new fuel system upgrade questions? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

drift_king · 01-01-2010, 09:11 PM

i have a greddy rail and rc750's. -6AN fitting on the rail. what would be the simplest soultion to running the fuel lines? install the right fitting onto the hard lines and add ss lines and boom im done? the 750's are peek and holds,

also what fuel pressure reg. should i pick up?

robertftw · 01-01-2010, 09:39 PM

Run new lines from back of the car forward. With that size injector it sounds like you are going for 400+hp or run e85 or something like it so you will need the volume of larger lines. How much power you plan to make? less than 500hp -6 feed line should be good enough above that -8 should be used.
Aeromotive makes nice fuel pressure regulators, they are the only ones I've used so that is all I can suggest.

Master Chief · 01-02-2010, 04:58 AM

Thats just missinformation.
I have dynoed over 530HP, with 850cc injectors, pump fuel, and stock fuel lines and rail, wich I.D. is much smaller than AN6 I.D.

I would run 6AN but not bigger, especcialy for any power you can ever make on those injectors - and thats only if you insist on going to AN fittings.
Otherwise in your case, i would remain stock.
Runing bigger lines, just means your pump needs to work much harder to maintain fuel pressure.

robertftw · 01-02-2010, 07:21 AM

It is not misinformation it is what is ideal for setting up a proper fuel system. And I have no idea how you made 530hp to the wheels with 850cc injectors on a 4 cylinder The duty cycle must be well into the 100's,or you were spraying. What fuel pump were you using? and If you are running the 850's at full capacity your trying to pull almost 2.5 times more fuel than the stock system is designed for I wouldn't trust my motor with those lines. If the o.p. is staying below 400hp then IMO stock lines are fine above that IMO lines should be upgraded.

drift_king · 01-08-2010, 02:12 AM

you guys are great, im staying with stock rail, work smarter not harder!
my goal is max 350 ponys. selling off this stuff and buying some 550cc

THANK YOU FELLAS!!

bejota180sx · 01-08-2010, 12:05 PM

keep the 750s if your thinking about 350, better than maxing out 550s or running them close to a high load

bl3ujay07 · 01-08-2010, 12:39 PM

^^^Agreed. 550's are not enough. I had the sard 550cc that were rated at 320 but were maxed out with my gt2871r at only 1.1 bar. i would stick with the 750's if i were you.

robertftw · 01-09-2010, 10:22 PM

^^agree with these guys. If you go for more later you will have some fueling left in those injectors. 750's should support around 380hp @ a 80% duty cycle.

zurud · 01-21-2010, 03:15 AM

Peak and hold injectors are normally low impedance injectors. You need to add resistors. Probably injector driver too. Or you will fry your ecu.

Master Chief · 01-23-2010, 05:29 PM

I am peaking at 80% duty at 7300 RPM. Using pump fuel, AFR's around 11.8 .
The power is at the HUBS - 530HP, so meaby you are a bit confused with ATW power.
Still - I have the graphs to prove it - they have been posted here, several times.
Do a search on my user name.

Saying that 6AN lines "should" be good enough for 500hp, IS missinformation, or just plain wrong - take your peak.
Stock line is much smaller I.D. then a -6 line, and it works fine.

Anyway.....whatever.

01-01-2010, 09:11 PM	#1
drift_king Zilvia Junkie Join Date: Aug 2009 Location: tampa Posts: 416 Trader Rating: (6) Feedback Score: 6 reviews	new fuel system upgrade questions? i have a greddy rail and rc750's. -6AN fitting on the rail. what would be the simplest soultion to running the fuel lines? install the right fitting onto the hard lines and add ss lines and boom im done? the 750's are peek and holds, also what fuel pressure reg. should i pick up?

01-01-2010, 09:39 PM	#2
robertftw Zilvia Member Join Date: Sep 2006 Location: florida Posts: 148 Trader Rating: (8) Feedback Score: 8 reviews	Run new lines from back of the car forward. With that size injector it sounds like you are going for 400+hp or run e85 or something like it so you will need the volume of larger lines. How much power you plan to make? less than 500hp -6 feed line should be good enough above that -8 should be used. Aeromotive makes nice fuel pressure regulators, they are the only ones I've used so that is all I can suggest.

01-02-2010, 04:58 AM	#3
Master Chief Zilvia Junkie Join Date: Feb 2006 Location: Israel Posts: 332 Trader Rating: (3) Feedback Score: 3 reviews	Thats just missinformation. I have dynoed over 530HP, with 850cc injectors, pump fuel, and stock fuel lines and rail, wich I.D. is much smaller than AN6 I.D. I would run 6AN but not bigger, especcialy for any power you can ever make on those injectors - and thats only if you insist on going to AN fittings. Otherwise in your case, i would remain stock. Runing bigger lines, just means your pump needs to work much harder to maintain fuel pressure.

01-02-2010, 07:21 AM	#4
robertftw Zilvia Member Join Date: Sep 2006 Location: florida Posts: 148 Trader Rating: (8) Feedback Score: 8 reviews	It is not misinformation it is what is ideal for setting up a proper fuel system. And I have no idea how you made 530hp to the wheels with 850cc injectors on a 4 cylinder The duty cycle must be well into the 100's,or you were spraying. What fuel pump were you using? and If you are running the 850's at full capacity your trying to pull almost 2.5 times more fuel than the stock system is designed for I wouldn't trust my motor with those lines. If the o.p. is staying below 400hp then IMO stock lines are fine above that IMO lines should be upgraded.

01-08-2010, 02:12 AM	#5
drift_king Zilvia Junkie Join Date: Aug 2009 Location: tampa Posts: 416 Trader Rating: (6) Feedback Score: 6 reviews	you guys are great, im staying with stock rail, work smarter not harder! my goal is max 350 ponys. selling off this stuff and buying some 550cc THANK YOU FELLAS!!

01-08-2010, 12:39 PM	#7
bl3ujay07 Zilvia Addict Join Date: Feb 2008 Location: norcal(209) and socal(805) Posts: 691 Trader Rating: (6) Feedback Score: 6 reviews	^^^Agreed. 550's are not enough. I had the sard 550cc that were rated at 320 but were maxed out with my gt2871r at only 1.1 bar. i would stick with the 750's if i were you.

01-09-2010, 10:22 PM	#8
robertftw Zilvia Member Join Date: Sep 2006 Location: florida Posts: 148 Trader Rating: (8) Feedback Score: 8 reviews	^^agree with these guys. If you go for more later you will have some fueling left in those injectors. 750's should support around 380hp @ a 80% duty cycle.

01-21-2010, 03:15 AM	#9
zurud Zilvia Junkie Join Date: Aug 2009 Location: evansville, in Posts: 391 Trader Rating: (4) Feedback Score: 4 reviews	Peak and hold injectors are normally low impedance injectors. You need to add resistors. Probably injector driver too. Or you will fry your ecu.

01-23-2010, 05:29 PM	#10
Master Chief Zilvia Junkie Join Date: Feb 2006 Location: Israel Posts: 332 Trader Rating: (3) Feedback Score: 3 reviews	I am peaking at 80% duty at 7300 RPM. Using pump fuel, AFR's around 11.8 . The power is at the HUBS - 530HP, so meaby you are a bit confused with ATW power. Still - I have the graphs to prove it - they have been posted here, several times. Do a search on my user name. Saying that 6AN lines "should" be good enough for 500hp, IS missinformation, or just plain wrong - take your peak. Stock line is much smaller I.D. then a -6 line, and it works fine. Anyway.....whatever.