Fuel Pressure regulator

[jamiemirror]

@ nmwisima:
I was outside to take a walk with my daughter :-)
http://www.billzilla.org/4agstock3.htm

Quote:One last important item is the small rubber pipe that goes from the inlet manifold to the fuel pressure regulator. What it does is this - When there's a high vacuum, as you get at idle, it alters the regulator so that it has a little less pressure. When you open the throttle, the manifold pressure quickly rises a little, and as a result the fuel pressure also rises a little, thus making a cheap & effective accelerator pump. The engine will work just fine without that rubber pipe though.

This is interesting explanation about "2.2 bar pressure at idle" case.

Quote:oem gZe running at 0,55 bar boost and about 2,5 bar fuel pressure at idle, right?
I use a larger pulley, STi pump (240 lit/hour) and fuel pressure regulator and run 0,86 bar boost with 3 bar f.p.

When GZE engine idles - the fuel pressure will be again 2.2 bar (because of VAC). When GZE runs 0.55 bar boost - the fuel pressure will be somewhere 3.05 bar (if we measure 2.5 bar on NA engine + boost pressure). The main ideia is to increase injector flow via fuel pressure instead of injector size. This can be done in limited (~10-15%) borders. So in described situation if we run idle at 2.5 bar instead of 2.2, NA will be 2.8 and boosted - 3.35 bar.

PS:4AGZE uses electic supercharger clutch and some electric air valves but I'm not sure about electric valve for fuel pressure regulator - I just haven't info about this regulator from GZE engine.