I have the nitrous express dry kit on my car and it works just fine. I have separate tune for it which is really quite simple, 100 shot is X percent (in my case roughly 13 %) of my total horsepower so that amount of fuel is added to the tune (I have 15% added). Mine is rarely used as I also have 20 plus pounds of boost for daily driving. It is true that you wouldn't want to drive around every day with the N2O tune in the car as it would be rich at wot and would be far from optimal, but it will work fine with a separate tune for the track assuming you have enough pump and injector to cover the necessary enrichment.