What is an adjustable fuel pressure regulator and how does it work?
Fuel injected engines have a regulator just before gas flows into the injectors. The regulators ensure that consistent pressure is maintained (through better atomization of the fuel spray) as gas flows into the injectors. The pressure is measured in pounds per square inch (psi). A number of companies (like TPIS) sell adjustable regulators that allow you to vary (increase or decrease) the pressure/flow of the gas there by modifying performance. There’s an adjustable screw on the regulator used to set the pressure. There are usually no marks on the regulator showing you the exact pressure setting, so it’s really hit or miss when you’re adjust it. There are a number of fuel pressure gauges (like that from NOS) which can give you a more accurate measurement. This is probably the best way to go. Before you start setting the pressure, remember to have the key in the “ON” position, but do not have the engine running. Once you have your base down (say like 49 psi) approximately 1/4 of a turn w
