As long as the stuff is only removed from outer edge of flywheel and it is balanced properly, lightened flywheel is actually safer than stock flywheel.
Because lightened flywheel has less mass in edges, the center (which is the area that fails) will have to endure less stresses because there is less centrifugal forces tearing it apart. Also, lightened flywheel stores less energy due lower mass and it does less damage in event the flywheel breaks.
Because my project will rev to around 8500 and stresses are quite high, I decided to get custom billet steel flywheel since the price is going to be reasonable.
Theses parts are going to form the clutch:
That Tilton pressure plate will be converted to operate single sintered three paddle disc
