Here is the chart showing the various fuel pump curves and the injector curves. The way to use it is as follows. Travel along from left to right on a fuel pump curve. Find the point where the pump curve crossed a given injector size curve. This is the point of maximum output and thus the x axis of the graph gives the maximum fuel pressure for that point. For example, if you follow the MR2 3S-GTE pump along till it hits the 550 cc/min injector line, you look down and find yourself at ~60 psi, or about 15-18 psi above the normal base fuel pressure of 42-45 psi. Thus, because the regulators raise fuel pressure at a 1 to 1 ratio with boost pressure, you can not safely run much more than 15 psi in a perfect world. Remember, these are lab tests, your pump could be a bit weaker or you may have a bit of pressure drop in your supply line so these numbers are not leaving any margin.
