Camber tire data question

[Anvit Garg]

Hey guys:

I do not think anyone visits the TTC forums yet so here is my question re-posted:

I am trying to visualize the inside and outside tire during a turn. From what I understand, the inside tire, if cambered negatively will produce camber forces outwards, thus decreasing its lateral force capabilities, and the outside tire, if also negatively cambered, will have an enhanced lateral force capacity.

The tire data shows the camber angles it was tested at, all positive in all 3 runs, but slip angles that vary from positive to negative. Is there a way to model the inside and outside tire?

I do not think think opposite slip angles will do the trick, having trouble picturing that...

My current belief is that since we do not have a previous car to design off, that if I can understand the combined lateral force capacities, I can design a suspension that allows the tires to be in that specific setting. This should narrow my steering design as well since then I can see why I would want the inside tire to possibly camber out during a turn.

I am guessing that the aligning torque plots can be used to design the caster/KPI so that the driver is aware of what portion of the lateral force curve he/she is on. Also I can determine the responsiveness of a tire during a turn hence justify my steering rack ratios.

Please correct me if I am wrong, still new to all of this.

Edit:
quick idea, what if I took the difference between the lateral force when the slip angle is positive and negative? I could assume that is the lateral force acting in an unfavorable direction and then subtract that from the corresponding negative slip angle lateral force to "model" an inside tire during a turn.

[Anvit Garg]

Hey guys:

I do not think anyone visits the TTC forums yet so here is my question re-posted:

I am trying to visualize the inside and outside tire during a turn. From what I understand, the inside tire, if cambered negatively will produce camber forces outwards, thus decreasing its lateral force capabilities, and the outside tire, if also negatively cambered, will have an enhanced lateral force capacity.

The tire data shows the camber angles it was tested at, all positive in all 3 runs, but slip angles that vary from positive to negative. Is there a way to model the inside and outside tire?

I do not think think opposite slip angles will do the trick, having trouble picturing that...

My current belief is that since we do not have a previous car to design off, that if I can understand the combined lateral force capacities, I can design a suspension that allows the tires to be in that specific setting. This should narrow my steering design as well since then I can see why I would want the inside tire to possibly camber out during a turn.

I am guessing that the aligning torque plots can be used to design the caster/KPI so that the driver is aware of what portion of the lateral force curve he/she is on. Also I can determine the responsiveness of a tire during a turn hence justify my steering rack ratios.

Please correct me if I am wrong, still new to all of this.

Edit:
quick idea, what if I took the difference between the lateral force when the slip angle is positive and negative? I could assume that is the lateral force acting in an unfavorable direction and then subtract that from the corresponding negative slip angle lateral force to "model" an inside tire during a turn.

[Drew Price]

I think you are trying to answer the wrong question!

Try to make your outside tires not negatively cambered during the turn, since you already know that reduces the maximum possible lateral force in the 'favorable' direction that it can provide.

If you find from some compromize you can't make that happen, or choose not to, your method or some very similar thought process should work. You can just look at the segments of data only in the 'wrong' slip angle direction.

Best,
Drew