intake manifold and fuel

[cyrez187]

so i have the obx manifold and fuel rail, i have the stage 2 star kit with hahn's port fueler kit. i was curious if i need to keep my stock fuel regulator,### my portfuler kit came with one. and another thing i have herd nothing good from the obx manifold now should i even bother using the obx manifold and fuel rail,will it give me any gains, ive herd more headache and nothing goes together easily. thank you

 

[clipsit]

I have heard the same, and that it hasn't really shown any gains...for the quality of the product either. I'd say stay w/ the stock manifold and port it, if you have the extra $$$, otherwise don't bother...and just use the stock one...IMO. As far as a fuel regulator...I would assume you would need some kind of AFPR. I am not familiar w/ the portfueler and what's all needed...so anyone else want to take a stab?

 

[VelocitàPaola]

As far as a fuel regulator...I would assume you would need some kind of AFPR. I am not familiar w/ the portfueler and what's all needed...so anyone else want to take a stab?

Correct, you need some sort of rising-rate FPR. If Hahn gave you one, then that's the one you use - disable or take off the stock one. Hahn's FPR should be able to give you appropriate idle fuel levels; which is basically the only reason you would have to keep your stock FPR otherwise (i.e. in the case of a FMU install).

 

[cyrez187]

any advantage to using the obx fuel rail then?oh ya and where in the fuel line does the regulator go?stock one is at the end of the fuel rail. and is a fuel regulator the same as a fmu (fuel management unit)?

 

[VelocitàPaola]

any advantage to using the obx fuel rail then?oh ya and where in the fuel line does the regulator go?stock one is at the end of the fuel rail. and is a fuel regulator the same as a fmu (fuel management unit)?

You'll need to disable the stock FPR, since if you remove it... well, then all your fuel will spill out. Read Corbin's write-up on this:

http://www.2gnt.com/www/corbin/fpr.html

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[VelocitàPaola]

any advantage to using the obx fuel rail then?

I just thought about this... if you decide to use the OBX fuel rail, you won't have to disable the stock FPR. Other than that, I don't know anything specific about the OBX's flow or volume.

and is a fuel regulator the same as a fmu (fuel management unit)?

They're similar, but the two terms aren't quite interchangeable.

As you probably know, fuel pressure regulators are found on all cars to regulate fuel pressure to the fuel rail. The amount of fuel entering the engine is a function of fuel injector duty cycle (how long they stay open) and fuel rail pressure. Since the injectors only have a maximum duty cycle of 100%, the fuel pressure regulators are used to bump up the pressure in the fuel rail, thus giving the engine more fuel as needed. They also have the ability to keep fuel pressure consistent at idle, so the engine is not starved of fuel.

Fuel Management Units (FMUs) are a type of fuel pressure regulator, but they cannot be used in place of the stock FPR. For one, they are only responsive to boost - thus they cannot effectively keep consistent fuel pressures at idle. They also usually have extremely high air pressure-to-fuel pressure ratios (i.e. 1:4, 1:6, 1:8, 1:10, or 1:12). Other FPRs, like the Aeromotive, have much lower ratios (i.e. 1:1). The high ratios stems from the assumption that cars running FMUs have no other means to provide larger amounts of fuel (i.e. an extra four injectors). Aeromotive-type FPRs, thus, are ideally used with 8-injector set ups. Fortunately, they are also able to control idle fuel pressures, and fuel pressure under vacuum.

 

[cyrez187]

ok so where does the fmu go in the fuel system now then?

 

[BigRand]

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=82

That should help.....

The SFMU controls idle as well, but (correct me if I'm wrong) the fmu would go inbetween the tank and the fuel pressure regulator.

Here is some more guides, on the SFMU, but should be similar to the FMU installation

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=58

 

[XMasta19]

hmm....

now don't go getting all fmu's mixed up with just the regular non adjustable rising rate ones. the s-fmu is fully adjustable and can set your idle as well, but look at it's name...s-FMU, and it DOES replace the stock fpr.

sorry, just had to throw that in there...even though you have 2 green bars.

obx intake manifold + fuel rail = garbage...sure some have managed to modify them enough to work....but tell me, what's wrong with your stock ones??

you're a 95, so your fmu will mount in the engine bay (ie. against the firewall)...you will keep your stock fpr. you'll have two fuel lines coming from the rail, one supply one return. I mounted mine where the cruise control would normally go since I don't have that luxery . It will go in-line with your fuel return (connects to hard line on firewall.) so your fmu in will go back to the fuel rail, and the fmu out goes to that hard line against the firewall that goes back to the tank.

blah blah blah....i'm at work, maybe I should get off the internet now

 

[cyrez187]

so i will use the obx fpr and the areomotive fmu.should i leave the stock fpr or remove it?

 

[XMasta19]

so i will use the obx fpr and the areomotive fmu.should i leave the stock fpr or remove it?

woah woah woah...no you will not use the obx fpr and aeromotive fmu at the same time. last time I checked aeromotive didn't make an fmu, just their 1:1 universal fpr. you do not need to use aftermarket fmu and fpr in conjunction with each other. it's one or the other, depending on the fuel setup you're going with. hold on...your vehicle profile says you have built motor and portfueler, why are we even talking about a fmu? u need to get all this situated before u go BOOM my friend.

 

[XMasta19]

...just noticed you've got an uber cool show car. you need to add as much bling under the hood as possible, go ahead and throw it all in there...worry about what needs to be hooked up later

 

[VelocitàPaola]

so i will use the obx fpr and the areomotive fmu.should i leave the stock fpr or remove it?

For your set up you use the FPR included in the Portfueler kit, or an Aeromotive 1:1 FPR, that's it. No FMUs, no stock FPR... look at the diagram I posted before, that's where It's supposed to be installed. If you keep the stock fuel rail, you'll need to keep the stock FPR, since it holds all the fuel in, so make sure you disable it by following the link I left in one of my previous posts.

 

[VelocitàPaola]

now don't go getting all fmu's mixed up with just the regular non adjustable rising rate ones. the s-fmu is fully adjustable and can set your idle as well, but look at it's name...s-FMU, and it DOES replace the stock fpr.

True. True.

 

[cyrez187]

ok i have this fmu
http://www.jegs.com/webapp/wcs/stor...atalogId=10002&storeId=10001&categoryId=19931
and this obx fpr
http://cgi.ebay.com/OBX-GUAGE-FUEL-...ryZ43808QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

so i just need to know what i should hook up ### currently i have the 8 injector setup with 255 fuel pump.
and when done so i guess remove the stock fpr forsure right

 

[BigRand]

No offense man, but if your using the porterfuler 8-injector set up, why don't you use the instrucitons that comes with that, not to mention hahn has some excellent customer support, you get what you pay for.

Maybe this will help a little,

http://www.2gnt.com/www/corbin/8inj.html

 

[VelocitàPaola]

No offense man, but if your using the porterfuler 8-injector set up, why don't you use the instrucitons that comes with that, not to mention hahn has some excellent customer support, you get what you pay for.

Maybe this will help a little,

http://www.2gnt.com/www/corbin/8inj.html

I agree. I think your just confusing yourself. Didn't you say Hahn included an FPR with the Portfueler? Use that if it did...

Otherwise, use either of the FPRs you linked to (the top one isn't an FMU, it's just an adjustable FPR).

 

[baxsom]

i just installed my portfueler

fuel tank to stock fuel rail to portfueler rail to aeromotive 1:1 to return line

you cannot use a rising rate fmu

the portfueler adds fuel by way of the injectors not bumping up the fuel pressure

the stock fpr is disabled

honestly do a lot of research before you start this install if you are asking questions like that.

the PF is great but if you dont know what you are doing and how all of the parts work together BOOM!!!!!!!!!!


i seriously also hope that you have a built forged internal engine and at least a stage 3 clutch

 

[cyrez187]

does anyone have pics of their process of installing the port fueler?

 

[VelocitàPaola]

does anyone have pics of their process of installing the port fueler?

Look at the link Rand gave you. It's how Corbin installed his (and he made his from scratch!). The only differences are, instead of drilling holes and mounting the extra injectors, you simply bolt up that plate with the Portfueler kit.

You have it pretty easy since Hahn even programs the thing for you.

 

[VelocitàPaola]

Here, I made you a little diagram. The only difference is that the "stock" fuel rail on this is in a side-to-side configuration whereas yours (the early fuel system rail) is a same-side rail.

All you do is route the return coming from the stock rail to the inlet on the Portfueler rail.

The 1:1 AFPR comes after the Portfueler rail, and then everything goes back to the tank.

Call Hahn if you still have trouble, they'll walk you through every step.

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[VelocitàPaola]

Here's an updated schematic specifically for you too.

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[cyrez187]

thanks very helpful, now one more thing if i decide to use the obx fuel rail. there is no lip or connection for the vacumm source from the stock fuel rail.do i need a vacumm that goes from the intake manifold to the rail?

 

[VelocitàPaola]

thanks very helpful, now one more thing if i decide to use the obx fuel rail. there is no lip or connection for the vacumm source from the stock fuel rail.do i need a vacumm that goes from the intake manifold to the rail?

WTF

You misread the schematic. Those aren't vac lines, they're fuel lines. The only vac line there is, is the one that goes to the FPR.

 

[XMasta19]

why use the obx fuel rail...I don't see any need to. Just follow the schematic, done sir done. it's cake yo, and like it has been said already....you paid all that dang money for the portfueler, I'd be using that hahn tech support left and right.