The weight (actually the mass) of the flywheel does not matter. The inertia of the flywheel is the important thing. The further the mass is from the centre the greater the contribution to the inertia. Two flywheels of the same mass can have very different rotational inertia. A flywheelwith most of it’s mass near the rim will have a greater rotational inertia than one with most of the mass near the centre.
For reference a lightweight flywheel is about 8.5Kg. Pics attached show how mass is positioned affects rotational inertia.
Also is flywheel for 28oz balance or neutral balance?
Southern GT do a steel flywheel and AP clutch setup for ZFQ.
I got it from a very trusted source. The query was only made last night when a buddy of mine who builds hot rodded Mustangs stopped by last night and commented that it was quite a bit heavier than the flywheels he uses on his 900+ hp monsters. I had no reason to doubt my supplier but was curious generally speaking.
Thanks again to all.
Wishing you all a good weekend.