If you experience "breakdowns" suspension spring is too soft. In such situations, the drivers become unstable in control. Ideally, the spring force must be equal to the value that prevents excessive body roll.
Stiffer springs require the cars prepared for racing. In different types of races using the same car involves the installation of springs with different stiffnessYu. Pay attention when passing any corners for body roll that, when properly selected springs should be no more than two or three degrees.
For the front and rear suspension pick spring stiffness pairs. However, it is not immediately possible to achieve the desired height of the suspension, because the spring sits and at some point may "get lost" that's really bad. This is due to lack of bearing capacity, even at full compression, but with the stiffnesss, providing the necessary height of the suspension. This is determined always easy: between the spring windings should be a gap of less than 4 mm.
Choose the springs so that when refilled the car the gap between the turns of the springs was slightly more than 6.5 mm. it is Desirable to set the soft springs, even though they will give a roll of the machine within acceptable limits. To use stiff springs, based on the opinion that they reduce the roll of the car, improving handling, as a rule, incorrect.
Check the stiffness of the spring by a product code or for applying labels or stamping paint). Also determine the stiffness of the springs using the hand pump, floor scales and measuring line in kilograms per centimeter.
On everyday scales fit a piece of wood (thickness 12 mm) square at the larger end of the spring, and the top is a spring. Then, on the upper end of the spring is placed a second piece of wood is measured length of the spring. With a press of the spring compress to a certain size (e.g. 30 mm) and take readings of the weights, thereby computing the stiffness.