MS2 and nitrous

[chevy3100truck]

A rough conversion for increasing flow within the same size tube is 2x pressure = 1.5 times flow capacity, 4x pressure = 2x flow capacity.

[A/Fuel]

Don Jackson has a handy chart to get GPM's from area and pressure for nitro, it depends on the percentage though. I have one for alcohol too, so I imagine there is one for gas. There is usually a small difference when compared to a Racepak flow meter, but's it's better than the shot in the dark.
The main thing to remember is to convert the jet size into area though.