DP + Boost ???
Although say 15psi will be a small % difference of nitrous flow (1000+psi) getting a pressure differentual change of 15psi on the fuel is a big difference. Run the calcs so your fuel is jetted right or kaboom
and as for the pressure effecting nitrous flow i would think that every 1lb of boost would be like -1lb to bottle pressure(in terms of how much comes out of the jet)so as long as you stay within the 900-1000lb(bottle)pressure range it should be fine.
edit: or it may act as -1lb per cylinder which would me -8lbs of bottle pressure per 1lb of boost. so you may have to jet up a little to get the same ammount of nitrous out of an equal size jet. so at 15lbs of boost it would be as if you had 120lbs less than what you actually have in your bottle. although if you have that much boost you probably dont need the extra power from the N20.

