Quote:
Originally Posted by KnifeEdge_2K1
hvnt read everything but there's one thing i wanna point out about toe
your description of toe in vs out for stability isnt exactly correct.
toe out is a technically more stable setup because when one tire loses traction, the vector the grippy tire has carves a turn which shifts weight back towards the tire which originally lost traction. Imagine this, your car is setup toe out and you're driving in the rain. Your right front tire hits a patch of oil and loses traction, since the left front tire now has more grip and is arcing left, the car initiates a slight left turn. This turn shifts weight to the right side of the car increasing the grip of the right tire, thus stabilizing itself.
the above condition only applies to the front wheels. toe in is a technically more stable setup for the rear wheels (especially so for rwd vehicles as this is one of the easier ways to prevent excessive power oversteer)
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This is much too simplistic; it takes computer programs of very complicated formula to simulate real suspension and tire action. For example in this case senario when the right wheel losses traction the forward force of the left wheel can easily initiate a right hand turn that supposedly relieves more weight from the right wheel losing more traction.
You can see this on a force diagram of the contact patch. There will be a large forward thrust and a small lateral thrust. The forward thrust pushes ahead far more than side force causing the chassis to rotate right, just not quite as much as it would if the toe was zero. And what about the effects of caster? And camber, both from caster and static camber?
Even if the left wheel did cause a shift to the left there's no guarantee that shifting weight will increase traction on the right. If traction was lost why would it regain? Nor stabilizing anything. I've written and been in charge of writing programs for suspension systems and believe me its not that easy. We have changed just very tiny things that made huge changes in handling dynamics.
The best street thing to do is to work on minimizing understeer and oversteer at each end of the car with toe and then try to balance front and rear with minimum antisway bars. If you change thrust, springs, ride height, etc you have to do it again.
Our testing with our Fit which we track regularly is zero toe at the front and 1 mm left side and 1.5 mm right side toe-in rear with our driver, drive system, wheels, tires, springs, shocks, suspension geometry, and only small rear antisway bar (none front). Change just one of those items and we have to redo the whole system.
Since you don't have ours you'd have to do it anyway.