View single post by atgparker
 Posted: 10-23-2013 03:47 am
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Joined: 06-23-2013
Location: Mission Viejo, California USA
Posts: 78
Hi Frank,
I nabbed a Flywheel two weeks ago that was lightened and blanchard ground in the area of the clutch disk. The weight was removed from the engine side where approximately 3 pounds were turned into chips beneath the area where the ring gear is pressed on. The depth of cut was tangent to the as cast surface and then the removal of cast iron proceeded to venture up toward the ring gears mounting surface and flange. But enough material was left so that the ring gears press fit is not compromised. So the OEM flywheel is 20.4 pounds and the one I have is 17 pounds. The actual weights are not the key though. It really is were the mass is removed that matters in that the radius of gyration is what you want to be making smaller to attain the most effect in lightening a flywheel. So this effort was about an 18% reduction in rotational mass and from the brief driving stints for before and after equating to less than 200 miles in each case I can tell you the car seems quicker in first and second gear and the 1-2 and 2-3 gear changes seem more effortless in both up shifting and down shifting. In fact the engine braking and acceleration seem a bit faster from what I remember with the OEM flywheel. Basically the flywheel is there to smooth out the gear changes and smooth out the engines tolerances that make for imbalanced rotating components. With a smaller radius of gyration for a given application the car will speed up and slow down faster because the energy that is not in the fly wheel is transferred to propelling the chassis of the car down the road where the engine has good mechanical advantage over the chassis weight. That is were the final drive axel ratio comes into play as do the lower gears in the transmission. Thus for an 18% reduction like I have done the lower gears are were the effect seems the most.