stroker damper

Elastomer type dampers are tuned to a specific frequency. This frequency is determined by the 4th order on a V8 as that is the firing frequency. This frequency is the resonant frequency of the "system". Based on crankshaft stiffness and inertia, rotating and reciprocating inertia, piston / rod mass, and cylinder pressure through 720 degrees of rotation. This is modeled as a spring mass system for analysis and the cylinder pressure is used as the forcing function for the model. The problem is that most have no idea what the resonant frequency of the system is once you modify from stock components. Under tuned dampers will drive torsional amplitude higher into the engine operating range and can fatigue the crankshaft. Overturned dampers will drive the torsional amplitude into the lower engine operating range. A fluid damper is not tuned to a specific frequency. They work over a larger RPM range. The ATI damper is an elastomer damper but utilizes o rings that allow the inertia ring to slide within the casing causing friction damping. Friction damping has a high damping coefficient, and the sliding inertia ring will work over a larger frequency range. The o rings do require replacement periodically due to wear. 65'