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Old 02-18-2012, 06:05 AM   #42 (permalink)
Spec Jay
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Quote:
Originally Posted by ImportConvert View Post
Okay, I will explain since people are still asking and wondering about rpm and all that jazz.

When you turn the wheel allllll the way, and you turn at low speed, the rim turns--and the tire turns. The rim turns at a set speed, and so does the tire. However, the inside of the tire is pivoting/turning in a tight radius, while the outside of the tire is describing an arc, and needs to be turning much faster, as it must move to cover more ground on the outside than must the inside....except it's on the same rim, and is the same diameter as the inside of the tire...so it's NOT turning much faster. It's turning at the same speed, axially.

The problem becomes apparent with wide, sticky tires. The wider and stickier, the "worse" it becomes.

The outside of the tire cannot physically perform this action, as it is physically attached to the inside of the tire as tires are a 1-piece affair, and they are both only able to rotate axially at the same speed, yet the outside of the tire is of equal diameter to the inside and MUST! cover more ground during the sharp maneuver.

The inevitable happens. It "skips". This is what you hear and feel. The outside of the tire breaking/gaining traction to keep up with the inside of the tire.

My Z06 does it, your 370Z does it, etc. etc.

The solution is to:
Create a vehicle with narrower tires (sucks).
Create a vehicle with less articulation in the steering components and thus larger turn radius (sucks).
Create a tire that is larger on the outside than the inside in diameter (WTF?).
Not whine about a normal noise that is not indicative of anything being damaged (WIN!).



Not necessarily the whole story here. They are less pliable in the cold and so the skipping is more pronounced in cold weather. See my above post.
+1

also has to do with ackermann angles
Ackermann steering geometry - Wikipedia, the free encyclopedia
Quote:
As the steering moved, the wheels turned according to Ackermann, with the inner wheel turning further.
Since the Z's turning radius is so good the inside tire turns quite a bit more than the outside.
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