SQUILL

Yes however the battery does act as a voltage stabalizer. Are you reading your voltage readings on the in car battery guage or with a mulitmeter?? I wonder if the regulator on the alternator is not functioning correctly.

It seems wierd the walbro fuel pump would be designed this way as any car will have fluctuations in voltage...maybe only specific to the 350z with F/I does it create a problem.

Anyway you should check the charging system with a voltmeter while the car is running it should hold fairly steady round 13.8 volts if not maybe the alternator or more specifically the voltage regulator in the alternator????

Ive had nothing but good experience with the optima bateries Im getting my stereo installed soon and wouldnt dream of being with out one.

Anyway sorry for the troubles as with any project once you fix one problem it seems another one always pops up to take its place!

Hey if it makes you feel better i am learning alot from yours and others trials and errors here!

7 eleven

GQ_626: All you need is a voltage regulator. A couple of companys make them just for this. Here's the link to the kenne bell "Boost a pump".

http://www.kennebell.net/accessories...boostapump.htm

It holds the voltage contast to the pump even if the battery output drops to 10 volts. You can also use it to increase the output of the pump up to 50%.

I forgot about this thing, It has worked good for us in the past. There is a nice feature that allows the increase to turn on at 3psi so you don't richen up the idle and cruise condtions.
Gary

pimpjuice

Boost a pump or the aeromotive DFMU.
The only problem I had with this type of voltage regulation is that I couldn't add voltage to the in-tank pump to keep it steady. Instead, they require the addition of an inline pump in which the regulators control the voltage to.

Also, TS could try something out with the ecu since the voltage to the fuel pump is controlled by the ecu.

7 eleven

The Boost a pump is not the same as the DFMU. It's just holds the voltage constant. It doesn't ramp it up in relation to boost and it's dessigned to work with in tank pumps. Check out the link.
Gary

derek_i

I like the idea about keeping consistant voltage to the fuel pump but this product kinda cracks me up. If you were using it as 7 eleven suggests (to regulate the voltage) it should work nicely.

Some of the other features however...

I think a 1:1 rising rate FPR would be a much better solution

See my point above

From their own FLOW COMPARISON chart to the right:

Stock -> 88 Boost-A-Pump -> 132 = 50%
Stock -> 110 Boost-A-Pump -> 165 = 50%
Stock -> 190 Boost-A-Pump -> 285 = 50%
Stock -> 220 Boost-A-Pump -> 330 = 50%

I'm a little wary when I purchase things, and reading something like this from the vendor immediately turns me off the product.

If an electric motor is rated at a certain performance level, increasing that can't be good for it's lifecycle.

$200 - $250 seems a little much to regulate voltage, there has to be other products that do this without the 'fluff'.

"Buy now a get a free Tornado air intake vortex unit, supercharge your car! 50-100 HP! (MSRP $39.95)"

-D

ACP

iTrader: (1)

You can run a new thicker gauge wire from the battery right to the fuel pump.
Would use somethng like 10 gauge, w 30 Amp Relay, fuse and this would give the pump a better, more constant current.

Sharif@Forged

iTrader: (92)

Witty...comments. Yeah not sure if I could sleep at night with a product called "boost a pump"...or "boost a anything" controlling my fuel flow. That company needs to get a new PR and Marketing Manager.


Spaz had mentioned that TS reflash his ECU and cured that wandering voltage thing.

Does anyone else's voltage slightly erratic from day to day? I mean...my gauge is bouncing all over the place...it just creeps about quietly, depending on conditions.


And Squill. I wouldnt know how to use a mutil-meter if my life depended it on. wanna drive over and show me?

I am totally inept in these three areas:

1) All things related to wiring and electrical.
2) Fittings, bolts, nuts, and studs
3) Typing fast with any modicum of accuracy.

Life is too short to proof read!

Sharif@Forged

iTrader: (92)

I was reading through the website...and clearly this is an issue any car with an electric fuel pump. Their tech sheet was actually very informative. We need to get to the bottom of this. Rock solid voltage is critical...even a minor drop in voltage can result in a 5-15% decrease in fuel flow....yikes! The biggest drawback to this unit is the high cost. And since I'm not interested in actually INCREASING voltage..only maintaining it at a set level, this is too rich for my blood. There must be another alternative. ACP, since I admitedly know nothing about electronic wiring and stuff, I am reluctant to run new wires to the pump. I'll keep searching and sharing..thanks everyone!


From the Bell website:


How it Works - While dyno and street testing, our On Board Data Logger told us that fuel flow was less at night when the lights, stereo etc. were on. The voltage to the pump was varying between 12 and 13.5 volts and fuel was being reduced up to 15%. Further testing in our Fuel Flow Lab indicated that by elevating the voltage to the pump we could safely increase fuel capacity by as much as 50%. The Kenne Bell BOOST-A-PUMP™ does just that - and it automatically maintains the pre-set voltage or % increase with as little as 10 volts at the battery.

greddyZ

Guys,

After reading this topic, I have become worried too because I had planned to use the Walbro 255 fuel pump with my Greddy TT setup. In addition, I have decided that I think I will run 7 psi rather than the 6 I had originally planned which means I would have to dump my stock fuel pump anyway...

So...I did some looking and found these for the 350Z:

NISMO High Flow Fuel Pump (special order from Japan I think)
- 165 liters per hour at 12 volts
http://www.z1auto.com/prodmore.asp?m...ine&prodid=925

NISMO Universal Fuel Pressure Regulator and Bracket
- Adjustable to 196 - 588 KPa at 4.0L/hr (?)
- Part Number 22670-RR710-US (Regulator)
- Part Number 22672-RR710 (Bracket)
See NISMO US Site for more details

Would these give me and you guys the neccessary fuel flow and pressure to sustain our boost levels? I feel the NISMO stuff is much more robust in terms of being correctly designed for the car since it is a factory item. Plus there is a companion pressure regulator to go with the pump. They appear on different sites but that is what I am assuming. Note - They warn that these items "void warranties" but with the state of tune our cars are (or will be in) I don't think that is really a conccern. Any feedback?

7 eleven

Sadly this is one of the cheapest voltage regulators for cars out there. The problem is the rest are designed to be used for high end audio. Here's the link for the Jacobs Eletronics one:

http://members.aol.com/rkillerbee/Jacobs/accuvolt.htm

In the literature they mention a race car version. It should be cheaper but you need to call to find out more.
Gary

7 eleven

The pump will fit but the NISMO Universal Fuel Pressure Regulator Will not fit any car with a returnless system, which is what our cars have. Our factory pump has been said to be a 140-145lph pump.So if your goal is only 7psi it may work for that limited application. I don't know where they got the 90lph rating. That's kinda low considering the factory pump has supported over 350 rwhp which is along the lines of the 140lph rating being passed around.

greddyZ

Well, is the Walbro 190 pump a better choice then? Will that pump overload my stock FPR? Please let me know. I don't think I will ever need the 255...too scared to take boost to the limits of 7 psi and beyond. Will wait to see the reliability of the engine with the pioneers here on the board!

PS - The 90 rating may be at 12V were the 140 may be at 14.4V. The 165 on the NISMO is only at 12V. The 14.4V one may be much higher. Do not know.

derek_i

This shouldn't be an issue for those going to a return system. Even at lower voltage, the 255 should be pumping way more fuel than the engine is delivering.

When you consider the cost to regulate voltage, switching the fuel system isn't such a bad idea.

-D

350Now

I was also looking at this. I was checking the Walbro flow rate chart and at 12 volts and 50psi you are still flowing 54 gal/hr = 189 lph.

SQUILL

Would this work??? Aeromotive electronic fuel pump controller.
About 250 bucks it regulates the voltage sent to the fuel pump based on load.

http://www.aeromotiveinc.com/product...uct.phtml?p=31

also read this http://www.stealth316.com/2-fuelpumpvoltage.htm
its for a stelth however it may apply as far as maintaining correct voltage to the fuel pump.

basam350z

iTrader: (1)

MSD makes a fuel pump booster PN 2350. It goes for around $200 and raises voltage to the fuel pump as the boost pressure goes up. I was reading an April 2004 Turbo magazine and it has a bunch of specs for eight different fuel pumps.

GQ mentioned that the pump is fine for up to about 7-8psi. Why not just add this on to the stock fuel pump. I'm not sure what the factory pump voltage hits at redline, but I'm assuming that it remains relatively consent throughout the RPM band. This is from MSD's site, “The amount of voltage is adjustable with a potentiometer from a range of an additional 1.5 volts to a maximum output of 22 volts over a range of 5 – 30 psia.”

On the fuel pressure regulator front, do you think we could replace the stock FPR with something like this? It’s boost adjustable.

Sharif@Forged

iTrader: (92)

I love it.....brainstorming in action...keep it coming.

As mentioned, the Nismo fuel pressure reg will not work, and that fuel pump they sell is too weak. I would just get the Walbro 190....I think that has enough fuel for about 7-8.5psi without changing regs.


Basam, that pics you posted of the boost adjustable FPR will not work in tank. The intank FPR is a POS full encased in the plastic fuel pump housing. You cannot replace it...but you could plug it...ACP is working on that solution. Also, the stock fuel pump is only good to 7psi MAX...and that is if you like seeing 12.5:1 at redline in the higher gears...it's right on the borderline of danger. I think the comfortable limit of the stock fuel pump on the greddy kit is 6.5psi, and of course, this is with timing retard on 91 octane gas.

Sadly, i think the easiest and most reliable way to get the fuel we need, is to do what ACP and SPAZ are doing...each a slightly different way. There is no SUPER easy fix...

I'm thinking of taking elements of both setups, and doing something that looks like this.

Walbro 255 in tank.
Plug the stock FPR (with ACP's special fittings he is making up)
Chop the fuel line in the engine bay before the fuel rail and dampners, and install the Aeromotive FPR. Run a rubber return line back to the plastic fuel pump assembly housing..and tap it there with an Earls fitting..or whatever....

With the stock FPR eliminated, even with a voltage dip, the Walbro 255 will deliver more than enough fuel to sustain 50psi at idle, and about 60psi at redline (via 1:1 boost compensation...that is all I need.


What do you think??

mprowe350

GQ and others,
I finally got my SARD type R regulator installed today as mentioned on my previous reply. I did not do anything with the stock regulator just left it functioning. Now the idle fuel pressure(after adjusting) is at 51lbs instead of 74lbs previously.

It is working correctly b/c I see it holding at 59lbs with 8lbs boost at 6000rpms.(previously had dropped to 50 lbs at that same point) Now I am ready for the dyno on wed or thurs. I will post some results and hopefully won't be lean up top anymore!

Really easy to do took about two hours labor and an hour searching for pipe fittings at Lowes.

MIKE

g35tt

gq_626 what did the car dyno at??? i will like to know some info couse i am installing a greddy tt on my g35 so i was just wondering what u made?

Sharif@Forged

iTrader: (92)

Great work....please post some pics of the installation..I wanna see how the fittings look. Good work..that is exactly how you want your fuel pressure curve to look.