Help me design my fuel system, please. :)

GotDart · Post by **GotDart** » Mon Jan 23, 2006 3:28 pm

My project engine is a Mopar 340 that is bored and stroked to 416 cubic inches. Anticipated HP is in the 475-500 range with peak torque over 500ft-lbs. I will be running 42.5lbs injectors (Lucas 009's) and have a Aeromotive A1000 pump with a A1000-6 Bypass Regulator. I also have the Aeromotive 100 micron pre pump and 10 micron after pump filters

My plan is to use -10AN braided line from the fuel cell sump to the pre pump filter. The two filters will be attached to the pump with short -10AN nipples. This will all be mounted to the chassis underneath the fuel cell. On the output side of the after pump filter I was going to reduce down to -8AN hard line and run that up to the engine compartment. That's where my plan fades away.... and I need your help.

How should I plumb the fuel rails up? Daisy chain them series, or use a Y block and feed them in parallel? What size fuel rail and what size fittings for either scenario? And is the regulator I have okay or should I have gotten one with larger inputs? Is a -6AN line sufficient for the fuel return to the fuel cell?

Now to complicate things further, suppose I want to add nitrous in the future. Would the above fuel system support an additional 200hp shot of nitrous? Would I need to use a second regulator to lower the fuel pressure for the carb-style nitrous plate to 8-10psi? Would something like the Aeromotive 13205 regulator work in this application? Or could I just get smaller fuel jets and run the nitrous plate with the same fuel pressure as the injectors?

Post by **efahl** » Mon Jan 23, 2006 4:25 pm

GotDart wrote:How should I plumb the fuel rails up? Daisy chain them series, or use a Y block and feed them in parallel? What size fuel rail and what size fittings for either scenario? And is the regulator I have okay or should I have gotten one with larger inputs? Is a -6AN line sufficient for the fuel return to the fuel cell?

Depending on how much underhood space you have, I'd start with a y-block on each end, one for the supply, the other into the regulator (the A1000 bypass should work just fine). For a Y system, a pair of -6 rails should be more than sufficient, this is the stuff I've used for the one's I've built (I've got a 6' chunk of the -10 waiting for me to build something with some real HP

).

http://www.rossmachineracing.com/extrusion.html

I would use another -8 hardline for the return, just bend a pair identically...

Would the above fuel system support an additional 200hp shot of nitrous? Would I need to use a second regulator to lower the fuel pressure for the carb-style nitrous plate to 8-10psi?

Rather than answer that, I'll suggest using MS to control a dry system, so you don't have to re-plumb the fuel, just put a spray hose up top and turn on the fuel. I've seen the dry system controller at work on a truck, turned a 10.08 at 136, so seems to work ok.

Eric

andereck · Post by **andereck** » Mon Jan 23, 2006 5:57 pm

Efahl's suggestion is good. You can do away with the return Y as the regulator has 2 inlets. The pump will be happy with the -8 run up the frame as long as you maintain the -10 inlet into it. Whether you use -6 or -8 for the return is up to you. At your power level either the parallel or series rail plumbing will work. I'd plumb it for however convenient it works out. Make sure the regulator is the last part in the chain. You can have only one return regulator in the system. If you opt for wet flow nitrous just get a high pressure jet chart from Holley/NOS and run a smaller fuel jet for the higher efi fuel pressure. Tap into the fuel system at the end of the rail for the fuel enrichment solinoid.

The system you have put together will easily support 800hp.

GotDart · Post by **GotDart** » Tue Jan 24, 2006 7:06 am

Thanks for the feedback. It's nice to know I was on the right track. Now I just need to figure out the most cost effective way to plumb it up. These AN fittings are not cheap!

The nitrous system, if I decide to use it, will be a stand-alone wet system. Depending on what calculator you use, the 009 injectors max out around 525hp at 85% duty cycle and 43psi. I don't think I could squeeze another 175hp worth of fuel out of them. If I plan the system plumbing for it now, I would just need to cap off the port where the nitrous fuel solenoid would tap in. Speaking of which... the fuel regulator has a 1/8"NPT port for a fuel pressure gauge. Could I use that port to supply the enrichment solenoid?

gielamonster · Post by **gielamonster** » Tue Jan 24, 2006 8:04 am

With a -10 rail, is there any need for a dampener? The porsche guys love spending $600+ on this setup:

http://www.lindseyracing.com/Merchant2/ ... RAILBILLET

But I just can't stomach that kind of price! I'd like to make my own, and figure I can just run the -10 rail and hope for the best. I already have an AFPR, and one AN ended hose, so I'd only need another hose and some fittings to finish the job.

The stock rail has a bad habit of springing leaks, which means porsche flambe. Mine has 160k and I don't want to push fate much further!

andereck · Post by **andereck** » Tue Jan 24, 2006 8:22 am

I wouldn't use the fuel pressure port as its very close to the regulator diaphragm and may not be the best place flow wise. I would either tap the end of the rail, or if you end up with a rail with 3/8" pipe thread get a fuel pressure tap fitting that goes from 3/8" pipe to -8 male with an 1/8" fuel pressure tap, such as sold by Moroso.

MicroSquirt.com read only forum (Jan.15,2018)

Help me design my fuel system, please. :)

Help me design my fuel system, please. :)

Re: Help me design my fuel system, please. :)