|The center hub and spring retainer is a troublesome area on the stock clutch disc and ACT beefs it up.
|You can see in this picture that the ACT hub has dual springs and the springs are much stiffer than stock. This prevents hard bottoming out and keeps the hub from pounding apart.
The ACT clutches’ HD pressure plate has a torque capacity of 455 lb/ft which should be more than enough for our intended use. It has a thicker diaphragm spring with 30% more clamping force than the stock Nissan pressure plate. One of the cool things is that the pressure ring has a reengineered fulcrum point so that the engagement travel is softer and longer. This means that the clutch has a nice and easy pedal effort and an easy to modulate engagement even though its clamp force is greatly increased.
|The pressure ring used in the ACT pressure plate is made of ductile iron which has good high temperature properties and frictional characteristics as well as abrasion resistance.
The clutch’s disc also has a lot of engineering in it to make it more durable while staying smooth and easy to drive. The discs friction material is organic. Organic means that its constitution is much like a stock clutch. The friction material consists of cellulose with chopped strands of bronze wire and Kevlar fiber held together with heat resisting phenolic resin. The organic material gives a smooth engagement and is non abrasive for long life while the wire and Kevlar act as reinforcement giving burst strength and helping with heat resistance. Bursting is when the friction material fails and shreds apart due to a lack of tensile strength. Friction material is under both shear and centrifugal load and has to have a degree of strength.
|This wavy flat spring under the friction material is called a marcel spring. It helps make clutch engagement smoother.