what is a fuel pressure regulator efi fuel pressure regulators job is to maintain a constant fuel pressure above the intake manifold pressure. why and when should you buy a fuel pressure regulator the installation of performance fuel injectors or a high-flow fuel pump requires the use of an aftermarket fuel pressure regulator to allow pressure adjustments while maintaining a stable base pressure. they can also be used to maximise a standard fuel systems ability to cope with minor power modifications. ideal for modified street cars with up to 800hp fuel systems using pump fuel. 1/8 npt fittings 30 70 psi base pressure adjustments 1:1 ratio aerospace-grade billet aluminium construction supplied with a mounting bracket, vacuum nipple and a gauge port blank