The preceding paragraphs should help you understand why. The length of the bottom links are dependent on the roll steer and traction characteristics desired by the chassis tuner. For most track conditions, bottom links 2 shorter than the upper links work well. You should use the information in this article to determine the correct link lengths for your application. As a result, the springs and shocks are compressed from both ends at once and the suspension becomes very stiff.
Indexing can improve driveability by keeping the race car flat in the corners.
However, indexing can cause the rear suspension to be too harsh on rough race tracks. When selecting springs for your 4-link, you should keep in mind the effect that indexing has on suspension stiffness. The operation of the springrod is simple. During acceleration the springrod compresses and allows the right rear tire to move forward. This movement steers the rear axle to the inside of the track and tightens the race car.