If your that worried about weight on your tires on race day...take the plastic valvestem cap off each tire...it will probably have about the same weight savings as going from regular air to dry air nitrogen.
ANd dry air nitrogen does not have the same expansion rate as regular air. Thats why we use it in airplane tires...where the temps can go from -20 to +200 in a matter of minutes.
__________________
if it's cheap & reliable, it ain't fast, if it's fast & cheap, it ain't reliable, if it's fast & reliable, it ain't cheap
