NZ_87_TURBO

Hi there
I was trying to adjust my RRFPR last night and the highest pressure icould summonds was 27-30 psi, now this was without the eng running or upper inlet manifold on, i was just using the fuel pump jumper plug in the eng bay,

i have replaced all my lines ( after the fuel filter) with SS braided lines and have no leaks, i think my problem may lie with the standard FPR, now dont jump to conclustions, i cut the top off with a grinder and took the spring and metal flap (attached with rubber seals) out also so it would be free flowing ( as the price of a 12mm 1.25 pitch adaptor to go in there is like $30 then i gota buy the other piece also)

i thought i would have had 37-9Psi ( i put the gauge between the RRFPR and the primary fuel rail ( diff from us spec as pusation dampiner anf FPR are inopp positions) but like i said all i could get was 27-30..
I had 20 psi hold pressure when i turnd the fuel pump off

is this right? should i have 37 odd psi or is that only at idol??

please help

WonkoTheSane

iTrader: (2)

Um.. you do realize that the point of a Fuel Pressure Regulator works by restricting fuel flow, right? Picture it like this: You have a garden hose with water flowing through it, completely unrestricted. This is what your fuel system is like when your FPR is open. Now, if you need more water pressure, you have to start restricting the line, by say, grabbing the hose and kinking it, or putting a partial block at the end of it. This is what your car is doing as you accelerate. The FPR actually gets closer to closed the more vacuum is applied to it. By doing this, the fuel pressure to the injectors is kept up, and life is happy there. If the fuel pressure regulator is allowed to run freely, then it will never build more than the fuel pump is capable of supplying to an open system..

So, just to clarify: you took apart your FPR and make it "always open", right?

RETed

First of all, why are you using a RRFPR?
Are you trying to run a turbo on a non-turbo FC?
RR = higher ratio than 1:1

Second, are you sure your RRFPR can be used by itself?
Some RRFPR's need the stock FPR to be still intact and working.


-Ted

NZ_87_TURBO

yes i made the FPR so it is allways open

im running a s4 T2,, im running a RRFPR coz im cheap and am forcing my injectors to put in more gas in an attempt to stop it leaning out and detonating.... because i have a 3" inlet and exhuast and recently blew my s4 turbo, i have now installed a S5 turbo and ported the wastegate but im still weary of overboosting (10psi+)
it is also there as i have a Stage 2 ported block ready to fit once i have confirmed this setup works ok and my eng isnt stuffed from blowing my turbo,

i dont know if it has to work with the standard FPR, im pretty sure its a stand alone unit.

note my eng was not running
I am going to kink my fuel hose tomorrow with a gauge inline befopre the RRFPR to get an idea of my max fuel pressure the walbro can provide
its model GSS342

please dont ( but really do if i have) tell me i brought the wrong model pump