subject: Wheel Slip [print this page] So as we covered in our blog, Wheel Slip is The ratio of the rotational speed of a braked wheel to that of an equivalent free-rolling wheel, expressed as a percentage. The slip is equal to the speed of a braked wheel divided by the speed of an unbraked wheel, expressed as a percentage .. according to Answers.com . What this basically means is that the speed of the free-rolling wheel & the braked wheel is pretty much a ratio that is shown as a percentage. The formula is as shown :
Slip % = Speed of the braked wheel
Speed of the unbraked wheel
Do you get it? I hope so. I have to admit, it was a little difficult in words, but when I actually drew out the formula, it was a lot easier to understand; right?
There are actually two types of contact that your tires can make with the road that you just so happen to be driving on : Static Contact & Dynamic Contact.
-- Static Contact is when the tire & the road are not slipping proportional to each other. The coefficient of friction for static contact is usually higher than the coefficient for dynamic contact; which means that static contact provides a better traction percentage for your vehicle.
-- Dynamic Contact occurs when your tire is slipping in correspondence to the road. The coefficient of friction for this type of contact is lower; therefore, you have less traction .. which may not be so good when youre driving in the rain; right?
To be quite honest, Wheel Slip can only occur when the force applied to a tire is greater than the traction that is available to that specific tire. The force can be applied in one of two ways : Longitudinally or Laterally.
-- Longitudinally : this force comes from the torque thats applied to the tire by either the cars engine or brakes. This can either decelerate or accelerate your vehicle.
-- Laterally : this type of force is generated when your vehicle drives around a curve. It makes a car change direction & eventually, the tires issue lateral force when combined with the ground.
If you have Traction Control, then you shouldnt have to worry about this at all. Traction Control was designed to reduce Wheel Slip & keep a good amount of traction at the wheels that are driven when the road is covered in either water or snow. This specific Traction Control System reduces Wheel Slip by braking the actual wheel that is losing traction. This technique was designed to work at speeds that are below 35 MPH .. or 56 KM/H.
The control module monitors in the Traction Control oversees the wheel speed very closely. If in the time of acceleration the control module perceives Front Wheel Slip & the brakes arent applied, then the control module will automatically enter something called Traction Control Mode. When Wheel Slip is finally detected, Traction Control works in this order :
1. It closes the Isolation Valves that are normally open.
2. The Start pump/motor & supply volume/pressure circuits to the hydraulics in the front.
3. Open & close build & decay valves work so that they can maintain a minimum percentage of Wheel Slip & keep maximum traction.
If it were up to me & my car, Id want to have Traction Control installed on my vehicle to save my car & my Factory Original 2009 Volkswagen Routan Wheels .. but thats just me (: So be sure to visit us at OriginalWheels.com
