Flywheels

[CNHSS1]

i had an SE S12 that was approx 10.5kgs iirc (stock 14.5kgs) and the ones i had machined were 9.5kgs. It would be difficult to get a machined std ET one down much below 9kgs and it still stay in one piece!
In my opinion a 4.5kg flywheel ould be pointless on a road car. Yes it would rev more freely but on a clockwork ecu the bloody thing would forever be cutting out. Most race cars that have mega light flys, have 2000rpm tickovers for a reason.