Bottle Pressure truly is the key to a nitrous oxide system's performance.  In the nitrous industry, it is agreed upon that changes in nitrous pressure drastically changes performance and Horsepower increase.  A nitrous bottle changes pressure depending on the temperature of the nitrous inside the bottle.  When the nitrous oxide is warm, bottle pressure is high.  When its cold, bottle pressure is several hundred PSI lower.  Please refer to the illustration below:  More ►