jdmmax

iTrader: (6)

hi what is everyones fuel pressure with a v2 3.125 pulley.

im getting 30psi at idle and i haven't pay attention to the WOT fuel pressure cause im a b1tch and im scared to open it up.


hehehe oh i kind of drove it hard and checked my plugs and it was like a dark brownish color around the ring and the top of the ground strap was brown in color.

thanks
frank

oh by the way it drive beatiful im just a worry wart

RBa

iTrader: (2)

Mine is at 32..
You should see what you get at WOT and normal driving..

Y2KevSE

iTrader: (13)

Congrats, Frank. Hoon had to call me and ask a question about your car earlier today.

WizzaMax

iTrader: (9)

Congrat as well, Frank, I'll be seeing you soon...in my rearview...ha-ha

dmontzsta

iTrader: (8)

So you are S/C'd now?

Larrio

iTrader: (10)

dang... everyone is boosting in secret except mr. kevin. argh... must join the new trend...

jdmmax

iTrader: (6)

thanks everyone


yeah i kind of keep it on the dl just in case ish happens and it didn't go through.


but i just got a fuelpressure reading its at 30psi normal driving and at like 4-5k on the freeway it was hopeing abck and forth between like 60-70psi.


kevin hehehe thanks for the help.


dag on ething is i don't remeber this thing being as loud as it is on dennis car. is it cause the smaller pulley???
oh and the other thing i filled up gas yesterday on the 15th have 45miles on the tanks annnnnnnnnnnnnnnnd i droped about an 1/8 of a tank already. OMFG what a gas gustler.

Turbo95Max

iTrader: (25)

i think fuel pressure at idle is suppose to be 36psi....thats what i seem to remember...

Cumalot

iTrader: (8)

Yup, that's what mine was at. I had a V1 with the 3.125 pulley.

Stephen Max

iTrader: (59)

My fuel pressure at idle was at 34 psi (exactly on spec for a 4th gen) but increased to 40 psi when I installed a Walbro fuel pump.

The presence of a supercharger shouldn't change fuel pressure at idle, unless you have the Walbro pump or if you have your Hobbs switch disconnected so that your Vortech aux fuel pump is always on.

turbomax97

iTrader: (6)

mine is set at 34 psi at idle with the walbro..

Stephen Max

iTrader: (59)

You didn't need an adjustable FPR to reduce the pressure? Maybe my OEM fpr is weak.

jdmmax

iTrader: (6)

uhmmm i had a SARD fpr. left over from my nitrous kit. like they the shop took that off completly and ran everything to the FMU. shoud i put my stock fpr back on

Stephen Max

iTrader: (59)

So you only have the Vortech fmu and no other fpr? I didn't think the fmu did anything in non-boost situations. When you said you were getting 60-70 psi fuel pressure on the highway, was that with positive boost pressure or just when cruising?

jdmmax

iTrader: (6)

yes only the vortech fmu is in place. no pther fpr.
my boost gague dosn't work yet. but yeah i was kind of gunning it probably at 60-70% throttle w/OD off. and it was boosting.

turbomax97

iTrader: (6)

I have the Sard

Craig Mack

I have the exact setup as you. Walbro and stock FPR and i'm at 40psi. Should we worry?

Stephen Max

iTrader: (59)

The general consensus I got when I asked about this in the general discussion forum is that it is nothing to worry about. My EGT's during normal driving are unchanged, which stands to reason since as long as the engine is running in closed loop mode the ECU is going to shorten the injector pulse width based on O2 sensor information, even though the increased fuel pressure will try to make it run richer than before.

My fuel pressure at WOT is now at 48-50 psi (I'm still NA at present). I haven't checked my EGT at WOT yet, but I would expect it to be lower now, since at WOT the ECU reverts to a premapped injector pulse width. Since the ECU assumes that the fuel pressure is 43 psi at WOT, I am certainly running richer than before. Injector flow is proportional to the square of the fuel pressure, so if a stock Maxima is programmed for an AFR of 13 at WOT with 43 psi fuel pressure, then increasing the fuel pressure to 50 psi results in an AFR of about just over 12. (I calculated the AFR of 13 at WOT by assuming an AFR of 14.7 at idle when the fuel pressure is 34.) An AFR of 12.1 is too rich for a NA engine, but not too bad for a boosted engine.

In your situation (boosted, that is), since the base fuel pressure is raised from 34 psi to 40 psi, then your fuel pressure when boosting will be raised as well, if the formula provided by Vortech holds. So you are probably running a bit richer than otherwise. Dyno tuning or low EGTs will reveal if you are too rich.

Craig Mack

Well I'm on the 3.33" pulley with the 6:1 disc. At WOT I peaked at 65ish PSI. According to Mardi and them, that is perfect. So only at idle do I run rich, which doesn't really concern me. Thanks for the writeup.

jdmmax

iTrader: (6)

ok now that i notice it anything below 3k im at liek 28-30 psi and as i give the car gas my fuel pressure dosen't move.


when i go about 70% throttle and get int boost my fuel pressure goes to like the before mentioned:

4k 40-50psi
5k 50-60psi
6k im like at 70psi

i guess that is right im more worried about my 28-30 psi while driving normally. dosen't that seem low???

sould i put the stock fpr back in or does the fmu pretty much bypass the stock fpr.

oh and i am also running a walbao 255high flow so i am not using the aux fuel pump would that have something to do with the problem or is it noy a problem.

thanks for the help people

frank

delio

iTrader: (11)

If you have the Sard, and your idle FP is low, you should be able to raise that with the Sard. It should be just a screw you turn

there is some variance in guages, so it's hard to be sure, but I would try to raise it to the 35 PSI level for safety's sake. It should be painless to do with the SARD.

jdmmax

iTrader: (6)

hey can you tell me how to hook up my sard for back into the system?

like what goes where????

how do i tap the vacum hoses and how to hook up the fuel line.

thanks

ps: pics of the setups with a sard and how you guys connected it will help greatly.

frank

turbomax97

iTrader: (6)

i'll take pics later 2nite if no one else does... getting the vacuum line is pretty easy, you just need to tap into the vacuum lines that you used for the bov, boost guage, all those goodies... go to autozone and get a vacuum t fitting apppropriate for your setup. btw, when you get fuel line, you need high pressure fuel line, NOT just regular fuel line.

delio

iTrader: (11)

I don't have a SARD, so one of the other fellas will have to step in here.

Sexima, if you can do a write up on it, I will sticky it in this forum. Thanks, in advance.

Del

jdmmax

iTrader: (6)

let me take a poke at this seximagtr can you comfirm???


so it goes fuel rail out into the side port of the SARD fpr.
then
bottom port of the SARD fpr into the upper port on the FMU.
then
bottom port of the FMU back to the fuel retun line on the motor.

vacuum lines get tapped into the rest of the vacuum lines from the the boost gague which the FMU is tapped into which the BOV is tapped into

CORRECT????????

turbomax97

iTrader: (6)

noooo... fuel rail goes to the BOTTEM of the sard. the side port is for the INLET. the inlet connects to the OUTLET of the fmu. I'm still at work, but i should have pics up in about 4 or 5 hrs when i get off...

CalsonicSE

iTrader: (3)

There is only one adjustment for the SARD FPR which affects both idle and WOT fuel pressure. In order to keep the Walbro in check, I adjusted the SARD to get N/A 43psi at WOT, and as a result my idle fuel pressure dropped down to 30psi. I haven't noticed or felt anything strange, and last time I checked, my plugs were okay.

jdmmax

iTrader: (6)

seximagtr ever get those pics there??? hehehe just e-maail them to me if you get a chance

thanks

WizzaMax

iTrader: (9)

In preparation for my SC install, I put on the B&M fuel pressure gauge inline from filter to hose leading to FPR...

at idle ... 44 psi... revs make it jump but I have not done any tuning...

44 psi at idle seems WAY too rich and should explain my exhaust looking the way it does and mpg being so low...I am going to tinker more later but thought I would throw that out there.

jdmmax

iTrader: (6)

you have a walbaro pump right????/


do you have a FPR to tune the fuel pressure back to stock???

turbomax97

iTrader: (6)

http://www.cardomain.com/member_page...216_6_full.jpg

WizzaMax

iTrader: (9)

you take that picture with night vision goggles?

No, Frank I do not have a fpr and opted not to get one before the SC purchase...I really am considering not running the aux pump if it makes me that much more prone to too-hi pressure and getting something like the Cartech or similar...I really rather would not do so as I want to make certain all the SC parts are operable as described.

turbomax97

iTrader: (6)

night vision equipped camera