Front Suspension Pivot Dimensions

[Flieger]

So, over the weekend, for fun, I wrote a program that could simulate the kinematics of the 911 front suspension. The values for effective spring rate make sense, but I need to confirm the dimensions I used for the suspension pivots.

I have it as the top strut pivot 6.5 inches further outboard from the torsion bar axis when looking directly downwards. Then the top strut pivot is 3.5 inches forward of the ball joint. Finally, the top strut pivot is 22.5 inches above the torsion bar axis.

Now the the accuracy of these measurements is not terribly critcial if all one wants to see is trends, but I cannot see how the caster angle can come out to be positive (positive trail, the stabilizing, self-return steering input) when the strut is angled the other way.

Can anyone help me out here? I can post some graphs in the coming days between class work if I can confirm the measurements.

I am 165+ miles of driving away from my 911, otherwise I would measure it.

My goal in this was to show that adding wheel spacers or larger offset wheels has little effect on the effective spring rate for a strut suspension.

[Flieger]

Nevermind, I had the measurement clarified. It is the opposite, top strut mount behind the ball joint on a ->1989 911, which makes much more sense.