Originally Posted by
Rod-Tarry
Its only 3.5 bar at idle if you have 2 bar of boost it will rise to 5.5bar that's what im trying to say. Stu explains it better in his articles
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So you have the rate at 3 bar from Bosch & you run 5.5bar it will be vastly different.
I understand what you mean, but it's not correct. The fuel pressure regulator has a hose connected to the plenum to increase/decrease the fuel pressure based on the pressure in the plenum. The reason for that is to keep a constant pressure difference over the injectors of 3.5 bar. If you run 2 bar boost the fuel pressure goes to 5.5 barg, but the pressure difference over the injectors is still 3.5 bar (5.5 - 2.0 = 3.5 bar).