Does it do much of a difference?

 

i want to say it's 3 or 4lbs lighter than the GSR. if you want a light flywheel the fidanza or exedy would be my choice at 7.5 and 9.5lbs versus 18lb for a GSR or 15? for ITR, it's either 15 or 12 but i'm thinking 15

 

As mentioned, the Fidanza would be my choice. There simply won't be enough of a difference with the ITR flywheel to justify the cost and the labour. The Clutchmasters / Fidanza (they're the same unit, so pick whichever you find cheaper) is a terrific choice and a great deal.