Wow, I started this post as a simple, Cal-Tracks DO NOT change the IC. But it obviously became much more. Hopefully this helps explain things further.

As for the Cal-Track changing IC issue. The thing that I think is being missed is the fact that all of the forces still go through one single point (per side) on a cal-track.

Concider this. If you made the lower portion of a ladder bar bolt to the upper bar in an adjustible fashion, would you be changing the IC? No of course not. It would just be an adjustible brace on a ladder bar.

The IC is defined as a central point (actual or theoretical) where the forces are applied on the chassis. With one single point of rotation on a spring/cal-track, any modifications you do to that spring, or behind that point of attachment have no effect on the IC.

Cal-tracks appear to have the same type of adjustment as a 4-link, but the difference is that the 4-link applies the force of both bars directly to the chassis, while the forces from the adjusted caltracks still go through the same single front spring bolt regardless of bar location.

Hope that clears that up.

As for "squat". Body rotation happens because of two distinctly different reasons.

1) The first reason has absolutely nothing to do with suspension points, 4-links, cal-tracks, or any of the like. The first one is basic physics. As the car accelerates, there is a weight shift from front to rear. This is because of inertia. The car's mass resists the acceleration. If you remember your old high school science. "An object in motion tends to stay in motion. An object at rest, tends to stay at rest."

Because of this "wanting to stay at rest" there is weight shifted to the rear tires. You can all feel this when you launch your cars. That force you feel during launch on your body, is your body weight being applied towards the rear of the car. You can easily "feel" how weight is being transfered to the rear tires. This doesn't mean that the weight of the car is changing, it's just moving from front to rear.

Now because all of our cars have springs, that newly added weight on the rear causes the rear spring to compress more. At the same time, there is now less weight on the front, which causes the front spring to expand. Front up, rear down = rotation.

No different then putting a load of sand in your truck. Added weight causes squat. In this case, it just came from the acceleration weight transfer.

2) The second thing that causes body rotation, DOES have everything to do with suspension set up. For one minute forget everything you know about suspensions, IC's, Anti-squat lines, etc...

First things first. C.G. is center of gravity. This means that if your car was flying through space, it would rotate around this center point.

An easy example is when you throw a frisbee. Throw it right handed, left handed, underhanded, etc... any way you throw it, it always spins around it's center.

The same principal applies to a car. It always wants to rotate around it's center of gravity.

A simple thing you can do to understand how the location of force (chassis setup) effects rotation is this...

Take a pencil, pen, marker, wooden dowel, etc.. anything like that you have, and stand it on it's end on the table. Now this pencil, pen, marker, whatever you have, has a center of gravity right at it's center point (easy to visualize on an object like this.) Now if you take your finger, and "flick" it right at the base where it meets the table, what happens?

The pencil rotates, but doesn't move forward very far.

Now set the pencil up again, and "flick" it right at it's center point (vertically). what happens?

The pencil fly's forward, but with little rotation.

This is an easy way to "visualize" how changing the point where the suspension acts on the car causes body rotation. Apply the force low, and the body will rotate rearward (squat in the rear), apply the force up high, and the body will rotate forward (rise in the rear).

Now applying these forces through suspension, shocks, and a CG that moves with acceleration (because of weight shift) is a MUCH more complicated situation. But hopefully this gives a simple explination of what's going on during the launch.

Now, just because I understand what's happening during the launch, does not mean I know how to adjust suspensions! That's where someone like Monte comes in. This is one area where all of the math and engineering in the world, can't touch "been there, done that."

I for one am grateful to see guys like Monte chime in with experience.