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      06-08-2020, 07:07 PM   #159
dparm
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Quote:
Originally Posted by rhyary View Post
I don't. But I can create it if you give me the formula

It's a little tricky, but here goes. Credit goes to Precision AutoResearch for providing these in a seminar a few years ago.



Understeer = (WheelAngle-RadiusAngle)/LatG

The output is in "deg/g". RadiusAngle is measured in degrees, and LatG is measured in g. A negative value indicates oversteer and a positive value indicates understeer.



As you can see, you have to do two nested formulas:


Wheel angle = Steer/SRatio

The output is in degrees. SRatio is the steering rack ratio. A negative value indicates left and positive value indicates right. The wheel angle is telling you how far the front wheels are turned for any steering wheel input.



Radius angle = 57.3*(wheelbase/12)/CornerRadius

This is also called the Ackerman angle. The output is in degrees. Wheelbase units are INCHES and corner radius units are FEET. Negative values are left, positive values are right. This formula is telling us the nominal angle the front wheels have to be turned for a given radius.
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