Automotive Front Wheel Drive or Rear Wheel Drive has higher maximum slip ratio?

[calvinyeh]

The graph is relationship between longitudinal force and slip ratio under the conditions of 0 longitudinal acceleration and flat road(0 angle of inclination). Which line represent FWD or RWD? Does FWD or RWD have higher maximum slip ratio?

 

[Ranger Mike]

too general a question - there are rear wheel front engine vehicles
there are rear whee rear engine vehicles
there are front wheel drive front engine vehicles and the one i really like is
Front wheel drive rear engine vehicle
Buckminster Fuller ( who should have stuck with geodesic domes) introduced the
Dymaxion Chronofile ... i can't make this stuff up!

all with different handling characteristics ..slip ration being one , aspect two dimensional

 

[calvinyeh]

In this case they are both front engine

 

[Ranger Mike]

Ok , let us think about this. I assume the chart is for the front tires, correct? Both front engines. which will be able to provide more traction when cornering and why? You have the same forces ( gravity) at static. Why will one be able to handle the straight line momentum better when in a turn? why is this? Both are same tire width, diameter and compound.

The chart is a nice chart but it is just that..a nice chart. there are many many posts relating to tire slip angle on this very mechanical eng forum..suggest you do a search and read upon these.

 

[calvinyeh]

From what I have found, generally FWD vehicles have better traction because the weight of the engine and transmission are over the front wheels. This means better traction in snow and rain than RWD. But RWD has better performance when turning. So does it mean FWD will have a higher maximum slip ratio(before vehicle start slipping) which refers to line 1 in the graph?

 

[jack action]

So does it mean FWD will have a higher maximum slip ratio(before vehicle start slipping) which refers to line 1 in the graph?

The graph you shown is related to a tire, regardless of where it is mounted.

The two cases shown on the graph have both the same maximum slip ratio: 1. When the slip ratio is not equal to zero, the tire is slipping. Slip is necessary to create friction, and thus a friction force (Longitudinal force on the graph). The graph shown relates to the concept of static & kinetic friction like this:

The friction force increases linearly in the 'static' region (close to 0 slip); The peak region on your graph relates to the region where it switches from static to kinetic friction. It then stabilizes at a lower constant force at slip ratio = 1.

The difference between the two cases is most likely the normal force acting on the tire. Whether it is RWD or FWD is irrelevant.