RE: flywheels

["JMazlumian" <jmazl@domain.elided>]

I received this very interesting e-mail from Jess Liao that I would like to
share with all of you interested:

> Subject: flywheels
>
> what happen is that the wheel stores energy.
> like many digesters pointed out, it is mainly used for low rpm use when
> engine torque is low (esp starting from standing still to moving).
>
> see, it takes X amount of energy to sping that massive wheel at Y rpm.
> In order to draw energy from the wheel, you release clutch and the
> friction plate starts to draw the energy away by transfer  some
> of the energy to gearbox which then drives the wheel to put your car
> in motion. Without the flywheel, you'll have to rev the engine
> significantly
> to gain enough momentum (energy)  and apply the friction plate carefully.
> The flywheel acts like a damper. If you apply the friction plate a little
> too quick, it draws energy from the wheel, if not, it gains energy from
> engine.
>
> Now, with car traveling, especially at high engine rpm. The engine
> has to accelerate with the mass and a lot energy are used to sping
> that wheel to higher rpm. Think about how much it took to move the
> 3000 lb car from standing still, then think about how much energy more
> to move the car fast. The wheel stores enormus amount of energy.
>
> This also slows down engine response because when slowing down the
> rpm, it has to work against energy already stored in flywheel too!
>
> by moreving the outer flywheel even by a bit would remove a good
> percentage
> of mass where it matters the most, thus less energy is stored and thus
> engine deals less with the flywheel and can transfer more useful energy
> to the ground.
>
> Again, if removing too much mass of flywheel, it may not store much energy
> for stop to start clutch action which make it hard to drive without
> stalling engine.
>
> I hope I ma making it simple enough to understand....
>
> Let me know if it helped.
>
> Jess
++++++++++ now my 2 cents:

Thanks for the response.  The point is: is the weight/mass of the stock
flywheel ideal for the average driver in an american road?, or can it be
compromised some, like so many other things, to provide quicker response,
without loosing "too much" streetability.  Is the same with cams, how low to
lower the car, stiffer springs, and the list goes on....
 Jorge

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