Dangers of lightening flywheels....

Been sent a link showing what happened when a flywheel let go in a calibra....

Linky

Yep they sure need doing right.

Sobering.

Lol can gaurantee at least one if not more of the following statements are true.

1 - too much material has been removed relative to the density of the flywheel.

2 - the lightened flywheel had literally some weight lobed of the back of it in a straight line.

3 - after cutting it has not been rebalanced or initially setup correctly on the laithe to start with.

4 - the engine was being reved beyond factory specification on a continual basis.

5 - was using a paddle style clutch, you know the type consisting of 3 or 4 pucks instead of a progressive complete circle with expansion gaps.

Agreed /\

The best, safest and most consistent way to lighten the flywheel is to completely remanufacture it out of a lighter (and ideally) stronger material.

Not sure the OE one is made of, but I bought one remade from Cromoly and weighs 9lbs. You can get fidanza ones made of alloy that weigh 6lbs, but that's a bridge too far imo and I'm not keen on the idea of mounting steel friction plates onto alloy. I'd rather it was one peice. Takes another failure point out of the equation.