OK right... it's quite simple.. impulse regs 101
The max flow u get with the impulse will run on CO2 or Air, whatever its orientation, horiz/vert.
If u have a horizontal then i guess u can screw in a pre-set air system like a PMI or whatever just like you could just screw in a CO2 bottle.
I have a vertcal max flo on my impulse and i have a few options. I could screw in a CO2 bottle and run that into the vert max-flo. I could screw in a pre set system and run that into the max flo, acting just like a CO2 bottle would (they are normally 800PSI, same as CO2). Or you could do what i am curently doing, have a seperate wdp AIR or whatever on the bottom, run that into the vert max flo. Set the AIR to about 700 or so, the maxy to about 180-190, fiddel with the dwel, and jobs a good-un great flat shots. Double regging like this is a bit more consistant and such like. By the way these setting are for my custom '02 Nasty Impulse, dont take for red on the stock.
If you are having max-flo problmes, or anything impulse related then drop by
The Impulse Owners Group And have a look on their forums, FAQs and documents.