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JDS
07-12-2010, 07:01 PM
I have a few general questions about suspension anti's. Referring to pages 617-620 of RCVD, all of the anti features are assumed to be positive and therefore always working in such a way as to reduce pitch deflections (paraphrasing Milliken)

So for example, front anti-dive is drawn as having the SVIC height above the wheel center and behind the front wheel (figures 17.12b and 17.13). So am I correct to assume that if the SVIC height were below the wheel center in front of the front wheel, that I could use the same calculation to calculate anti-dive?

What if the SVIC is above the wheel center, but in FRONT of the wheel? Does the same calculation apply, only the result would be pro-dive?

Now, what if the SVIC is very close to the same height as the wheel center, and as the wheel center moves up under compression, the angle theta becomes smaller, and then zero, and then increases again? Does mean the suspension will start with anti-dive under compression and reduce to no anti, and then begin to have pro-dive?

These questions apply to any other anti-feature as well of course, just changing the directions and angles as needed.

Thanks in advance.

Pennyman
07-13-2010, 06:26 PM
In my opinion, Anti's are very similar to the relationship between elastic and geometric weight transfer in front view.

I don't have the Milliken book in front of me right now, but If I was going to analyze anti dive, I would probably make a longitudinal weight transfer spreadsheet that took the height of the SVIC, the braking force vector (both the longitudinal and vertical component) at the tire and calculated the component of that force vector through the SVIC (basically the anti percentage) for incremented pitch angles. At that point it's just a statics problem isn't it?