Differences between the Fluidampr performance damper, stock tuned elastomer damper and un-damped lightweight pulley also appear on the dynamometer.
Conclusion – lighter is not always better
Comparative gains between 4,000rpm – 7,000rpm at only 150rwhp peak on a boxer engine is impressive. One can only conclude how much of an improvement the Fluidampr performance damper would make at much higher horsepower. Why did the Fluidampr, at 4.6lbs heavier than the 1.195lbs lightweight crank pulley, come out on top? “Excessive crankshaft torsional vibration robs power and accelerates component wear. You need proper mass with broad range damping to control it. The more power you add, the more you need to upgrade to a quality viscous damper for durability and optimum performance,” concludes Neyman. “Mass also determines where rotating assembly resonance points will occur. As shown during testing, without proper mass the lightweight pulley shifted a new high frequency resonance point into the operating range. Flywheel/flexplate, crankshaft, rod & piston changes can all have similar harmonic effects.”
The second advantage in favor of the Fluidampr performance damper is the concept of rotating weight. While the overall weight is 5.8lbs, because the inner inertia ring is not bonded and freely rotates, its weight is not fully felt by the crankshaft once the engine is operating. It can be calculated that the rotating weight of a viscous damper is roughly 2/3 its overall weight. Meaning at rpm, the rotational weight spinning in unison with the crankshaft feels more like 3.8lbs. That, plus broad range damping, gave it the edge over the stock tuned elastomer damper.