Flywheels (Was:Re: RS2 turbocharger)

[Nate Stuart]

gerard wrote:

>>Just curious, I may be pulling my tranny to have a pin
>>installed in my flywheel so I can experiment with
>>different ignitions.  I have the NG flywheel in right
>>now, how does it compare in regards to weight?  I know
>>some people have just milled some of the surface off
>>to reduce mass.  I think I might have to do that
>>anyways for the correct pin placement.  Any thoughts?
>>
>
>I'd be interested in this information as well. I have a MC-1 flywheel
>sitting on the garage floor. I believe it is alot heavy than the MC-2
>and/or 3B flywheel. I also heard that lightening the flywheel might give
>some adverse effects such as loss of low end torque/grunt and if
>lightened too much it might lead to the same thing that happens on some
>Opel/Vauxhall engines. The little Opels over here are quite powerful in
>the engine size class and very torquey indeed, but the only hassle I've
>noticed and heard of is that the little motor seems to rev up when you
>did the clutch in making for a somewhat uncomfortable ride at times (not
>being able to get into the next gear sweetly). Seems like they just spin
>with nothing to pull the revs down (I'm not talking 1000s of rpm here,
>just a few hundred or so).
>
>So if I was to lighten the flywheel where would I remove weight from and
>how much would be a good amount off the MC-1 flywheel?
>

That sounds awfully backwards to me. A hevier flywheel will 'contain'
more energy, and take longer for that energy to be bled off by the
compressions in the cylinders and frictions in in the engine. A lighter
flywheel can 'contain' less energy, and bleeds it off much sooner, so
the revs drop faster.

Spin a 50 pound tire on a hub and stop it with your hand, then spin a
bicycle tire and stop it in the same fasion, you'll get the idea. In
generall a lighter flywheel will get the revs up and down quicker at the
loss of 'smoothness' where the heavier ones will take longer to rev up
and to drop revs, but they smoothen out (slow down) rapid changes in torque.

Hmm, hope I got some of that right.....
-Nate
'89 90tq
www.newtsplace.com/90tq