[DennisAN]

Most cars locate a "harmonic balancer" on the front of the engine, built into the fan belts/serpentine belt crank pulley. Porsche put the harmonic balancer on the other side of the engine, as part of the flywheel. Most cars can get away with a "lightweight" flywheel because the harmonic balancer stays in place. Do this to a Porsche design and you end up with no harmonic balancer at all.