Nismo FPR-Does it fit?!? Alternatives?!?

[MarkEmark]

Well the boobs over at FA were incapable of answering my questions adequately, so i'll try my luck here

I want to buy an adjustable fuel pressure regulator, but I need to get one that is going to DECREASE the pressure below the 43 psi @ 0 vacuum to lean the car out a bit, not increase it like everyone else does.

Therefore, I can't use another FPR in conjunction with the OEM one at the end of the rail since it would never let me go under 43 psi (at no vacuum), only higher.

It'd be a lot easier if I could just put another FPR in-line, but I can't do that because I want to lower pressure.

First question:When they rate adjustable FPRs, do they rate them @ idle, which is around 35 psi, (~20 in. Hg vacuum) or at no vacuum (43 psi)?

Second question:The Nismo adjustable FPR is supposed to bolt right in the fuel rail, but I've heard of fitment issues, and it seems like a PIA to install it an then not even be able to adjust it. Does anyone have one installed on a KA24DE fuel rail/know someone who does? Does anyone know how they fit? From the looks of pictures the adjustment screw faces the valve cover at the very far end toward the firewall--but then I think, why would NISMO, a performance company, design an adjustable FPR that when installed where it should be is almost impossible to adjust? Does anyone actually have one of these/a pic of one installed?

Third question: What is its range of adjustability of the Nismo FPR, ie, how low can it go?

Fourth question: I may just get a more adjustable, nicer FPR and make a custom bracket to mount it in the fuel rail so that I can mount it somewhere that I can adjust it/get to it conveniently. Does anyone know who makes a good, economical, bulletproof FPR that has barb fittings for regular fuel injection hose? Most importantly, such a FPR needs to be able to adjust to BELOW 43 psi @ 0 vacuum, perhaps as low as 33 psi. (I can't get one with aeroquip or AN fittings, although if such a FPR had female threads, I could screw in a pipe fitting that has a barb at the end for hose, assuming they were fairly standard size).

Any input guys?

[spitz7985]

i know a guy with one on his s14, i'll talk to him

[MarkEmark]

awesome, i'd appreciate that. See if you can take a quick peek where it sits/points in the rail and if it looks accesible or not...

[MarkEmark]

Spitz, you ever talk to that guy with the nismo fpr on his s14?!?

Thanks

[spitz7985]

i sent him this thread's link.

[Aaron_9349]

ok, I have the FPR in my KA and it is not that hard to put in. I first tried to do it just by unscrewing the old one... DON"T DO THIS. The easiest way to attach it is to simply take of the entire fuel rail. This way you won't strip the two tiny screws. The bad part is... I have not found a good way to get a wrench in to adjust it. To adjust it, you have to take the whole fuel rail off, and then adjust the screw on top. Then, if you have it all the way up, you have to bolt the fuel rail back on. It is impossible to adjust while on the car, since it does hit the head. I adjusted mine by setting it, running the car and letting it idle, then taking the fuel rail off, adjust it, and see how it effected it. Yet, on my Greddy fuel rail (that came with my greddy turbo kit) it does fit above the head a little more, since the fuel rail is now above the injectors. I haven't installed the kit yet, in process of building the engine first. When I install the fuel rail, i'll let you know how it fits. If you want I can send you a pic of the stock rail with the Nismo AFR. As for the amount of pressure that it can adjust to... I don't know. I am having this looked at by my machinist, and seeing if he can test it in his shop without doing it on the ka... Since the ka is apart. I'm also going to ask him to test out the JWT adjustable cam gears that i'm buying for the build up. I hope this helps

[MarkEmark]

Thanks a lot, that helps a lot.

That sucks that Nismo made a unit thats impossible to adjust while on the car.

However, I can set up a closed-loop system with the extra fuel rail/injectors I have lying around and a pressure gauge/pressure source to adjust it to the exact pressure I want it to be at, and then install it. It can go below the 37 psi @ idle though, correct?

What sucks is that I don't know how much lowering the fuel pressure will correspond to for an air fuel ratio....

Thanks againMarc

PSA picture would be greatly appreciated! E-mail me at:[email protected]Thanks

[IvoryJ30t]

why dont you just remove the fuel rail, and have a fitting welded to the end of the rail, that way you can use an external FPR like an aeromotive unit or something?

[MarkEmark]

From my first post:

Fourth question: I may just get a more adjustable, nicer FPR and make a custom bracket to mount it in the fuel rail so that I can mount it somewhere that I can adjust it/get to it conveniently.



Having a fitting welded to the rail is a very good possibility; I just wanted to confirm that the Nismo unit was unadjustable when installed on the car.

Still wish Nismo made something that was adjustable while it was on the car. Hmmph.

[j-z]

i second getting an aeromotive type regulator. it wouldnt really be that hard at all. instead of welding a fitting on the end something cleaner would be too take our stock fpr and trace the bottom of it where it mounts to the rail. trace it out on some 1/4'' aluminum, cut it to shape then port a hole out in the flange you just made to match the outlet on the fuel rail. then get an aluminum nipple the same ID size as the hole you ported on the flange. then take it to a machine shop or any shop that can tig aluminum. weld the nipple on the flange (which shouldnt cost more than 10 bux). doing it this way would be cleaner and you can always convert back to stock. hook your hose up to the nipple to go to the fpr and then the other hose on the fpr to the hard return line. **** i may even do this.

[MarkEmark]

Good idea--how much do aeromotive units go for, and how is their quality? What is their range of adjustability?

I need one with just regular nipple inlets/outlets that will work with standard rubber fuel injection hose. The inlets/outlets can be female so long as I can find male nipples that will fit the female socket and have the correct size OD on the nipple.

[j-z]

i think theyre usually about 150. and your last paragraph is exactly what i had pictured in my mind. it would be really clean and you can mount it to the firewall. i think all of the regualtors come with female tapped inlet/outlets. then what you just said get some barbed or nipple male fitting to screw into the regulator. ima llok in my jegs real quick and see how much they are.

[j-z]

ok mark i found it. im gonna type the description. developed for high horsepower applications with a base pressure that is adjustable from 30-70 psi. provides two inlet ports, one return port and 1/8'' npt gauge port. part 027-13109 uses 06AN inlets and return (which is what you want, the other list for 10AN inlet and 06AN outlet) features a boost reference to increase fuel pressure on a 1:1 ratio from forced air induction powerplants. alchol compatible <---- yeah baby! the part you want is $129.99 suweet! i bet thats cheaper than the fancey 'nismo' regulator. whats cool about it is the port so you can thread a gauge right into it. heres their number 1-800-345-4545

[IvoryJ30t]

exactly, you can hook up a gauge to the regulator, and always see what you base fuel pressure is. plus it makes adjusting much easier.

[MarkEmark]

Thanks j-z, this is some good info.

The fuel pressure gauge is a novel idea to have right under hood and would make adjustment a breeze.

This looks nice, except for the fact that it's an OBX.

http://cgi.ebay.com/ebaymotors...68815

When they say 30-60 psi adjustable for fuel pressure regulators, does this mean at idle (~ 20 in. Hg) or at 0 vacuum, 0 pressure?

In any case, this FPR is just one among many of my upcoming projects (battery relocation, upgrade turbo, all new intercooler piping/intercooler), so it may be a while before I actually get one on the KA.

[Aaron_9349]

Here is a pic of it on my stock fuel rail. I'll email you a few others soon. THanks,

[j-z]

i dont see why that obx one wouldnt be able to get the job done. it even already comes with a gauge too. when theyre refering to the pressure i would imagine that its at idle. but not 100% positive though. and mark do you have any pics of your car? sounds like it would be interesting to see. thanks

[Aaron_9349]

Yeah, looked at the pic of the OBX one, but it looks like its gonna put the adjuster screw in the exact same place as the Nismo (right against the Head). Unless you're planning to mount it verticle or somewhere else along the fuel line. The pressure is its range of flow, from 20lbs to 60lbs. and usually you want the pressure to go up 1lb for every 1psi from the turbo (this is where your walbro pump comes in handy). SO... is your walbro pump pushing too much fuel in, and thats why you need to adjust the Pressure at the regulator? Or, is it possible your stock regulator is worn out/through and is doing little regulating. I suggest hooking a fuel pressure gauge into your fuel line going to the regulator. This may help you compare the presure before and after you change out the regulator. There seem to be a lot of different possiblities for why your cars running rich. I hope this helps.

[MarkEmark]

I had quite a few pics of my car hosted by the eniety pichost, but unfortunately that site has been down for weeks. IF you really wanna see some, I can email ya. One day when I have a lot of time on my hands I'll set up a website.

Aaron-The reason I know my car is running rich is because JWT ecu's are notorious for running KA-Ts rich--and I have the standard JWT / 370 cc setup--I just wanted to install the adjustable FPR to tinker with the fuel pressure a bit and to lean it out for some more power.

With regards to attaching the fuel pressure regulator, if I don't go the NISMO unit, I will have to find some way to put the FPR in, mounted in a place that's EASY to access but mounted so that it eliminates the OEM fpr (otherwise, the fuel pressure couldn't be decreased past what the stock fpr puts out at idle, around 37 psi).

I know my OEM fpr works fine; when I had it off I tested it with my spare fuel rail/injectors, and it works in a 1:1 ratio and any aftermarket one I purchase will also have to be in this 1:1 ratio. My hi-flow, HI PRESSURE fuel pump could be pressurizing the fuel a bit to much as well, but I thought the FPR regulated this pressure despite what pressure the pump was putting out.

WHen I do upgrade to an aftermarket FPR, I'll definitely have a gauge in there to see what it's doing...THe NISMO unit is still an alternative as I could program it to the exact pressure that I want it to be at when it's uninstalled (with my old fuel rail/injectors/fuel pump/pressure gauge/pressure source), but the problem with using the NISMO one is that I don't know how MUCH I want to lower the pressure--and I'd definitely rather be a little rich than a little lean.

I could even use the NISMO unit but just try to mount it somewhere else, and then when I finally get the beast dynoed, I'd be able to adjust it while I was there and see how much decreasing fuel pressure correlates to a leaner a/f ratio.

I'm thinking of just having a fitting made that connects to the end of the fuel rail that has a nipple to attach hose to--then I'd run this hose AWAY from the engine, right near the left side of the engine bay, (but not too far away as to have to have really twisty, snaked fuel lines going to/from the regulator) and then attach it to an aftermarket Fuel pressure regulator with gauge, possibly the Nismo unit. Not sure how I'm going to get this fitting made, however..perhaps I could even chop the end of the OEM fpr that attaches to the fuel rail and have it welded to a properly sized nipple--but I'd have to have a way to secure it to the fuel rail using the two screw holes, obviously.

[Aaron_9349]

Well, if you have two fuel rail setups and two stock regulators, might as well give it a try. Worst case, you lose one of your sets, and install the other one. And, if you really need another fuel line/stock regulator/or stock injectors after that...I'm pulling mine for my turbo kit (since it comes with a fuel rail, 370cc's, and i have the nismo regulator) and putting it up on ebay end of march/early april. Give it a try. LATER

[j-z]

if you set it up exactly how i described it would work perfectly fine. all you gotta do is make that flange get an aluminum nipple and weld it to the flange. use the existing fpr screws and make a gasket to bolt it to the rail. now you can hook a hose up to the nipple and voila you have a wide variety of aftermarket fpr to choose from. aaron-that obx regulator isnt made to bolt to the rail. its made to be used like the aeromotive type units inline with the return hose. its really simple to get it to work. i see the obx one has a breckt on the back in which you could use to mount it to the firewall. or mark if you REALLY wanted to use the nismo regulator you can just make two of those flanges that i described ^^^^ up there to you on how to make. then get like a smooth aluminum 90 degree bend and weld the flanges on the end of it to place the nismo regulator in a better spot so you dont have to take the rail off everytime you adjust it. but id rather go with the aeromotive unit because you can screw a gauge into the unit itself. but either way both of my ideas would work.

[nismofan14]

Instead of welding a fitting on your fuel rail, check out these fittings JUN fpr fittings . You might be able to find better prices on them.

[MarkEmark]

Awesome!

Those would be perfect....and I'm assuming they fit the KA24DE fuel rail, correct? Because the site looks like it's 240 oriented, although it may be made for the sr20det fuel rail...anyone know if the ka fpr will fit an sr fuel rail and vice versa?

$61 is damn expensive, but hey, it's convenient as hell. Thanks again nismofan!

[j-z]

it would no doubt be cheaper to make your own if you have the correct sources.

[MarkEmark]

it would no doubt be cheaper to make your own if you have the correct sources.

It usually is, but it's a whole lot easier to just buy one already made. I'd have to source the part that goes into the fuel rail makin sure it had a spot for the o-ring (unless I cut it off from the old FPR), i'd have to find a correct sized niple, I'd have to have the two pieces welded together, sandwiching an aluminum plate that I'd have to fabricate myself....

I'd feel more comfortable with one mad by JUN--$60 ain't that bad.

Does anyone know if it'll fit the KA24DE fueil rail if the JUN FPR fittings are made for an sr20det?!?

[nismofan14]

yes they will fit both fuel rails. I don't know for sure but maybe one of our sponsors can get you a better price. Silviawerks sells JUN parts.

[Nathan]

Why not just use braided stainless lines and AN fittings? As much as I hate AN fittings its probably the cleanest, simplest way to do it.

[MarkEmark]

I say no to AN hose/fitting because then I'd feel like a chump if I didn't do my whole fuel line in AN fittings....the stock fuel rail has all hose and barb fittings, and without changing the metal parts of the fuel line, I don't know how you'd attach AN fittings.

I'd like to have EVERYTHING in aeroquip ss hose, but that's a lot of money and would be unnecessary. I'm just going to get a nice (probably aeromotive) unit and mount it somewhere conveniently, and have the gauge right there...Actually, I think I may end up making that fitting for the fuel rail, as I have access to a lathe and can solder stuff together...my dad loves doing stuff like that, so I think I'll save myself the $61....

I'll keep ya posted.

marc

[Nathan]

Ahhh, good point, i forgot I went to a very un-stock fuel setup and most everything changed

[WDRacing]

I never bothered readin every single post, so if i'm repeatin info just deal with it...lol. If I understand the question, you want to lower the base fuel pressure at idle. Which can be done by removing the stock FPR and using one of choice.

If you want a cheap FPR that works well, heres a link. I used it on my Skyline, actually alot of my frinds did as well. http://www.overboost.com/obs/product.asp?pid=2628

Hope that helps...