I’d be lying if I said I knew how this really worked, but I’ve been generally thinking about smoothing out the engine a little after the balance shafts were removed. Turns out this doesn’t really (only marginally) improves engine smoothness, most of it is for the smoothness of the internals.
This article discusses harmonic dampers, but according to forum guys that have seen failures in this motor, a harmonic damper is a must. Based on their advertisements, the Fluidampr reduces wear on main bearings and timing gear, allows for more accurate valvetrain operation, and lowers the risk of a crank failure. “Normal stock dampers wear out and engine performance upgrades increase naturally occurring harmful crankshaft torsional vibrations. Install a Fluidampr viscous damper to reduce wear on the main bearings and timing gear, achieve more accurate valvetrain operation and lower the risk of crank failure. Unlike rubber based dampers, Fluidampr automatically adapts to any engine modifications and constantly self-tunes in real time to protect across the entire RPM range. Features precision machined and computer balanced components that never need to be tuned or rebuilt.” – from STM.
I thought these were kind of a “VW” or “Euro” mod, but apparently it works for all cars, so better late than never for me to add this part.