Lighter front springs
Stiffer front springs
Lighter rear springs
Stiffer rear springs
Note that the shock collar (upper spring limiter) should only be used to set the car’s ride height, not to change the stiffness of the spring. If you want to change the spring stiffness, you need to change the spring itself.
“Low frequency” springs have a higher coil count and less progressive feel. They reduce chassis oscillation on rough surfaces, improving overall stability, grip, and corner speed.