Do I need a adjustable FPR? sr20det 850cc inj

[Luvs2slide]

So I keep hearing different answers as to whether or not to run one. I hear that my stock one will work fine and other say I need an adjustable. I am fixing to do a power upgrade with these items and want to make sure I have all my shit ready to go when it comes time to tune. Heres my parts list:

2871R
850cc sards
PFC D-Jetro
Tomei 256 poncams
GTR Fuel pump
Greddy Intake Mani

I only plan to run about 1.2 bar w/ this for now. Will my stock FPR be ok? I don't want to upgrade if I don't have to. I'm sure with the right tuning, I wont be running too rich which is why I hear peeps run the adj FPR. Any thoughts???

[2fast4y0u]

i have basically the same setup...i would suggest it, unless u tune for it.

[jholman05]

Confused. You have enough injector so bumping up the fuel pressure is not needed. Idk about the GTR pump but 255lph doesnt overpower my stock fpr. What are you tuning it with?

[R33E8]

Yeah.. I'm running 1000cc injectors with a stock fpr on my ka-t.. I do have a fuelabs ready to go in though.. just waiting on some lines...

[DJPimpFlex]

Upgrade your fuel pump and FPR together. Its definitely nice to have a gauge to see that your pressure levels are correct at the injectors, and you need to make sure that with your larger injectors, that you are feeding them the proper amount of fuel at all times.

[Luvs2slide]

i have basically the same setup...i would suggest it, unless u tune for it.

Why would you suggest it?


Confused. You have enough injector so bumping up the fuel pressure is not needed. Idk about the GTR pump but 255lph doesnt overpower my stock fpr. What are you tuning it with?

See, this is what I am thinking as well. GTR < 255lph. THe tune will be with a dataloggit type or identical software where we can view everything. My tuner wants to tune bottom end and top end separately.

Yeah.. I'm running 1000cc injectors with a stock fpr on my ka-t.. I do have a fuelabs ready to go in though.. just waiting on some lines...

With your current setup, are you required to have a adj FPR? Or are you putting in one just to put one in?

Upgrade your fuel pump and FPR together. Its definitely nice to have a gauge to see that your pressure levels are correct at the injectors, and you need to make sure that with your larger injectors, that you are feeding them the proper amount of fuel at all times.

With the GTR pump, it doesn't flow as much as a walbro would, but I I really don't see the reasoning behind all this. The way I see it is this:

If I was running on stock 370cc injectors with my same setup I think the injector's duty cycle would max out. So in order to get that extra "push" out of them I would use a adj FPR to increase that pressure, forcing more fuel. But If I ran the 850cc, I am curious if I would need one altogether since I wouldn't be close to maxing out my duty cycle. Alot of people are just buying shit to get it, and I only want to get it IF I NEED IT.

Anybody else have input on this?

[R33E8]

With your current setup, are you required to have a adj FPR? Or are you putting in one just to put one in?


Nope it's not required.. I'm running a built ka with a gt35r and it runs fine for the most part.. I'm going to be putting in dual walbros and I'm kinda afraid it might overflow the stock fpr..

[alesserfate]

you dont need one

i have sard 850cc injectors
hks 264 camshafts
gt3076r
apexi pfc

running 18psi of boost making 411whp with a walbro 255lph pump and stock fuel lines/rail and its never been a problem (3 years)

get the walbro, ditch the gtr pump

[Luvs2slide]

you dont need one

i have sard 850cc injectors
hks 264 camshafts
gt3076r
apexi pfc

running 18psi of boost making 411whp with a walbro 255lph pump and stock fuel lines/rail and its never been a problem (3 years)

get the walbro, ditch the gtr pump

Why ditch the GTR pump? Granted it is older (used of course). But if the Walbro would go out, it would slowly die out, taking other components with it, all while you dont even realize it. With the GTR pump it will cut off completely not tearing up anything else up. The GTR- pump doesnt flow as much as the Walbros of course. I just don't see why you think the Walbro would be better.

[lazysk8er2]

just upgrade to the nismo type A it should be good enough. and add a gauge to see your readings

[jackal264]

get the walbro, ditch the gtr pump


worst advice i've ever heard, period.

as for the op. adjustable fpr are nice but totally not necesary. one problem that i have seen when running large injectors and high flow pumps is that the pressure can be a bit to high and cause the injectors to actually not completely close when your at idle/low rpm making you run quite ritch at those rpm ranges but it's not something that will affect overall performance just maybe your fuel economy and you won't know if you'll have a problem with it untill you start tuning so again IF you come across that issues you can opt for an adjustable fpr at that time but otherwise its a waste of money.

oh also an adjustable fpr can help if your close to the max duty of your injectors by bumping up the pressure but again not a proble you will run into.

[fliprayzin240sx]

Its not necessary, whether you need it or not, it all depends on your tuners preferance. Some tuner likes a higher than stock pressure so they wont have to tweak the fuel map too much. Some likes to work with the fuel map from scratch so it doesnt matter what the fuel pressure is at. Some has a preferred set pressure to start off at other than stock...

[Luvs2slide]

I see. THanks for the good info. Hopefully this helps others in the future.

[swestermann]

im running walbro, venom 720cc injectors, s15 turbo, 300zx maf, 3in exhaust do i need a fpr?