[Ron Sutton]

Originally Posted by Track Junky

This is great stuff right hear Ron and please correct me if I'm wrong but it is darn near impossible to find IC with all the sheet metal in the way?........which in turn makes it impossible to find static RC.
Well ... we're not trying to touch the I/C location, nor are we running the lines to intersect physically on the car.

We're doing it in software. You have to measure x, y & z of all the pivot points of the UCA's & LCA's along with locating the centers of the 4 ball joints.

If your car has the inner fenders, it can tedious work & challenging to get accurate measurements ... but it's very doable. Lance Hamilton just did it (with my guidance) on his '85 Monte Carlo, so I could work out his front suspension geometry, roll center, camber gain, etc. He had access to a drive on lift that was fairly level. That made it much easier for him.

It won't be difficult for me at all ... because I'll be sitting at home in the air conditioning. It will be tougher for you under the car.


I'm getting ready to transform the front of my stock subframe from conventional spring and shock to coil over. Maybe I should p/u another stock subframe and start from there?
I find they vary too much. Lance's was off 1/4" at one point that shot his roll center over 9" to the left. That's a big deal.


Also, when drawing the lines through the UCA & LCA's at the outside connection points of the arms are you drawing through the center of the connecting point at the top of spindle/ball joint?
No. The line goes from the center of the control arm pivot ... on the frame ... through the center of the ball joint pivot. Look at the photo below. if you decide to do this, I'll be happy to provide you with a game plan & instructions.

Maybe I missed it somewhere but now that we know how to get roll center how do we find center of gravity?

I haven't outlined how to yet. I can at some point. Maybe when we start the "General Chassis Tuning" threads ... next week.

Frankly, of the two ... RC or CG ... finding RC is way more important, because your CG is where it is. But your RC is a bigger variable ... and you can make significant tuning changes by moving the roll centers.

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