The KW Coilover Suspension Kit
Lowering that meets your demand and high quality components that last for a long life
Unlike the traditional standard and sports suspension solutions, KW coilovers have an adjustable spring seat which allows lowering via a trapezoid shaped thread.
Another difference compared to conventional series struts is the proper suspension travel, which is achieved by using shortened coilover strut housings. Therefore, even at the maximum lowering the remaining spring travel is not affected.
The lowering of a KW coilover kit can be continuously adjusted at the front axle thanks to the 100 percent corrosion-resistant KW stainless steel strut. The dirt-resistant trapezoid threads and the long life polymide adjustment collar make the height adjustments easy even after years of use. The adjustment technology used by KW works even under spring preload. Depending on the vehicle type, the level of the lowering at the rear axle is handled either directly at the strut for McPherson struts (for example Subaru Impreza); or via the KW rear axle height adjustment at the spring retainer.
KW dampers and KW springs
A coordinated unit that provides a sporty driving experience. High-quality components, vehicle specific damper manufacturing, and damper setup with many years of experience in development of suspension kits for the international motorsports is a characteristic of the KW damper technology.
The KW coilovers, for road vehicles, are built utilizing the successful twin-tube damping principle which is often used for active regulation series suspensions. With twin-tube dampers, the piston housing (inner tube) also called rebound housing and the differential housing (outer tube) are put together.
The KW spring perch is a completely underrated component. It not only holds the helper spring and main spring at the right position, but also minimizes the vibration noise of the springs. Depending on the vehicle type and application, KW manufactures the spring perch with either a high quality aluminum alloy or a polyamide composite material. Whether made of aluminum or the composite material, which is rust resistant, the spring perch is painted in the typical KW purple which is very light weight.
The so-called helper spring is made of a high quality chrome silicon steel in flat wire design. It keeps the main spring above the polyamide spring perch under tension, no matter what level of lowering. As soon as the weight of the vehicle presses on the helper spring, all windings are pressed together - the spring "goes on block".
Polyamide intermediate ring
The intermediate ring is made of a light poyamide composite material used by KW to not only hold the springs, but also to minimize the vibration noise of the springs. Furthermore they isolate the rolling noises of the body.
Bump stop with integrated dust protection system
The dust cover prevents water and dirt particles from reaching the piston rod seal package. Depending on the manufacturer, the dust cover is made of elastomer plastic, and serves as a passive suspension element.
High strength main spring
The high strength spring made of chrome-silicon steel is vehicle specific and adjusted to the respective suspension damper in its spring rate, and multicoated for longevity. It is also called the main spring at coilovers. With brands such as KW, the spring "sits" after years just minimally.
Not only does the damper or vibration shock absorber of the KW coilover kit affect the springing behavior, but so does KW spring . The resulting kinetic energy is stored by the spring during compression and converted into heat energy from the damper.
The spring rate tells the amount of force (N) that has to act to the spring, so that it immerses by a millimeter. Simply explained: the higher the spring rate, the stiffer the spring, and the more force must act on the spring to compress it.
Linear spring rate
If a suspension spring is winded linear, the force increases in direct proportion to the compression travel. A spring rate of 70 Newton (N)/mm means that 70 N must act on the spring to compress it by one millimeter.
Progressive spring rate
At a progressive spring rate, the suspension spring consits of differently strong spring windings. When a force acts, the weak windings give up at first followed by the stronger spring windings. The same effect can also be achieved by the use of two springs placed on top of each other.
Composite collar for height adjustment
KW uses a threaded ring made of a resistant polyamide composite material with a stainless steel insert. Even if dirt particles such as brake dust or sand grains hit the polyamide collar it will not be damaged. If anodized aluminum spring perchs are used after repeated lowering adjustment friction of any contamination may cause microcracks on the anodized surface. If the unprotected aluminum threaded ring directly touches the steel or stainless-steel strut thread oxidation will occur. In the worst case, height adjustment will not be possible anymore. With the durable KW coilovers in inox-line and the used polyamide collar, this is not the case.
Stainless steel "inox-line" strut housing
with integrated shock absorber
The strut housing of KW coilovers are made of high quality stainless steel and are an investment for the entire life of the car.In all weather conditions, the stainless steel KW coilovers are 100 percent corrosion resistant, and have an unlimited life.
The functioning of lowering via the dirt-resistant trapezoid thread and the composite collar is designed for long use. During a salt spray test there was no oxidation of the KW coilover struts, so even after years, the lowering is not affected.
KW damping technology in detail
Function of KW twin-tube dampers
When a car deflects while driving, the oil which is lightly under pressure, will be displaced by the immersion of the piston rod. It flows into the outer tube through the bottom valve (compression valve) which controls the flow speed. During rebound, the oil flows from the outer tube back into the inner tube. In addition to the channels in the bottom valve, the oil also has to flow through the rebound valve located at the piston rod, to get into the piston housing.
The damper of a suspension kit converts the kinetic energy of the suspension spring into heat energy and passes it into the environment. When driving a curve, the KW coilover kit works in the curve inside of the vehicle in rebound and in the curve outside in compression damping.
What does the rebound influence?
The rebound damping directly affects the operating speed of the piston rod, rebound springing, and the expansion rate of the suspension spring. So it also determines how fast the suspension spring expands back to its original position. With the KW coilovers Variant 2 and 3, the driver can adjust the rebound via 16 precise clicks.
So the diameter of the rebound valves will be opened for a softer driving behavior and closed for a tighter setup. With the adjustable rebound of the KW coilovers, the vehicle handling and comfort can be influenced.
What does the compression damping affect?
With the KW coilovers Variant 3 it is possible to adjust the basic setup of the bottom valve via the compression adjustment in just twelve precise clicks. With the compression damping, the speed of the piston rod during immersion is controlled. It has a direct impact on the body movements and the steering behavior.
When the compression valves are opened, the compression damping is reduced and the vehicle immerses faster when steering. When the compression damping is increased, the piston rod immerses slower and the vehicle acts more stable when steering. The steering behavior gets more precise, the stronger the compression damping is adjusted.