[Supras] Lightweight flywheel+balancing

[berniek at technicaldevelop.com]

While not as light as an aluminum flywheel, I got a chrome-moly flywheel from AutoCom.  It a lot lighter than the cast iron stocker, and much stronger.  The price was right, too, about half the cost of aluminum.  It still needs to be installed as part of my JDM rebuild, now over a year old due to work considerations.

When the inertia of the pressure plate is considered, the difference in total angular inertia of the flywheel and clutch combination will not be that much different than with use of an aluminum flywheel.

Just a suggestion:  If you have a lathe, make up a ring which fits the center hole of the new flywheel and a small ball bearing in the center.  If the ball bearing is sealed, take out the seals and grease, and put clean oil in the bearing to minimize drag.  Put the ring and ball bearing in, put a shaft in the ball bearing, and stick the other end of the shaft in a vise.  The heavy side of the flywheel will roll to the bottom.  With a Dremel tool, you can remove material from the heavy side to the point where you can make the flywheel stop at any point, so its balanced.  Then bolt the pressure plate on, and repeat the process with it.  Punch mark them so they will go together during installation the same way.  

There is a way to do balancing in the car as well, which I did when putting an aluminum flywheel in my Chevy powered Firebird.  Run the engine at the speed where the vibration is worst to get an idea of the vibration magnitude.  Then take the access cover off the bell housing, take out one pressure plate bolt, put a couple of washers under it, and reinstall it.  Run the engine again, and see if the vibration has gotten worse or better.  Try this with each of the pressure plate bolts in sequence until you find the one or two at which the vibration is minimized.  Then change the number of washers to obtain minimum vibration.  That worked like a charm.  At one time I believe I saw a GM bulletin describing the same procedure for balancing a Buick flex plate and torque convertor.

            BernieK