Below is a chart that compares the nozzle flow using the three most commonly used pumps by methanol injection companies. This chart is intended to show you how as nozzle size is increased the pressure of the system decreases.
On the nozzle pressure chart, the dashed line on the 250psi pump shows how increasing the adjuster on the built in by pass effects pressure. Most pumps have this built in, but as you can see, it will only effect the output on nozzle sizes 3 and smaller.
The 150psi and 250psi pumps both flow 1gpm and the 220psi flows at 1.8gpm.