XRAY - Model racing cars

there are four position of inner camber link.
the upper two makes the camber link parallel to lower arm.not much camber change.
the lower two make camber change more.

my question is : what is the effect of camber change?(-1degree to -1.5 degree)
less grip?
parallel camber link not much camber change more grip.

am I right?(I know the roll centre will change also, but I want to know how chamber change effect the grip/traction)

thanks!

In general it is the opposite: more camber change = more grip. What you need to look at is how much of the tyre is actually in contact with the track surface both when running in a straight line and during cornering.

Looking solely at the camber the idea is to maximise that "contact patch" so we get maximum grip from the tyres. When running in a straight line this will obviously be when we set the camber to be 0. I.e. set the length of the camber links so that the static camber is 0. During cornering this won't work however as the car will lean towards the outside of the corner! The reason it does this is that the CG is higher than the roll center and due to the forces caused by cornering will roll around the roll center to the outside.

Let's look solely at the outside rear wheel during cornering and assum the top link and arm are the same length and completely parallel. Since the chassis will roll towards the outside it is easy to see that the inneer top link mounting will, relative to the inner arm mounting, move towards the outside! If the static camber is 0 degrees (i.e. the wheel is exactly perpendicular to the track surface at rest), the the outside wheel will actually be leaning outwards (+... degrees camber) during cornering! Not good as this reduces the surface area of the tyre that has contact with the track surface when we need it the most!

This is where camber change comes in. By shortening the top link and angling the top link down we use the fact that the suspension is compressed during cornering to compensate for chassis roll and maximise the tyre contact patch.

I hope this is clear enough.