than the cornering limit of a 2wd tire because if the tire begins to spin due to the applied torque, its cornering limit, as defined by the force it can withstand laterally (lateral g force) is reduced.
All of the benefits of a driven tire occur BELOW the cornering limit where the applied torque can be useful.
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Alright I will examine your second paragraph. You say that the cornering ability of the tire has nothing to do with the torque applied to it but then say that if too much torque is applied it will lose traction. I agree with the second portion not the first. Having accelerative forces in addition to cornering forces will diminish the cornering ability
of the one tire (but not necessarily of the entire vehicle when what is happening to the other three wheels) because some accelerative force is being applied to either:
1. maintain the speed already traveled or
2. accelerate out of the corner.
If neither is true then the vehicle is by definition, losing speed, so if it is on the limit of adhesion it will soon be well under it. Unless it is being coasted down a large hill.
I will not deal with the no power applied because we seldom coast through corners and if we do it will not matter if the car is 2wd, 4wd or unpowered.
If the car applying accelerative force is 2wd then when the powered wheels are applying the accelerative force the other two are going to be well below their cornering limit and in essence, coasting.
If all four wheels are receiving power then all will be equally (theoretically) loaded and each can approach the limit of adhesion at the same time, resulting in faster corner speeds.
In a snowy situation, if a 2wd car can take a corner at 20 mph does this mean a 4wd can take it at 40? Of course not, no matter how many doofuses think so. Can a 4wd car take it at 21, 22 or 23, perhaps.
The reason doofus gets in trouble with the 4wd vehicle on snow is not because it has less cornering power than the 2wd vehicle it is because it can accelerate much better in a straight line than the 2wd vehicle thus instilling in his tiny brain the idea that it will have superior traction in all conditions and it will not be true (for the most part) when it comes to cornering or braking.