ISR Pro Series Coilovers - Nissan 240sx 89-98 After Years of Success with the Basic Coilovers ISR Performance has released a higher end line of coilovers providing better dampening control and overall performance. These are a great coilovers for the street and track use. Provides a comfortable ride while improving handling. Features: 32 Way Adjustable Dampening Mono Tube Design Spring Rate: 8K/6K Front Pillowball Upper Camber mounts.