XRAY - Model racing cars

Generally speaking, softening both ends would give more traction. More grip equals more drag which equals slower speeds. If its softer it would also affect steering response because the car will roll more side to side making it feel a little sluggish when changing direction and it will shift weight front to back more when braking and accelerating.

I think softer settings would be better for a beggining driver or as a starting point when tuning your car but ultimately you want it as stiff as possible.

I don't fully agree Qwiglee. In fact a stiffer setup results in more grip overall. The problem is however that a stiffer setup will transfer all forces more directly to the wheels which means that if such a force exceeds the maximum grip level the car will loose traction.

With softer springs you trade some of the grip for a broader range of forces that the car handle without losing traction. The reason is that the softer setup allows the chassis to roll more allowing some of the force to be absorbed before it hits the tyres.

This is why, as long as the car is not breaking traction, going to a harder setup will generally work better and allow higher corner speeds. But once you start breaking traction in the corners you need to go softer to absorb some of the excess forces.