[cnavarro]

It's questionable to put a lightweight flywheel on the engine without some sort of harmonic balancing to offset the loss of the dual mass flywheel. I have had many phone calls from individuals and shops alike with broken crankshafts, attributed to lightweight flywheels and it's bad enough that Porsche issued a TSB that use of a lightweight flywheel will void the warranty, likely due to harmonics I would imagine. It's been touched upon in this thread and I highly doubt that a reduction in mass would fix the RMS issue. Engines with multiple RMS failures are indicative of a larger problem - drooping of the crankshaft carrier in the crankcase.