Since the late 70s, Cusco has been developing the highest of quality suspension for all kinds of automobiles. So doing this for over 35 years, a long lineup of different suspension models add up, confusing the end users of what features each one comes with. We thought that this blog might clarify this a bit.
Traditional vs. Fully Threaded Type Coilovers
Cusco basically starts the lower end suspension based on its type of usage, which is regular street coilovers, emphasized on comfort. These coilovers do not require such advanced features as damper setting, all that the customer needs is some height adjustment. The Street Spec-S and Street ZERO-S units have a fixed shock absorber valving, which is set specifically for each type of vehicle model.
The Street ZERO-A, and ZERO 3S are classified as street / circuit driving since it provides a certain level of damper adjustment and also a full height adjustable system (also known as fully threaded type).
Looking at the photo on the left, imagine yourself changing the height of the vehicle for e ach type, and what effects it will have on the coilover.
If you raise the spring perch on the traditional type coilover, the spring becomes more compressed - thus increasing the spring preload rate. On the other hand, for the fully threaded type, the ride height is adjusted by turning the bottom blue bracket piece only; not even having to touch the springs at all.
The fully adjustable ride height (fully threaded) system allows the vehicle height to be changed without messing up the spring preload and stroke length. It's a bit complicated explaining this by words, so the illustration displayed here might be of some help. Basically, if there are two separate lock washer perches on the suspension casing, it is a fully adjustable ride height system. This system is more favored in terms of performance aspects since it keeps the stroke range in the optimal area of the shock travel.
The traditional design tends to be a little bit more inexpensive due to its simplicity and less parts involved.
So there you have it, this is probably the biggest difference between suspension systems that are out on the market today. Before buying, do some research and understand why some coilovers are cheaper than the other due to this typical design. But beware, there are a lot more factors to consider when purchasing a coilover.
More info on Cusco suspension coming soon.
Cusco Suspension Differences new (PDF Download 500kb)
Reference: JDM Option http://www.jdm-option.com/eng/pr_CUSCO/suspension.html