Originally Posted by
Garage19
Simple physics, your engine will accelerate a low inertia flywheel faster than a high inertia flywheel.
true - but is it significant compared to the inertia of the rest of the drivetrain/brake discs/wheels/tyres and the mass of the car?
where a lightened flywheel helps is in response of the engine when declutched. it makes matching the engine speed with gear selection quicker.
Originally Posted by
Garage19
Another thing to bare in mind for people sayng that eg a 4 kg flywheel is best. Two different 4kg flywheels may have very different moments of inertia depending on their construction and therefore behave totally different.
good point - it very much depends where that 4 kg is.
the disadvantage of a light flywheel, as rod has found, is that it makes it very difficult to pull away smoothly at low rpm.