When we were road racing we found that nitrogen had different amounts of humidity depending on the grade and the conditions the cylinder was filled in giving us uneven tire pressures. Our solution was to run the nitrogen though an inline dryer. For the LSR car I found a dryer off a compressor from a clean room. I still need to build a small chassis with some casters to hold it, but if you want I can take a picture of it and post it tomorrow. Tony