hello everybody .
I want to ask if the flywheel balancing is necessary ?
my motor is balancing with the flywheel too but i want to replace the flywheel and the clutch(wrong buy )but i don't want to open a brand new motor.
You believe is worth the money?
the motor is a semi bridge semi pport with s4 rotors (scalloping and lightening ...)and im shooting for 600whp

 

I had my flywheel and clutch balanced together. Assuming your engine is balanced it cant hurt.

 

i had my rotating assy balanced when I rebuilt my motor. I've recently needed a new clutch....literally bought a brand new act clutch and flywheel with counter balance, replaced the OS giken unit without a problem, literally bolted the new clutch and fly out the box, drives like a dream.
You won't have any issues

 

You may have to address the lighter modified rotors and have the whole rotating assembly balanced.
The only guy I can think of around your area is a guy named: hIGGI.(member)
If you message him see if he can give you some info on your problem.