capn

hey all

i have finally figured out how i am going to be doing my PD install using the Marren PD. but the only thing i would like to know is if i put the PD in the location that it is, will it affect its operation?

Photos courtesey of FC3sPRO.com special thanks to REted for taking the time to draw them too.

PS hopefully i didnt butcher your drawing too much ted

BDentonFC

I would think that placing it on the primary rail would be more effective. Fuel pressure regulators naturally act as a pulsation damper. The secondary houses the regulator,therefore you would want it on the primary rail where there is now no PD to damp the pressure waves that can act in each rail.

capn

im just wondering since this is a fluid system and all pressures will be the same across the board it doesnt really matter where the PD is placed right? so can someone confirm that for me?

BDentonFC

Since pressure pulsations in a fluid system like that fairly complex and I doubt too many have done the analysis to acccurately show how much differentiation is between the two rails. However, I would think that it is entirely possible that the pressure waves can be totally different due to differences in fluid turbulence as well as different locations in the rail.

capn

i mean there shouldnt be a difference, cause its basically all one rail, just with an intermediate rubber tubing. so its basiacally putting a PD in the middle of a solid rail. and its a hydraulic system and if pressures are a certain amount in one area, it should be the same everywhere else, just like braking systems. its still absorbing the bounce but the bounce is coming from two different areas.

BDentonFC

Except that a fuel system is a bit different in the pulsations it sees, I would think. Youre operating at much lower pressures and the pulses, or shockwaves, move through each rail sperately and very rapidly everytime the injectors open. The overall rail pressure, though stays relatively constant. Would it be more effective on the primary rail, possibly. Is the location on the sec. rail going to cause problems, probably not.

capn

yeah also people have done the banjo bolt mod totally ridding the system on the PD, but i think im going to go and try this as an experiment for the benifit of everyone, and then tell everyone here if its feasable. seeing that the total cost of the whole thing is about $150. its almost as cheap as buying an OEM one, but this one is rebuildable and wont leak.