that was me:



"Info from SX re elimination of FPD when using their FPR

Hey gang:



I spoke to Rick Fenton, president of SX's North American distributor, today about their FPRs. Specifically, I called to find out whether it is necessary to retain the stock FPD when using their FPR. The website notes that the FPR also functions as a damper. There have been a few threads speculating about this subject so I thought I'd post Rick's response. For those of you that are in the market for a regulator I should also note that they sell direct to the public.



http://www.fluidcontrol.net/pages/regulators.html



Enjoy,



Chris C.





"Good Morning Chris,



Here is the information that the engineer gave us. If you have any further questions, please let me know.



Best regards,

Rick Fenton

President

FCP



Removal of OEM Fuel Pressure Dampeners can be done on fuel systems using the SX Performance Line of EFI Fuel Pressure Regulators. SX Performance EFI Regulators contain a light weight diaphragm assembly to help prevent fuel system chatter and provide pulsation dampening over a variety of frequencies. This dampening effect smoothes out pulsations created by fuel pumps and fuel injectors. Typically, the OEM pulsation dampener can still be used depending on the design and convenience of plumbing, although it is not required with the installation of the SX Performance EFI Regulator. "









http://www.fluidcontrol.net/pages/regulators.html

"

also I want to mention that you can tap the hole that the stock damper uses to accept a -6AN fitting.

First of all, that is a great drawing because I understand exactly what it represents.



It is true that a FPR will function as a FPD. But if you replace both with one FPR (leaving one rail without either), you lose the ability to cancel the fluid frequencies in that rail. That could cause fueling issues.



Also, you can't use 2 FPRs with the stock rail and line setup. The FPR goes at the end of the circuit to regulate the pressure of the entire fuel line before it which contains all 4 injectors. Put in 2 FPRs and you may get unequal pressure in the rails (unless the 1st fpr is a dummy and only acting as an FPD). Stick with the stock setup unless you plane to change the fuel rail setup.