This is my custom made fuel regulator with a metal diaphragm instead of a normal rubber type. It is able to withstand more than 150psi of fuel pressure (I am running at 90 psi for better fuel atomization).
The standard fuel rail adapter for running after-market fuel regulator.
The AEM fuel regulator is able to withstand up to 120psi of fuel pressure and it bolts straight up to the fuel rail = neater and less chances of leaks.
These are three different sized orifices that came with the fuel regulator. The rule for change the orifices: Bigger the orifice = less chances of fuel pressure spike (due to bigger fuel pump) but more sensitive in adjustment of fuel pressure (meaning harder to do minute adjustment)
Extracted from AEM installation manual:
"A common problem that occurs when using a fixed orifice in a “universal” regulator is that the fuel pressure cannot be effectively controlled when the fuel pump volume is significantly higher than stock. In the case of too small of a discharge orifice, there is a large pressure spike associated with rapid deceleration because the orifice cannot flow enough fuel when the diaphragm is fully deflected to the open position. This causes a momentary rich condition, which may lead to a rough idle quality until the pressure stabilizes. Conversely if the discharge orifice is too large the adjustment is difficult because the response of the fuel flow out of the orifice is too rapid which makes the adjustment screw too sensitive. The AEM regulator is packaged with three orifice sizes, .100”, .150” and .200”."
Since I am using the in-tank version of the Bosch 044 fuel pump. I had changed the orifice to .150" size (it came installed with .100" size).
The installation is quite straight forward. Bolts up just like a stock fuel regulator :)