[Britwrench]

The "lightweight" flywheel for the 968 is merely a single mass version. Porsche AG sent out a bulletin when these vehicles were current advising that the flywheel should be replaced (with the single mass part) if the car was tracked. To my knowledge there was no chip change required.

This was the same bulletin that introduced the wider balance shaft belt, because the narrow version was breaking with monotonous regularity on early 968 models.

For a street driven 924S, I can't see any advantage of a lightweight flywheel.