There is always a lot of talk around the track and on the forums about turnbuckle position settings... i.e, long turn buckles, which position on the inside, which position on the outside, etc.. etc.. But I get the feeling that not many really understand what is happening when the angle/position/length of the camberlink/turnbuckle is changed.
What it changes, is the roll center on that end of the car. What is roll center and what does it do? Well, the roll center of a car is a spot in space where by which the car will roll around, and is the only point in the car taht stays stationary as the car rolls.
It is determined by a series of virtual lines that are created, when the upper and lower control arms meet in space on the opposite side of the car, and how that point intersecs with the center contact patch of tires (see diagram in link below).
Roll center doesn't do anything by itself, how the car roll depends on the roll center point, AND the car's center of gravity. The farther away your roll center is from your center of gravity (either a higher CG, or lower RC), the more the car will roll in a corner. If your roll center is at the same point in space AS your center of gravity, the car won't roll at ALL in a corner. The more the car rolls, the more weight is placed on the outside tires, instead of the inside tires, and usually dynamic negative camber increases.
So to lower your roll center (increase roll), you increase the angle of your upper control link/turnbuckles (less horizontal, more vertical) which means a higher position on the outside and/or lower position on the inside.
My question to those in the know, is does more roll work in offroad, like it does in onroad? And that is, "more roll will add traction at that end of the car, but it will increase the time it takes for the car to change direction".
A great reference for roll center, (with great pictures), is here:
http://www.rc-truckncar-tuning.com/roll-center.html
My intention is to help people understand what it is they are actually doing, when they change their upper camber link adjustment settings.
Discussions?