Hi all,
Thank you for your kindly reply.
I think that heavy flywheel does not have necessity in light weight Seven.
Heavy inertia makes easy start for gran mama who drive the normal passenger car.
If light FW put on to the normal car, it is very difficult to start the car for lady maybe.
But but, seven man has skill and wish more performance to the motor.
A heavy flywheel also has a risk of making a crack in the end web
( FW side No8) of a crankshaft.
In high rev,Crankshaft is little bit bend then heavy FW makes more stress to the corner(fillet) of No8 web and main journal.
As you know,Xflow has Cast crank, so I think light weight FW is good for crank health and me 😬.
Moreover, since there is little inertia, I think that a gear shift becomes easy.
However, as you taught (thanks everyone ), the problem of a ring gear and a friction should be solved.
I should be ask the Dave bean such about risk.
Regards