Without a flywheel, every single fluctuation from the engine would be noticed. The gearbox and clutch would suffer and the car itself would lose speed. A solid mass flywheel, working together with a spring clutch plate works the same way as a duel mass flywheel. However, when the DMF is faulty and fails to perform, the clutch is then highly likely to break too. It is much more cost effective to convert your flywheel, as having to replace it along with your clutch would become very expensive. Vehicles that are already fitted with a flywheel conversion may also require a concentric slave cylinder, which are sold separately.