Unlike some cheaper regulators these are properly referenced to the manifold pressure. As the manifold pressure changes (vacuum on cruise, higher pressure under boost) the injectors are 'seeing' different pressures, but the ECU fuel maps are configured for a steady state. The vacuum take off means our fuel pressure regulators constantly adjust the fuel pressure to suit the ambient pressure inside the manifold- keeping your chosen fuel pressure secure and accurate. For those trying to get the most out of their stock 440cc injectors but using aftermarket engine management these adjustable fuel pressure regulators mean you can increase the base pressure behind the injectors. This has the same effect as fitting slightly bigger injectors as more fuel is dispensed for each opening of the injecto.
