FPR options for us KA-T that are still using the stock fuel rail

[Jookmasta]

well ive been looking and looking as to what are my options with using an FPR and my factory stock rail. I know of the NISMO unit but i have found two threads stating that you have to remove the fuel rail to actually adjust it. now granted thats not really a big deal, i really think that doing all of that really takes away from the point of actually using it. I talked very briefly to structure about it and he says that i could grind down the valve cover a little to make it work but i feel that even that makes me not want to spend the hundred bux on it. So, is there any other options? I did see markemark fabricate some piece so that he could run an aeromotive but unless he has another one of those pieces to sell, is there any other units out there?

[1WheelWonder]

Great question, I am interested as well.

[Structure240sx]

i meant to ask why do you want an adjustable fpr? get more out of your current injectors?

if so adding 10psi base fuel pressure only increases injector flow about 25cc. save up for some bigger better injectors if this is the case

[Jeff240sx]

I haven't switched back over to my sidefeed setup.. so I don't know for certain on this. But.. it seems that even if you can't get a socket on it, surely an open-ended wrench would get it. I don't think Nismo would build something adjustable and place it so it's not. But again, I would like to see pics of the issue.-Jeff

[Jookmasta]

well i am looking into getting an FPR partially due to getting some more out of the injectors but the main reason is to adjust the fuel pressure due to the upgraded fuel pump. i dont have hard figures yet since my fuel pressure gauge isnt installed yet but i figured that my base fuel pressure may be too high. I know that increasing/decreasing the fuel pressure can mess with the A/f's throughout the entire powerband so that would also help when tuning. But u are right, if i do want more fuel, larger injectors are the way to go, but this still wouldnt solve the fuel pressure issue (if one exists..)

the two threads of interest for ya jeff:

zerothread?id=85021 zerothread?id=55435

[AZhitman]

Hmmmm.

I was JUST discussing thias same issue with Marc from IAP a few minutes ago, may want to call him and hear what he has to say about it.

[Aaron_9349]

I have the Nismo one, built for the 240, not the universal one, and in order to adjust it when i had the stock side feed fuel rail, I had to pull the whole full rail up. I couldn't get a wrench between it and the firewall. But, I now have top feed, which gave me some room to play with lines. The problem is the curve of the inlet point, it is curved so that it meets the fuel line, but this prevents you from twisting the unint to access the adjustment nut on top, and places it against the head.

I have looked into this problem b4 I bought the top feed setup, and I came up with a few things I was considering to do.

I first considered the universal nismo FPR, but that seems it would cause the same problem.

Then I found a fitting adapter at Phase2motortrend.com

It connects to the same place as the stock FPR, but simply has an inlet fitting, at a 90degree angle. So, you could buy the universal nismo FPR (type b), which has an inlet and outlet hose connection. You would just splice it into the fuel hosing b4 the rail.

This is what i figured to work the best to solve the crappy location issue. The addapter is $50, listed at phase2.

Hope this helps

[rn240sx]

Im running stock fuel rail with stock fpr.. My last motor ran the same setup at 16 psi..I dont see why you would wana go more than 1:1 ratio...

[Structure240sx]

the nismo is also a 1:1 ratio, it is able to adjust BASE fuel pressure

[fabio420]

I'm not sure if this is the answer you're looking for, but I used an 8:1 rrfpr. It cost me 50 dollars. With it, my walbro 255 and my safcII I was able to push the stock 260 cc injectors to 220rwhp and 252 lbs of torque with 12 lbs of boost at the dyno machine. It leaned out at 14.1 psi. This was temporary, as I'm installing the 370 cc injectors. I'm actually trying to do some research on whether I want to keep the rrfpr with the new injectors, or if there is no point. If I get rid of it, you can definetly buy it if you want it.

[Jeff240sx]

I'm not sure if this is the answer you're looking for, but I used an 8:1 rrfpr. It leaned out at 14.1 psi.

You do realize that's 155psi fuel pressure, right? And, according to walbro's flow vs. pressure graph, it pumps 0 gallons at 155psi...-Jeff

[nissanfanatic]

You do realize that's 155psi fuel pressure, right? And, according to walbro's flow vs. pressure graph, it pumps 0 gallons at 155psi...-Jeff

My thoughts exactly....

[fabio420]

I underswtand. Iknow that when I leaned out it was due to the fuel pump, but until 12 -13 psi the car runs great.

[Jeff240sx]

I underswtand. Iknow that when I leaned out it was due to the fuel pump, but until 12 -13 psi the car runs great.

Ok.. at 120psi, the Walbro 255L/hr high pressure pump flows 1 gallon per hour. Now, 1gph is enough fuel to feed about 12 horsepower at wide open throttle.Also, 120psi is 9.5psi boost x 8:1 rrfpr. So, you don't just run lean at 9psi, you run dead lean, to the point where the pump cannot pump anymore fuel.

So.. I'm not saying you're lieing.. but you're probably not telling the truth. Mathematics says 14psi on a 8:1 fmu with a Walbro is unpossible.-Jeff

[Jookmasta]

in regards to fabio, i am NOT using an FPR to get more out of my injectors. I can technically get more A/F adjustments due to me playing around with the base fuel pressure. The point of me getting the FPR is to play around with the base fuel pressure. Thanks for the info Aaron as the fitting seems like it would be more ideal than anything else. at phase2, they also had another fitting made by hks which allows u to use the aeromotive fpr's by having a -6AN outlet on that fitting. i am now looking into which will be the cheapest route as now the price of the fpr plus the fitting is getting kinda close to other stuff.

And to fabio, i know of no one running sr injectors with an FMU. I would highly suggest against that as most people with the SR injectors are using a piggyback to control em.........

[fabio420]

So.. I'm not saying you're lieing.. but you're probably not telling the truth. Mathematics says 14psi on a 8:1 fmu with a Walbro is unpossible.-Jeff

So you think that there's no way that I put 220rwhp and 252 lbs of torque on stock injectors and MAF?Check back here TOMORROW and I'll take pictures of the dyno sheets and post it.I'm not planning on using the rrfpr with the 370 cc injectors, but I knwo what I pushed the stock injectors to. If I ran 14.6 with 3/4 tank of gas and .5 reaction time (with stock injectors), I think the dyno sheets are accurate. And the car has been driving fine for 2 weeks, including 2 one and1/2 hour drives.(full boost is 11-12)If you like to see it for yourself, I'd be happy to show you. I'm in south florida.

[MarkEmark]

well ive been looking and looking as to what are my options with using an FPR and my factory stock rail. I know of the NISMO unit but i have found two threads stating that you have to remove the fuel rail to actually adjust it. now granted thats not really a big deal, i really think that doing all of that really takes away from the point of actually using it. I talked very briefly to structure about it and he says that i could grind down the valve cover a little to make it work but i feel that even that makes me not want to spend the hundred bux on it. So, is there any other options? I did see markemark fabricate some piece so that he could run an aeromotive but unless he has another one of those pieces to sell, is there any other units out there?

It's really funny that you mention this, because I actually WILL be selling this elbow very soon once I upgrade my fuel (by next weekend). It works perfectly and allows to run a FPR thats away from the engine in an easy to adjust place.





It bolts right into the fuel rail like the stock FPR, sealed by an o-ring. It was a pain in the *** to have made though.



And theres the Aeromotive adjustable fuel pressure regulator/liquid filled gauge.

Drop me an email if you want it before I put it up for sale...

[email protected]

[onosqv]

Is that an sr20 engine torque dampener? I'm curious because I've always seen them only advertised as sr20 torque dampeners and never ka ones.

And ooo, Jookmasta has someone to bid against for that fpr flange (if you are selling on ebay and not on the forums - and if on the forums, I may get to it first, hehehe).

[MarkEmark]

Is that an sr20 engine torque dampener? I'm curious because I've always seen them only advertised as sr20 torque dampeners and never ka ones.

And ooo, Jookmasta has someone to bid against for that fpr flange (if you are selling on ebay and not on the forums - and if on the forums, I may get to it first, hehehe).

No, it's not. I made it myself with a hatch-strut from Autozone for $16. It actually works quite well at taking some of the slop out of the engine rocking...but now that I have NISMO motor and transmission mounts it's probably superfluous. That, and where its bolted (into the intake manfiold) isn't exactly the strongest point, but the worst that happens is that hole strips, and nothing goes there now anyhow so I don't care...

If you want the flange drop me an email...and make me a reasonable offer. I'm not gonna rip you off for $50 like phase2motortrend, but this was not an easy piece to fabricate, that's for damn sure.

[email protected]

[Jookmasta]

u have mail and that is one of the biggest rip off's for that hks adapter.

[DammitBobby]

Hmm, why don`t you just disconnect the vacuum line from the stock FPR and add a AFPR? Basically you would be disabling the stock FPR and would not have to make or buy a fitting.

[DRIFTEADOR]

^ cause the stock fpr would hold pressure to ~43.5psi in vacumm when the motor wants less

[MarkEmark]

Hmm, why don`t you just disconnect the vacuum line from the stock FPR and add a AFPR? Basically you would be disabling the stock FPR and would not have to make or buy a fitting.

For me the whole reason of getting a new FPR was so I could run LOWER than stock fuel pressure at idle (OEM is ~34.5 psi). Getting an adjustable one in-line with the other one would only allow me to increase the fuel pressure.

[nissanfanatic]

So you think that there's no way that I put 220rwhp and 252 lbs of torque on stock injectors and MAF?Check back here TOMORROW and I'll take pictures of the dyno sheets and post it.I'm not planning on using the rrfpr with the 370 cc injectors, but I knwo what I pushed the stock injectors to. If I ran 14.6 with 3/4 tank of gas and .5 reaction time (with stock injectors), I think the dyno sheets are accurate. And the car has been driving fine for 2 weeks, including 2 one and1/2 hour drives.(full boost is 11-12)If you like to see it for yourself, I'd be happy to show you. I'm in south florida.

I wanna see an AF chart.

[toki]

drill + tape + flare fitting = any FPR your little heart desires.

[fabio420]

Since you were not the first to ask for the proof, I finally was able to post it. These are the dyno results with an automatic with stock injectors and a stock MAF and an 8:1 rrfprhttp://nissaninfiniticlub.net/...t=500http://nissaninfiniticlub.net/...t=500

[nissanfanatic]

Schweet...

I was like WTF on the 220whp run.haha Then I noticed it was by MPH.lol

Way to show us up!!! Congrats on the numbers.

[Jeff240sx]

Schweet...Way to show us up!!! Congrats on the numbers.

First, I don't believe that is a KA graph. Either of them. I've not seen a curve that flat for that long on anyone's KA... Next.. something obviously isn't working correctly, because the Walbro CAN'T flow that much pressure... Could you have a 4:1 or 6:1 disk in the FMU?-Jeff

[fabio420]

and that was on 12 psi of boost!

[DammitBobby]

I was making a point of why would you buy an adapter to replace the FPR when all you have to do is disconnect it. Then you can install an external FPR.