Check out this fuel system

Here is a pic of one of our dedicated fuel systems.We are in the process of building one that will not have to have a battery relocated and a system for the corvettes.They should be our very soon.

This one is available now.
The system comes set up for one fuel solenoid.This system has a walboro 255 fuel pump and a aeromotive fuel regulater that can be set for high or low pressure.All parts and fitting are included to complete the install.The stock battery hold downs fasten this system in.So there is no drilling required on the car.
http://img15.echo.cx/img15/4598/fuelsystem1gy.jpg (http://www.imageshack.us)

This is the upgrade for people using 2 fuel solenoids.
http://img15.echo.cx/img15/8896/fuelsystemupgrade2mr.jpg (http://www.imageshack.us)

Dave

Of course I like it, but I have one question.....where's the vent?

Thew vent is in the cap.

That is merely an anti blow up the cell like a baloon device. Or anti suck it down like a pop can device. Or anti I can't yank this cap of my cell because its sucked down device. Those cap vents don't flow enough to support the volume of fuel that can potentially be leaving the system under a big nitrous hit.
But I still like it.

I still feel bitter about you coming out with this after I built mine! :p :D

To make myself feel better, I'm gonna ask a question. ;)

Any tips on getting the AN fittings to seal up? I have all mine around a quarter turn tight, and many of them leaked. I've been too lazy to go back and retighten, but do I have to worry about overtightening? Same with pipe threads (that have thread sealer on them), do I just crank them down until the stop leaking or?

Thanks, and I guess the info could be helpful to anyone that buys the system too.

Finger tight is tight enough with AN o-ring fittings, assuming you are talking about the o-ring non-flared end. The flare end doesn't need to be all that tight either. Snug, you shouildn't ever have to crank down on the fittings to seal. You don't want to tighten an o-ring fitting into submission where the o-ring is completely flattened.

I bought new O-rings for the fitting that attaches to the fuel cell. Summit supplied the most ghetto plastic O rings I've ever encountered. They didn't do anything to seal, so I have some earl's O rings (the rubber kind) to replace them with.

The fittings I had trouble with were the ones that came off the regulator and such, or where the lines attach to the solenoids. I was pretty pissed considering I only had 8psi in the system. I'll try retightening them to snug or just past snug for non o-ring fittings. I think I might have been breaking the seals when I tightened fittings further down stream (undoing what I just did).

And a quick question on setting the fuel pressue (since your an areomotive rep),
I have a very similar setup to the one pictured above, but a strictly low pressure version with a holley black pump. Do I set the fuel pressure (9psi) with the system on and just returning extra fuel through the return line or some other way? I've heard mention of flowing fuel pressure, but wouldn't it be the same with a return line as with the system in use.

Will 9psi through the return line be the same as when the solenoids open or will it drop?

Thanks for the reply.

You should be able to set the fuel pressure accurately with the system just returning fuel via the bypass, assuming you have a well engineered regulator. Not pimping my own product, a Mallory 4309 is a good one too. A holley red, black, blue pump will be fine for a plate type nitrous system. Since you're running a return system the blue and black pump will never go into bypass at 9 psi. (or shouldn't). If you tried to set the pressure above the bypass pressure you would find greatly reduced flow from the system. I'm assuming you have a NX system as they now use a 9 psi setting. Ultimately your flowing fuel pressure is what matters, but your described system sounds just fine. If you have a fuel pressure gauge mounted under hood on the system note that if it is a glycerine filled gauge that the readings may be inaccurate. A glycerine gauge has no atmospheric compensation and the pressure readings will change with the internal gauge temperature due to varying internal gauge pressure with temp.
The "ghetto" plastic sealing washers are designed to be used with a plastic fuel cell. They work fine for their intended use. Jaz uses them and Harwood did as well. Earls stat-o-seal washers are excellent to use with an aluminum cell.
I always use PST paste when dealing with pipe thread. Pipe thread can be difficult to work with because its not always easy to tell when it in far enough. Coupled with varying tap depths between parts and plumbing can be a chore. We only have a handful of parts that utilize pipe thread, most of our systems utilize o-ring AN ports. Make sure when purchasing o-rings that they are designed specifically for the fittings you are using. What I am saying is that they need to be actual AN thickness and diameter o-rings designed for fuel use.

I appreciate the all that info.

It answered a bunch of my questions (even some that I didn't ask). I guess I'll just have to retry tightening the seals on the fuel cell. It's a Jaz, and I just assumed they saved a penny on the seals rather than supply good ones. But if they are right, I'll try giving them a bit more of a turn.

One last question about your comments on the regulator. You mentioned,
A holley red, black, blue pump will be fine for a plate type nitrous system. Since you're running a return system the blue and black pump will never go into bypass at 9 psi. (or shouldn't). If you tried to set the pressure above the bypass pressure you would find greatly reduced flow from the system. and I'm curious if you could elaborate on the pump going into bypass? Do you mean the internal bypass, such as if I were running a "dead headed" system that had no return? I have it setup to run (tank)-(fittings)-(black pump)-(regulator + return line/Guage) and then to the solenoids. As I understood your comments, it won't go into bypass (internally) with a return line to bleed off the pressure? Is the system setup correctly to set the pressue without bypass issues?

I just don't want to find myself on the dyno with a big lean condition. Thanks again!

PS: I have your regulator on my fuel rail and it works great :thumb:

With a true return fuel system the system pressure is at regulated pressure, plus any restriction from the pump to the regulator that would cause a pressure loss.
Say for instance your plumbing pumpimg losses were 1 psi from the pump to the regulator then the pump would see roughly 10psi at the outlet with the regulator. With your higher pressure black pump the internal relief spring should hold the bypass valve on its seat @ 10 psi, thus providing full pump volume at that pressure to the solinoid.
A true return system is one where the supply and demand (outlet) plumbing are on the same plane with no "valve" or cartridge in between. The excess volume is bled off through a valve to maintain pressure.
Some systems incorporate a bypass jet to maintain fuel flow through the system, but they aren't a true bypass design as they still incorporate a dead head regulator and the resultant flow restricting design.
Feel free to tell me what regulator you are using for more info.

It's a holley regulator. I don't remember the part number, but I believe it is the one that comes with the Blue level pumps.

I have a 3 an line with a restriction jet that returns to the tank from the regulator.

The whole system is a Jaz fuel cell, Black pump, holley regulator, 8an line and filter (same size from cell and pump) to a distribution point where it splits to 6an for the DP and 4an for the second stage. It has a 3an return line with a jet (.28 nx I believe) for restriction.

Ok, with that system you will be able to adjust your regulator with the system off, but you won't know what will happen with the nitrous system activated. I am confused as the whether the pump runs the carb too and if it does is it on the same regulator?
With a jet bypass system you will never recover that flow volume, no matter how minute it may seem. If its all on the same system a flow test will be difficult because the flow to the carburetor(Edit: I thought that he was referring to a double pumper carburetor when he said DP, but in fact he has a Direct Port nitrous system) will be an unknown at wot. If its an independant system the you can run a test, but its dangerous.
You would put your plate and plumbing in a bucket and activate the fuel solinoid with the pump on. Note your flowing fuel pressure after it has been activated for a couple of seconds. You will most likely see a pressure drop after activation. Raise the pressure regulator while the system is flowing until it matches your spec. Don't worry about the static gauge reading after the flow test.
We can move to email if it would be better for you. I'll send you my address.

We can move to email if it would be better for you. I'll send you my address.



NO!! Don't do that!

This discussion is too good. You have to stay here. Sorry... Social contract and all. ;)

NO!! Don't do that!

This discussion is too good. You have to stay here. Sorry... Social contract and all. ;)

Haha, I haven't heard from him yet.

I'll post anything relevant when I hear back from him.

Mark

Haha, I haven't heard from him yet.

I'll post anything relevant when I hear back from him.

Mark


I don't mind keeping it here, we kinda hijacked Dave's thread, but it is relavent to the topic too.

I'm acctually runing a stock EFI system and a complete standalone fuel system. The two systems are completely independent of each other.

Does the middle part of your post,
With a jet bypass system you will never recover that flow volume, no matter how minute it may seem. If its all on the same system a flow test will be difficult because the flow to the carburetor will be an unknown at wot. If its an independant system the you can run a test, but its dangerous. still apply to my setup? The jet is only in the return line to keep pressue up, but still allow air to bleed from the system on initial startup.

As to bleeding it, I don't mind and almost assumed I would need to undo the ends and run the system open.
If its an independant system the you can run a test, but its dangerous. You would put your plate and plumbing in a bucket and activate the fuel solinoid with the pump on. Note your flowing fuel pressure after it has been activated for a couple of seconds. You will most likely see a pressure drop after activation. Raise the pressure regulator while the system is flowing until it matches your spec.
If this applys to my setup, should I set the pressue with both ends of the fuel system open? I have two nitrous systems running off this fuel system so do I set it with the most possible fuel flowing? If I set it this way, how is the pressure affected if I only need half the fuel (only using one stage of n20/fuel)?

Also you mentioned the pressue drop, I assumed there would be some sort of pressue drop like every fuel system. How severe did you mean? The two stages of nitrous are roughly a 150 shot a piece and staged 1500rpm apart. I went with a standalone to reduce the lean spikes/fuel rail requirements of a big intank setup, are the problems just less pronounced (smaller lean spike)?

Because my system is so similar to Dave's system pictured above, will prospective buyers have to set their pressure the same way? Is there an alternate method (possibly a different regulator) that allows you to set the pressue with out flowing it into a bucket?

I'm glad others are getting as much information from your posts as I am.

Dave's system is a true return system with our 13301 return regulator. Fuel demands are met first with this system and the excess fuel is returned to the tank to maintain pressure. With a return system, the regulator meters the return volume through a variable orifice. As demand increases, the valve meters down return volume to keep the pressure at the set point. This type of system is very stable and pressure drop during nitrous activation is brief at worst. As long as the pump volume is greater than demand the system will maintain a rock steady setting.
The modified holley 12-803 regulator setup is a dead head regulator that is modified to always flow some fuel through it to allow for static pressure settings and keep the system full of fuel. A dead head regulator requires the fuel to flow through a restrictive cartridge and into the regulator body where the pressure may act on the diaphragm. The diaphragm pushes on a ball in the cartridge that meters fuel into the system. This type of system can have a kind o see saw or up and down pressure graph when you look at a data log.
There is a way to set up you system and check the pressure without taking the whole system off. You already use a jet and return line. What you want to do is take the area of your return jet, and add it to the area of the other two fuel system jets in your system. Find a jet that matches that area. Put that jet in the "return" line and set your pressure. This jet will approximate the fuel flow that wil be on the system when both are activated. After setting your regulator, go back to the old jet and you're all set. You may also just add the area of one fuel jet and test and see how the regulator changes. I would set it for worse case though.
Here's some help:

.028 =.000616 "

I'll use .072" for your fuel jets

.072=.004072 " x 2

.00876" of area needed for the jet to test

.106 jet needed

Area of a jet is: jetId * JetId *.7854


When I first posted this my math was hosed.

Area of jets may be found here:http://www.barrygrant.com/bgfuel/default.aspx?page=84#Nozzles
I know its a competitor, buts its good info.

That is some DAMN GOOD info.

I never would have thought of just swaping a larger jet in to simulate the openings of the others. I will definately use that method and then just set it without taking everything apart.

One last questions, when doing this with a direct port system do I assume the volume of all 8 jets or of just one? Ie...do I use the area of one and then multiply by 8? I would assume multiply by 8.

Thanks for doing some math on a Sat. morning.

Yes, on a fogger type system multiply the area of the fuel jets by 8, or however many nozzles you have.
I'm glad to be able to help.

That is merely an anti blow up the cell like a baloon device. Or anti suck it down like a pop can device. Or anti I can't yank this cap of my cell because its sucked down device. Those cap vents don't flow enough to support the volume of fuel that can potentially be leaving the system under a big nitrous hit.
But I still like it.
You are correct.
The original ones we got did not have diaphram in the cap.The last batch did so to insure proper ventilation we are removing the diaphram.We did a free flow check.We did 16 oz of fuel in 5 seconds.
Dave

Well 90gph is respectable gravity feed. I'm glad you took it into consideration. Thank you for developing a well engineered piece that incorporates our product.

You would put your plate and plumbing in a bucket and activate the fuel solinoid with the pump on. Note your flowing fuel pressure after it has been activated for a couple of seconds. You will most likely see a pressure drop after activation. Raise the pressure regulator while the system is flowing until it matches your spec. Don't worry about the static gauge reading after the flow test.
We can move to email if it would be better for you. I'll send you my address.

I prefer to flow my system using the "before" the fuel solenoid method. Flowing after the solenoid into a bucket does not take into consideration engine vacuum
as seen on a running motor. I think most nitrous manufacturers flow/design
their systems using the "before" solenoid method.

Emil

Well 90gph is respectable gravity feed. I'm glad you took it into consideration. Thank you for developing a well engineered piece that incorporates our product.
You have a great product.
Dave

I prefer to flow my system using the "before" the fuel solenoid method. Flowing after the solenoid into a bucket does not take into consideration engine vacuum
as seen on a running motor. I think most nitrous manufacturers flow/design
their systems using the "before" solenoid method.

Emil


There is no flow in front of the solinoid. The solinoid must open for flow to occur. Every restriction should be accounted for when possible.

There is no flow in front of the solinoid. The solinoid must open for flow to occur. Every restriction should be accounted for when possible.

I disconnect the fuel line from the fuel solenoid and then attach my test line to this line. I have a brass coupler fitting on the opposite end of this line and I insert a flow jet the same area size as I intend to spray with. This end I stick into a fuel jug and turn on the fuel pump and set regulator to desired psi.

The fuel solenoid restriction and vacuum differances are factored in by the nitrous manufactureres when they determine their fuel/nitrous jet size tables.

To be safe, its best to check your plugs after each run and adjust
your pressure/jet sizes accordingly.

Emil

Everybody has their way I suppose. The important thing is that at least an attempt is made to ensure proper fuel delivery for reliable, repeatable power.

TTT for Dave

For my math I did:

Direct Port (DP) 150 shot = .020 Fuel = .000314 * 8 = .002512

For the Single Nozzle I did:

150 shot (at 10 psi) = .052 Fuel = .002124

Return Line I did:

.028 jet = .000616

Added all together for total area = .002512 + .002124 + .000616 = .005252

Total Test Jet size = .082 (.005281 area)