12:05 Garage- ’70 Duster build

72bluNblu said

And yes, changing the location of the end of the steering arm can alter your toe change curve. But when you're adding caster with eccentrics you're never just changing a single spec. So, it's not a given that you're always adding bump steer by adding caster, you're not making a single change so it's not simple. It depends on ALL of the other alignment specs, in addition to the ride height. Adding negative camber can change the bump steer, lowering the car the can absolutely change the bump steer, changing the bump stop heights can change the bump steer curves because you're altering the angles on the upper and lower control arms and the steering arms by changing the travel range, etc.

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I beg to differ ...it is a given that adding caster changes the toe curve, might be minor but could be extreme. The more you add, naturually, the more it changes. Depending on the other factors that you mentioned, it may improve bump steer (if you get lucky) but if it was driving decent before (as DionR mentions) and now wanders....chances are the related change in steering arm end / tie rod end made it worse. And yes, I understand very well other factors can change the toe curve....but NONE of those changes were mentioned.

BTW, for anyone wondering, for the most part toe curve isn't effected by what type of spring....coil or torsion bar is holding up the car.

If anyone wants a lesson in what an way off toe curve feels like....add a rack & pinion with OEM spindles and flipping the steering arms side to side ....then hang on as you accelerate up and beyond 45mph. As the suspension moves up / down (rises , then settles) thru acceleration, wandering barely describes the dance you get as it feels like the steering wheel has a big delay in response and cannot keep up with corrections. After that they can go strait to ackerman class and attempt a high speed 90 degree turn.


Not sure what others want to do, but I'm turning the channel back to our regularly scheduled program.................................................................................