Got this from Lee Grimes

The 1150 Koni coil-over kit is a ride height adjustable system meant to give good ride and handling for the street and light track and autocross use. They are not designed, valved or sprung to be really aggressive, hardcore raced, etc. The dampers are either high quality chrome plated or yellow painted depending on the model (all to be chromed soon) that generally are based on Koni Sports but often have slightly different lengths or valvings to work with the goals of the kits.

The springs are a Koni specced unit that are normally progressive rates based on a 60mm ID bottom and 60mm or stock ID top. We are generally not publishing the spring rates because the rates are specifically selected for the kit goals and are quite a bit lighter than what many people are regularly putting on with GC and similar sleeves systems and are used for racing.

If you are looking to run high spring rates on your car, I would suggest that you go with the Koni Sport or RACE and the Ground Control package. If you are looking for a good handling improvement with a wide range of height adjustability and good ride quality in addition to handling improvement for the street with the lifetime warranty, then the Threaded Suspension Kit will be an option.