Monthly Archives: June 2013

Hydraulic Clutch Master Cylinder

The hydraulic clutch master cylinder used on the 2002-2006 Acura RSX, 2002-2015 Honda Civic Si and 2004-2008 Acura TSX have a feedback plate which is known to fail when installing any performance clutch that has a higher clamp load over the factory clutch. ACT has researched this problem and recommends replacement of the factory Honda/Acura hydraulic clutch master cylinders previously mentioned with a clutch master cylinder from a 2001-2005 Honda Civic (Honda Part Number 46920-S5A-G06). This hydraulic clutch master cylinder is a direct replacement designed without the feedback plate and can be installed with minimal modifications.

If you have any questions please feel free to contact our technical service department....

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 engaged, and 2) burst rattle...