ACT Flywheel on a Nissan 350z and Infiniti G35
Nissan equips many of its newer vehicles with a dual-mass flywheel to control a portion of the engine’s torsional vibrations, which causes various types of gear rattle noises. A dual-mass flywheel exhibits unique damping characteristics that cannot be replicated with a single-mass design.
When converting from the heavy, original dual-mass flywheel to any lighter, single-mass, aftermarket flywheel, much of the original torsional damping is defeated (with a partial exception when also using a spring-centered or damped clutch disc). As can be expected, the result is an increase in gear noise. In general, the lighter the flywheel is, the louder the gear noise will be.
During testing, ACT found two types of gear noise that commonly occur when using a lightened flywheel on the 350Z or G35: 1) idle mode rattle (also called neutral rollover noise), which occurs when idling in neutral with the clutch e…
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