slightly out of the box fuel distribution system concept
 

As some of you know, I have a NB engine conversion that will eventually make its way into my 91. The common fuel system remedy with this conversion is to put a NA FPR onto the NB's fuel rail, but due to the location of the flange on the 01+ fuel rail, it is a pain in the ass to make the FPR fit.

So what if I drop a NB fuel pump FPR into my fuel tank and leave the NB pulse dampener on the rail. I have the Walbro 190HP in tank to more than keep up with demand. And then I can easily modify the 01 rail for dual feed. I can even go as far as supplying the former return line with pressurized fuel from the tank, essentially creating true dual fuel feeds to the rail.

Now understand why most people who install an NB engine into an NA swap the FPR over is because they will use the stock engine management. I won't be doing that.

Feedback?

Ben

only issue i see is that people are having trouble idling larger injectors at 60psi at idle.

I agree. I do plan to go to the HR code so :dunno:

Should be fine! Good idea Ben.

you could just use an adjustable 1:1 FPR to keep the idle pressure low.

yeah, but I'd either need to run a vac line all the way to the rear, or I'd need to have two FPRs to make it work.

Or you could do what I'm doing. I have the stock 99 fuel system. I added another pickup tube to the sending unit for the nitrous systems fuel pump. Anyway, I'm gonna use a stock fuel pump with the stock regulator blowing into a pierburg. Then the stock fuel line goes to the engine bay, where it will go to a 1:1 external adjustable return style regulator mounted to the firewall. The regulator has 2 outputs so that's will fuel a dual feed rail. Then you'll need a return line. I already ran a return and mounted a pickup tube in the sending unit, so that will be my new return line.

The regulator goes after the fuel rail. (pump to fuel rail to regulator to tank). So your regulator has 2 inputs, not outputs, which are there so it's easier to install your inlet line to the regulator. Or I'm completely not understand this which is probably the case.

Yea, you didn't understand it completely. Here's the specs on the regulator I'm gonna use. Oh, and it has 3 regulated outputs, not 2. It's fuel goes in, 3 regulatded outputs , and a return.

Part Number: MAA-4305M Fuel: Gasoline/Alcohol Pressure Range (psi): 30-100 Regulator Style: Return Regulator Location: Inline Boost/Vacuum Reference Port: Yes Boost/Vacuum Rise Ratio: 1:1 Gauge Port: Yes Mounting Bracket Included: Yes Fittings Included: No Rebuildable: Yes Inlet Quantity: Single Inlet Attachment: Female threads Inlet Size: -8 AN Outlet Quantity: Three Outlet Attachment: Female threads Outlet Size: 3/8 in. NPT Return Attachment: Female threads Return Fitting Size: -8 AN Regulator Material: Aluminum Regulator Finish: Black anodized Quantity: Sold individually.


Here's a link the the regulator.
http://store.summitracing.com/partde...5&autoview=sku

how large? 550s are fine.

Ahh ok I see now. I have the same basic regulator except aeromotive.
http://www.aeromotiveinc.com/product...sub=1&prod=157

And you are going to run a fuel rail with no "return" on the rail...or make the original return a second supply/dual feed. Makes more sense than my setup where I just replaced the OEM regulator with the fancy one where all the fuel flows thru the fuel rail before entering the regulator. It would have been smarter to do what you want to do and probably easier to plumb. No fancy Y fitting needed then...hmmm. :bigtu:

It used to suck idling 550s before hi-res. Now i'm idling at 13:1, sometimes a little leaner without any issues. Y8s sequential injection helps him a little. So high-z 550 rx7 injectors can be idled in batch injection at the stock NB 60+psi fuel pressure at least as lean as 13:1 without problems.(When running hi-res)

Why do so many people seem to be idling in the 13:1 range? Seems awful rich.

For maximum power.

i was idling at like 1.2PW on 460s at 35psi.....for a good 14.7:1

Speaking of your eventual engine swap Ben, have you checked your PMs? :wavey:

w/the hydraz I idle my 550 low-z injectorz at like 1.0ms and 14.4 AFR.

no idea what my fuel pressure is.

If I lean it out anymore it "surges" "oscillates" "goes apeshit" w/e you want to call it. Apparently with the higher NB fuel pressure with 550s that flowed for than 550 out of the box MS Hi-Res won't idle them smoothly any leaner.
Lucky bastards with low fuel pressure and small injectors.

What do you idle at Y8s?

No, I get waaayyy too many of the fuckers. What did you need?

Bummer. Mine's been doing pretty well at ~ 14.5 with the 440 injectors, running HR code.