Dai Yoshihara’s Two Week Wonder, GT Channel’s Time Attack 350Z


KW Club sport rear shocks 350z
KW Clubsport rear shocks convert the 350Z to coilovers instead of the stock system that has a separate spring and shock.  This saves a bunch of weight.

For suspension, Chris Marion of KW Suspension came through with a set of KW Clubsport coilovers. The Clubsport system is designed for a person whose car is driven on both the track and street. Thus, the Clubsports have stiffer spring rates and more damping than the street oriented Variant III coilovers. The Clubsports are an exceptionally flexible and adjustable shock with independently adjustable compression and rebound damping. Having two independent damping adjusters is pretty important in setting up a car because variables such as track conditions, spring rates, the amount of unsprung weight and traction from different wheel/tire combinations can cause a great deal of variation in the correct damping required from car to car.

kw 350z clubsport front shock
KW Clubsport shock peers out from behind a wind deflector that was improvised at the track in an effort to cool the overworked front brakes.  In the upper part of the photo you can see the billet adjustable SPL Pro upper arm

The KW Clubsports are also unique because they convert the rear suspension to a coilover system, eliminating the separate spring and shock combination that the stock suspension uses. This saves quite a bit of unsprung weight and simplifies the adjustment of ride height and corner weights easily in the rear suspension. It also enables the use of common 2.5″ diameter racing springs which are available in a wide variety of lengths and weights. The Clubsports also feature front accumulators which allow for more wheel travel in a short body and full separation of the shocks oil from the gas.  Clubsports also have spherical bearing equipped upper mounts.

To give the suspension essential adjustability the front upper control arms were replaced with SPL Parts sculpture-like billet Pro Series upper arms. SPL is a company that specializes in exotic Nissan parts and they make some of the best suspension links on the market. The upper arms are machined of 6061 t6 aluminum and are fully adjustable for camber and caster using no slip shims and screw shank, high quality QA1 Endura 2000 spherical bearings. The arms are designed to be very light and stiff and use finite element analysis to optimize the design,

SPL 350Z Pro links
SPL Pro rear links give the suspension a lot of adjustability, eliminate squishy rubber and eliminate the heavy cast stock lower arm that is not needed when switching to coilovers.

In the rear, SPL Pro links were used which include a special lightweight toe link specifically for coilover conversions that replaces the heavy cast lower arm and spring seat with a lightweight tubular part. The SPL links are constructed of lightweight but strong large diameter 1.25″ tig welded thin wall chrome-moly tubing. The SPL links allow for a large adjustment range in toe and camber and replace mushy rubber bushings with high-quality spherical bearings. Unlike many cheap link manufactures, SPL uses high-quality American-made forged body chrome-moly QA1 Endura 2000 bearings with injection molded Kevlar reinforced Teflon liners. Anyone who has had the el cheapo Chinese bearings beat out of there arms in a few track sessions will appreciate this expensive but quality detail.

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