In a recent post, we told you how to make key adjustments to a drag racing clutch. Now we bring you a closer look at some recent advances in racing clutches. Check out both stories!
Earlier this year Ram introduced two interesting advances in the operation of the billet racing clutch. First, they placed a copper-alloy bushing between the clutch fingers and the clutch pivot pins. The bushings eliminate unwelcome friction between the two components and contribute lubricity to the mechanism, making disengagement much smoother. They also add longevity to the levers, pins and bushings by eradicating binding and galling.
Second, they altered the layout of the six titanium stands, which had a tendency to splay outward under centrifugal forces at high engine speeds. The splaying of the stands was first detected in slight bolt-hole elongation in the aluminum flywheels. Ram remedied this affliction by switching the stand-adjusting mechanism from the foot area near the flywheel to a position closer to the cover assembly. “The result,” commented Ram’s Pat Norcia, “has been unmistakable: the bolt holes now remain perfectly round in the flywheel and the cover assemblies slip easily over the bolts each time these clutches are dismantled.”
Until recently, OEM truck release bearings, or throw-out bearings, were adapted for drag racing use. However, they are filled with grease and inevitably contaminate the racing clutch. In 2011, Ram introduced release bearings designed specifically for the purpose of drag racing. These bearings, which are made to suit fork-style and cross-shaft-style clutch release arms, are of a double-shielded, grease-free spindle bearing design. They also use a harder tool steel contact face to eliminate wear and scarring on the clutch fingers. By substituting light oil for grease, the bearings spin up to full engine speed quickly. They also eliminate run-out.
In common with the drag racing clutch, the twin-plate street-strip clutch operates with a floater plate between the clutch discs. Twin-plate systems are available in two different forms. In one the floater plate operates with stands; in the other the floater plate operates with straps. The unit of choice for the competition-oriented street car is the stand-driven style, although the floater tends to rattle at idle. For the high-performance street car where the emphasis is on quiet operation, the strap-driven alternative is preferable.
Text by Sam Logan Photos by Moore Good Ink
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