Originally Posted by Eli

The IC is at infinity, they never intersect.

Originally Posted by CHIZZLE

And thus, my confusion continues. Lol.

Originally Posted by Eli

You're not the only one. If i'm wrong then my car must have some special forces going on. Thats like saying if i raise my inner ball stud im actually raising roll center. From what i have learned and experienced lowering the whole link equally inside and outside lowers the roll center and raising the outside ball stud alone raises the the roll center and raising the inside ball stud alone lowers the roll center. Am i wrong????

Originally Posted by OptimumRC

Unless the camber link and lower arm are parallel then the IC goes to infinity and then the RC is on the ground surface.



I have explained how you can determine your roll center, so if you look at the image I posted earlier or google some other imagines that help illustrate this then you will be able to see for yourself that the C hub does raise the roll center.

Originally Posted by OptimumRC

Raising the inner ball stud lower the roll center and as you said raising the outside raises the ball stud does raise the roll center. However, lowering the whole link equally does RAISE the roll center.

I cannot stress how just drawing something up on a piece of paper will help make this easier to visualize and understand. Regardless if you draw it perfectly to scale, just approximating the lengths and angles is enough to see the relative comparisons.

Originally Posted by Eli

Ok well the illustration that you posted is for a SLA type suspension aka short long arm and our cars dont have that type of suspension.
I drew it out in my head, the very bottom picture, if you lower that whole upper arm it will lower the roll center by having the line intersect sooner from the lower arm center line thus lowering the roll center.

Originally Posted by OptimumRC

No, that is incorrect. The roll center is determined by extending an imaginary line from the upper camber link and the lower control arm (if you draw a line through the hinge pins) until the two intersect. This is called your instant center (IC) and is the imaginary point in which the wheel, camber link and arm rotate about. Then drawing a line from the center of the tires contact patch to the instant center, and doing this for both sides of the car and the point in which the these two lines intersect is your roll center.

When you lower the upper camber link it is essentially like drawing another parallel line under the original location and as a result the IC changes since the lines intersect sooner and thus the line from the tires contact patch is even steeper and therefore actually raises the RC slightly.

One thing to keep in mind is that this only determines the 'static' roll center, but when the chassis rolls through a turn the roll center migrates around and how much it moves is influenced by the suspension geometry.

Heres an image that I just googled that should hopefully help illustrate what I said: