GFB FX-S Bosch Fuel Pressure RegulatorIf you increase the performance of your engine, you need to ensure your fuel system can deliver the goods or you're going to have a bad day! Upgrading the fuel pump is the first step, but doing this alone will usually result in excessive fuel pressure, especially at idle. This is because the factory Bosch regulators typically don't flow enough to support larger fuel pumps, especially with turbo E85 setups that demand high fuel flow rates.?, Rather