PROFESSIONAL MOTORSPORT

SIMULATION SOFTWARE

....and checking forces

Suspension kinematics are specified as a function of the axle ride height. The several parameters are specified by 5 ride height points. LapSim subsequently calculates a 2nd order equation based on these 5 points. The results of this equation are plotted as a line in the graphs.

It is not always necessary that the line goes through the specified points. This may be the case if one point is out of line. However, one should consider whether such a data point is correct.

Figure showing a front view on a vehicle with the roll centre highlighted

Roll centre height

It is the angle between the road surface and the momentary rotational point per wheel, which determines the amount of tire force which is used to support the body.

When there is no roll, the two swing arms intersect to form a 'roll centre' in the middle of the vehicle. But there is not such a thing as a centre along which the vehicle rolls.

Figure showing the side view of the rear end of a vehicle with anti-squad and anti-dive highlighted

Anti-dive and anti-lift

The anti-dive and anti-lift determines which amount of the front and rear brake force is used to support the body against pitching.

Similar to the roll centre, the amount of anti-lift of the rear axle does not influence the amount of anti-dive of the front axle and vice versa.

Figure showing the side view of the rear end of a vehicle with anti-squad and anti-dive highlighted

Anti-squad

The anti-squad value of the driven axle is determined by the angle of the movement of the wheel centre.

This contrary to anti-dive and anti-lift, which are determined by looking at the contact patch.

Individual static camber is edited in setup sheet

Printscreen of the LapSim GUI showing the Camber values

In the top figure of the suspension menu, the camber dependence on rideheight is specified.

These are the camber value of the left wheel of the axle. In the setup sheet one specifies the individual camber values.

Changing the static camber of the left (front or rear) wheel in the setup sheet, means shifting the complete figure in the plot.

Adjusting by drag and drop

Printscreen of the LapSim GUI showing the 4 suspension kinematic lines

The variables can be edited by pushing the left mouse button and drag the parameter to its new position. By clicking in the figure one can select a certain ride height position. The ride height points have to be edited in the edit boxes.

If the middle ride height position is selected, a change in a parameter will lead to a shift of the complete characteristic by the same amount.