1000, is perfect, well actually 950 psi is perfect, if you go too high you will run lean. On a wet system when you spray and your bottle pressure is above 1000 you will get a richer spray from the nitrous side, but the fuel will be the same as if you were spraying below 1000 psi bottle pressure, and you will end up lean. That's no good. The 860 bottle heater has an adjustable sensor. You don't want too much more then 950. Hope this helps.