We are currently transitioning from a Black to a Silver finish on our coils, as such you may receive coils in either colour. We will ensure where possible to supply sets of coils in the same colour and if you are concerned about what colour you will be supplied please contact us when you order to find out what colour we have for the coils you require.

SUPERIOR TAPERED WIRE / PROGRESSIVE RATE COIL SPRING "The Intelligent Coil Spring"

There is no disputing the advantage of increasing the spring rate in a vehicle to improve vehicle stability and load carrying capacity, however, in many vehicles we are often confronted with three major considerations:

• Ride Comfort
• Shock Absorber Control
• Spring Entrapment

RIDE COMFORT is always a consideration. The spring rate must increase enough to give improvement without causing undue harshness.

SHOCK ABSORBER CONTROL - The shock absorber obviously plays a vital role in controlling a vehicle's stability. Excessive spring rate can often find shock absorbers struggling to control the vehicle (lack of rebound control).

SPRING ENTRAPMENT - When an increase in spring rate and decrease in vehicle ride height is required, spring entrapment can become a problem. Previously, the only solution is a compromise of minimal increase in spring rate and/or minimal decrease in vehicle ride height giving unsatisfactory results (suspension bottoming or not low enough).

ENTER THE SUPERIOR TAPERED WIRE / PROGRESSIVE RATE COIL SPRINGS

Progressive rate springs are the ultimate in spring design. The principle is simple. The spring rate increases when you need it (cornering, load-carrying etc.) and decreases when you don't. The science behind designing a progressive rate coil is knowing over what suspension travel and to what degree the spring rate will increase. This varies greatly between vehicles. Referring to the above 3 conditions with Superior Engineering Tapered Wire / Performance Progressive Rate Springs a substantial spring rate increase is achieved with minimal loss of ride comfort as the spring rate increases and decreases where necessary. As the spring de-rates (the spring rate decreases) the shock absorber no longer struggles for rebound control and gives improved vehicle stability.

With Superior Engineering's Tapered Wire / Progressive Rate Coil Springs, spring entrapment problems are now often solved with substantial spring rate increases and ride height decreases available.

SUPERIOR SPRINGS PERFORMANCE TAPERED WIRE / PROGRESSIVE RATE COIL SPRING
"The Intelligent Coil Spring"

Progressive Rate Design Principles

Remembering the principle, 'the fewer coils in a spring, the higher the spring rate' as the spring compresses under load the gathered coils come into contact and become inactive thus increasing the spring rate. The point at which each coil comes into contact and the rate of increase is the result of extensive research, development and testing on advanced testing equipment.

De-Rate

Superior Engineering's Tapered Wire / Progressive Rate Springs in most cases are designed around the De-rate principle, i.e.; the critical part of the suspension travel from ride height back to full suspension drop. The aim is to allow the spring rate to decrease smoothly back to the original spring rate or as close as possible.

Example:

Original Spring Rate 120lb/"
Heavy Duty Linear Spring Rate 160lb/"
Superior Engineering's Progressive Spring Rate 130lb/" to 200lb/"

Result:

The above progressive rate spring would have similar or more improved ride quality than the heavy-duty spring with a substantially higher spring rate being achieved at ride height.

Please Note: Tapered Wire / Progressive Rate Springs are not necessary for all vehicles and are only used in specific vehicles recommended by Superior Engineering Springs depending on suspension type and spring travel.

Superior Engineering's Tapered Wire / Progressive Rate Springs have the unique ability to allow many part numbers to cross-reference not only between different vehicles but also front and rear. As the load varies in all cases, the spring rate adjusts accordingly.