Originally posted by Cronic
Under racing conditions, the flywheel weight can be used to control the inertia applied to the drivetrain. For instance, if a vehicle tends to ‘bog’ upon engagement of the clutch, increasing the flywheel weight will increase the inertia needed to launch the vehicle smoothly. Too much flywheel weight may cause excessive inertia to be applied, causing the tires to spin. Reducing flywheel weight under this condition will reduce the inertia applied to the vehicle and allow smoother acceleration.
I thought that too light of a flywheel would make the tires spin more cuz the engine could rev quicker. This should help out quite a few people.