ayousef

Well, no matter how basic this sounds it does complicate my small brain.


talking about a Paxton 3-way fuel pressure regulator.

Scenario:


- Bosch pump, pumping fuel through the LEFT side of the regulator.

- Fuel output is on the RIGHT side of the regulator (FP gauge attached)

- Return is in the bottom


Will I be able to maintain "say" 60PSI on the output (right) side of the regulator at idle, cruise, WOT (given the pump has enough output to begin with?)

Dont ask me why im doing this, thats a whole story itself.

C5Fire

Yes, you will stay at 60psi given the fuel pump is big enough and the vacuum line is not hooked up.

ayousef

You agreed to my point where I mentioned that the HOT rails are the main reason the fuel tends to heat with an external pump and return system.

This is when I thought of this, ill have all the feed and return lines hooked up BEFORE they reach the fuel rail, I want the pressure getting into the rail to be controlled pre-rail.

so ill be running the big pump, which fill feed fuel to the left side of the fuel regulator, right side (which is the regulators output) will be the feed for the rails, and of course a return line from the bottom of the regulator.

This way, IF i am correct the pressure should be maintained at 60PSI at the rails without causing that heating issue, or at least to a MUCH lesser extent.

C5Fire

That will help a little but now you have turned your fuel system into a dead head system. That type of system lowers the amount of power you will be able to support. What pump or pumps are you trying to use? You will want the regulator mounted under the hood after the rails for best performance of the system.

ayousef

Well since you asked, let me tell you a little more on what im doing:

Im running both the stock Z06 system, which utilizes an intant walbro, tested up to 700-750RWHP using on a Boost-a-pump, kinda freaky though.

What im adding to the equation is a Bosch 455 that will be on standby and activate under boost, this is how the system is set-up.

bosch pump sucks fuel from a opening behind the main tank, passes through the left side of the regulator, pressurizes the right side to "said" PSI by retuning the excess fuel back to the tank through the bottom of the regulator, then simple a check valve on both the stock and big pump feed lines, just before they Y-together and hit the rails.

This way ill be able to run the stock pump under 2PSI of boost (boost switch activation threshold) and have the big pump take over after that. For reference the big pump also has a boost a pump hooked onto it at full voltage (17volts) at any level above 4PSI.

Base pressure will be 60PSI but boost referenced on the big pump's side. Also if the big pump looses a decent amount of pressure the check valve on the stock feed would open up and help with fueling.

If this design can do 800RWHP on a TT setup ill be more than happy. At least I know Andy@AAcorvette has tested the system however with the regulator after the rails (just as you mentioned) to 890RWHP on a SCéd vette.

I guess ill have to find out, what are you're comments? Besides asking me why I hooked it up this way, because I ran into so many problems trying to get it done the other way.

C5Fire

I've done a fuel system just like that on my 98 C5. Here is a quick drawing of the set up. The main reason to leave the factory fuel system intact is to keep the jet siphon pump fuctioning in the passenger side tank.

onfire

iTrader: (17)

That's a great way to plumb a high hp system.

What the OP is talking about is placing the regulator before the rails which is a bad way to do it since it does not compensate for the pressure drop across the fuel rails, injectors, etc,,,,

ayousef

how does the factory intake pump do it ?

its regulated in the tank, and the feed line is maintained at 58PSI, and people ave tested this single walbro pump with a BAP to 750RWHP, pressure did drop to 53PSI at max hp, but you get the picture.

ayousef

PS. although its regulated before the rails, FP sensor would be at the rails, so it will be adjusted according to the FP reading at the rails.

And under WOT if the out-put falls below set fuel pressure the fuel regulator SHOULD adjust and compensate, not to mention it will be boost referenced just to make sure FP goes up and now down.

C5Fire

97-98 vettes - Regulator mounted on the rail
99-mid 03 vettes - Regulator in the fuel filter
04 - present vettes - Regulator in the tank

onfire

iTrader: (17)

Not saying it won't work....it will...I ran 650rwhp through a single walbro + BAP with a boost referenced regulator that was located at the tank (get your head around that goofy set-up) through a t400 trans.

It worked, but was not optimum...and am not using that type sytem for +1000rwhp now.

The regulator location that you will be using will increase the fuel pressure based on boost if you reference it to the manifold, BUT will not correct for pressure drop across the rails/injectors...it physically can not since it is placed prior to the rails...

It will work...just not optimum.