Jump to content
SAU Community

Gtr Surge Tank/fuel Setup

raz0r$harP.UK

By raz0r$harP.UK,
in Engines & Forced Induction

 Share

Recommended Posts

raz0r$harP.UK Grand Master

raz0r$harP.UK

Posted
Posted

Hey,

Got a couple of questions trying to streamline fuelling system for a 400kw GTR. With a surge tank, 720cc injectors, dual entry fuel rail, and braided line, it feeds off:

- GTR pump as a lifter from stock, but this appears to be mounted externally (?)

- 2x unknown external pumps from the surge to a single fuel line under the car

- T-piece splitting fuel line to twin filters in the engine bay, then to rails

- All pumps wired direct to battery via fused relays

- Standard fuel pressure 2.5 Bar

Not sure why the GTR pump is mounted that way, perhaps to wire to battery easier. From watching fuel level gauge cycle up and down, appears to be sending too much fuel around, and returning it to the tank.

Going to replace the pumps & lines for peace of mind, but also hopefully to minimise fuel smell in cabin :)

- Will a lifter pump (Std GTR/Tomei/Nismo pump) and a single Bosch 044 from the surge handle my requirements? Especially under boost (Up to 2.5 Bar boost)

- Any benefits to having two external fuel pumps running off the surge tank?

- Do I need another inline filter elsewhere?

Cheers

post-6400-1159167566.jpg

post-6400-1159167702.jpg

Link to comment
https://www.sau.com.au/forums/topic/135984-gtr-surge-tankfuel-setup/
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted

First job is to identify the main pumps, they will have part numbers stamped into the bodies. With that info I can make some exact recommendations.

In the interim, let’s assume that they are Bosch 044’s. Then it’s simple numbers;

720 cc per minute X 6 injectors X 60 minutes in an hour = 259 litres per hour

A Bosch 044 is rated at 220 litres per hour at 12 volts at 73.6 psi.

That equates to 255 litres per hour at 13.8 volts at 73.6 psi

The 73.6 psi represents 36 psi fuel pressure + boost (37.3 psi)

If you are running less than 37.3 psi (2.55 bar) boost then the pump will flow more.

So, depending on you boost level, one Bosch 044 should do the job just fine provided it is getting 13.8 volts ie; has a relay and good solid wiring to the battery/alternator.

“Normal” braided hoses tend to sweat, that’s why they aren’t used inside road cars. You can get “no sweat” braided hose from Earls. They are a little bit more expensive but that gets rid of 90% of the fuel smell problem. The lift (GTR) pump should be mounted in the main fuel tank, they are not designed for external mounting. That will remove a little more of the smell. The best method to eradicate the remainder (of the smell) is to encase the surge tank, pump and hoses in a sealed box with a hose (for fumes) vented to outside (the car).

So all that is left is for you to properly identify the main pumps.

:P cheers :)

Beer Baron Grand Master

Beer Baron

Posted
Posted

holy cow batman! when did you get a GTR?!? looks pretty serious mate. i likey.

I would think a stock GTR pump and one single 044 should be fine to flow enough for 6X720cc inj at up to 5bar pressure. the fuel smell is most likely caused by the lines breathing a little. braided rubber lines have been know to breath and smell a bit. perhaps look at repacing them with teflon line (if it's not already) or steel tube. mounting the pumps under the car is no problem providing they do not become the lowest point under there. try and tuck them up somewhere near the spare wheel well, and of course away from the exhaust. also get some better mounts than those ones on there. with rubber 'washers' between the bracket and the car body and a rubber insulator around the pump too. another inline filter would be a good idea. I'd go for an earls one, they flow lots, not much pressure drop and are cleanable and cheap.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

As SK said, need to know whats already there, you might not need two pumps :)

Although having the GTR pump externally is "interesting".

The big bosch (should you decide to go down that path) would be adequate no problem in single form.

Surely you can live with the fuel smell, it makes you more mentally alert :P

But drop the lifter back into the tank, it will as SK also said... get rid of some of the smell and a lot of un-warranted hose which is also causing the smell.

My surge is in the boot and i dont get a bad fuel smell at all, only if i leave the car sit for a week and then drive it do i notice it.

Sounds like an interesting setup Vijay

Any more details?

raz0r$harP.UK Grand Master

raz0r$harP.UK

Posted
  • Author
Posted
First job is to identify the main pumps, they will have part numbers stamped into the bodies. With that info I can make some exact recommendations.

OK just took off the clamps and they are both Bosch 979s, which from the Bosch spec sheet flows 165L/hr @ 12v and 73.6 psi.

Based on what you guys said, it looks like I could probably achieve my goals with a single 044. Just worried I guess. Is there any validity in my assumption that using 2x pumps would somehow help to prevent catastrophe in the event of one pump failing? (i.e. if one pump fails the other would provide the required flow to meet the pressure?).

raz0r$harP.UK Grand Master

raz0r$harP.UK

Posted
  • Author
Posted

Hmm.. just noticed another peculiarity.

When I compared the pic of my tank lid with one that performance-wise posted in a DIY thread, I seem to have a fourth fitting there, which doesn't look factory.

Not sure why (I haven't had time to look inside the tank yet).

I don't know why they would do that? :P

post-6400-1159939895.jpg

post-6400-1159940182.jpg

Beer Baron Grand Master

Beer Baron

Posted
Posted

with a little poking around you should be able to establish what it is. It can only really be things. either fuel return, or fuel feed (under pressure). my money is only fuel return.

Sydneykid Grand Master

Sydneykid

Posted
Posted
OK just took off the clamps and they are both Bosch 979s, which from the Bosch spec sheet flows 165L/hr @ 12v and 73.6 psi.

Based on what you guys said, it looks like I could probably achieve my goals with a single 044. Just worried I guess. Is there any validity in my assumption that using 2x pumps would somehow help to prevent catastrophe in the event of one pump failing? (i.e. if one pump fails the other would provide the required flow to meet the pressure?).

If you only have one pump and it fails, the engine stops, you know it and no lean running occurs.

If you have two pumps and one fails, the engine keeps running, you don’t know that one pump has failed, so you could have lean running and you wouldn’t know.

:laugh: cheers :(

raz0r$harP.UK Grand Master

raz0r$harP.UK

Posted
  • Author
Posted
If you only have one pump and it fails, the engine stops, you know it and no lean running occurs.

If you have two pumps and one fails, the engine keeps running, you don't know that one pump has failed, so you could have lean running and you wouldn't know.

So what would be the difference if I had, say, a single 044, and that fails (ie only partially working, providing less than full flow) - wouldn't that also result in a lean out?

Just asking as I have spoken to a couple of ppl with similar power requirements who have said to leave a second pump in there as insurance. If I have two pumps and one fails, wouldn't the second pump meet the rail pressure by pumping more fuel to compensate for the failed pump? (up to the limit of the pump)

Oh yeah, in response to my query about the extra fitting, I had a think about it and if that GTR pump is my external one (but located out of the boot), it would need the fitting to connect back through the lid to the filter sock. Just a hassle to properly look as half of the hoses run through the GTR boot bracing.. so hoses would need to be removed and I'm not quite there yet!

Sydneykid Grand Master

Sydneykid

Posted
Posted
So what would be the difference if I had, say, a single 044, and that fails (ie only partially working, providing less than full flow) - wouldn't that also result in a lean out?

Two pumps = twice as much chance of one failing. If you are that worried, run a fuel pressure gauge.

:ninja: cheers :laugh:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • 677_GTR
      R33 GTR running -9 with no tune

      By 677_GTR · Posted

      Thanks for all the replies fellas. Gonna finish putting it back together and see how it handles the set up. If it starts pinging it’ll be parked.
    • suko
      J50 clock date suddenly reset to January 1

      By suko · Posted

      Well, I can recommend the partial AV system translation CD I ordered from Car Audio Workshop in NZ. Whilst it didn't address the date issue, it has conveniently translated on-screen menu items into English, and now allows the GPS-received time to be offset in hours rather than minutes, so I can display Eastern Australian time accurately ( and bump it by another hour when daylight savings starts ).
    • GTSBoy
      Baron's R34 GT-R build thread - car in Japan for 5 years -_-

      By GTSBoy · Posted

      Yuh, if it's 45°C outside, my car is driving in it.
    • soviet_merlin
      Baron's R34 GT-R build thread - car in Japan for 5 years -_-

      By soviet_merlin · Posted

      I'd be curious to hear more. Otherwise, have you driven a modern x-trail? I wonder how it compares. Here in Australia they are/were popular for rentals and fleet vehicles. I have been in some and my impression was they are bad. But, this may have been very different in the 2000s at a good trim level. Twenty years is plenty of time to make the model worse. I do very much agree with the 2 silver cars in the garage approach. But, not driving because it's too hot would not leave a lot of time in the year for many Australians. I don't think you need to worry too much unless the car has actual issues with overheating. 
    • BaronOBeefdip
      Baron's R34 GT-R build thread - car in Japan for 5 years -_-

      By BaronOBeefdip · Posted

      Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
×
×
  • Create New...