Quoting Sally or Dick Taylor <tr6taylor@webtv.net>:
> I feel as Mark does in this matter of the "lighter flywheel". Once the
> clutch is engaged, the whole drive train becomes part of the flywheel
> and the effect of lightening diminishes greatly. At least so far as
> acceleration is concerned.
In speaking of rotating objects, mass isn't as important as the moment of
inertia is. The moment of inertia takes both the mass and the distribution of
the mass into account. If the flywheel could be approximated as a flat disk,
I = .5*mass*radius^2. If we really wanted some improvements, reducing the
radius would be the way to go! Of course that really wouldn't work...
So the thing is, just because something is heavy doesn't necessarily imply
that the moment of intertia is large because the radius of rotation could be
small. Relative to the radius of a flywheel, the radius of the driveshaft is
very small.
Having said that, removing the possibility of harmonic vibrations could be
benefit enough in installing a lightened flywheel (I guess depending on what
RPM the vibrations occur at). I would have to think the ligher flywheel would
also offer some performance improvement, however the performance to $ ratio
could be well debated (as it has been!)
Steven Altomare
74.5 without a light flywheel
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