Fuel pumps

[JimX]

Well, I was mostly thinking that if somehow the clamps fail and the pump drops off and lands with the positive terminal on something metallic in the tank. When you say "its all earthed and plastic" do you mean the interior of the tank? If so then maybe I'll just forget about it

[predator]

well i was wondering about that myself.. exposed negative terminal and while that rubber boot looked fairly shielded, wasn't full enclosed.. and water is a conductor so i assume petrol is similar?? anyway, it doesn't so i guess its all been figured out. Probably the current is too low.

when i first turned the engine over i was a bit nervous, but after that guess it didn't exploded so it was ok

yes... AAC valves can become stuffed ..something to look into.

[Steve]

The amount of fuel vapour and lack of O2, its not going to ignite - i actuall tried to 'blow up' a lawnmower petrol tank once, but couldnt get more than a flame out the top - it didnt go into the tank itself even though the tank was nearly empty - quite frustrating.

From what I could see, the whole pump, electrics and tank are all insulated from eachother - plastic everywhere. I didnt even bother putting the dust boots on the pump when I installed it as I couldnt see any real purpose apart from protecting from dust:D

[benm]

Interesting topic and a nice bit of reading...

Are there any disadvantages of using an aftermarket fuel pump when its not required? ie worse fuel mileage etc, etc.

What I mean is the standard R33 GTS-T pump is rated to '300bhp'. Now im not sure what 300bhp is in rwhp but im guessing it would be around ~250rwhp which is about ~190rwkw (am I even close??).

Now @ 7psi (~190rwkw) power delivery is perfectly smooth from 0km/h through to 190km/h but @ 12psi (~203rwkw) it sorta surges alittle when i put the foot down and pops n farts alittle for afew seconds, its certainly not smooth.

Im not using any aftermarket engine management except the standard ECU (waiting to go the full hog to a PowerFC) but I know eventually i'll need a bigger fuel pump for future mods anyway.

Would increasing my standard pump to say a Nismo RRS40 (175% more than standard so around ~525 bhp) for $325 fix this problem.. cause any other problems etc etc?

I'm not mechanically minded but just trying to learn using the info from this site.

[JimX]

A bigger fuel pump will increase your fuel pressure slightly and you will run a bit richer. That's why I'm getting my S-AFC re-tuned tomorrow, to compensate.

[predator]

What I mean is the standard R33 GTS-T pump is rated to '300bhp'. Now im not sure what 300bhp is in rwhp but im guessing it would be around ~250rwhp which is about ~190rwkw (am I even close??).

Sounds about right. Thats the thing, most people only worry about a larger fuel pump when they go whack a bigger turbo on the car, but I think there is benefits to running a new pump at around the 80-100,000km mark when you're getting around the 180rwkw mark and want to squeeze maybe that extra 10rwkw out.

Not only is the stock pump going to maybe be slightly worn over time, and probably pumping less efficiently, by running higher boost, etc and hence working harder you are probably reducing its operating lifespan a fair bit.

The way i see it, replacing the stock pump is definitely not going to do any harm, and may help fix a lack of smooth power across the range. You may get reduced economy, but with a retune the difference should be negligible.

Mine sometimes (although not always) feels a little flat when i put the foot right to the floor, even though its been tuned pretty well and i've tried cleaning just about everything else. Most tuners I've been to just go "hmm, dunno..could be this could be that" so always best to eliminate one from the equation. To me, it just feels like it "should" but its not quite...esp when trying to run high boost (around 12-14psi)

[GTS-t VSPEC]

I don't want to dredge up an old thread, but I'm planning on a fuel pump upgrade soon, as I'm pushing the limits of the stock pump already by running higher fuel pressure.

I was planning on buying a pump and mounting it externally (inside the boot) with a surge tank, and having it supplied by the stock GTS-t pump.

Has anyone done this? Or can anyone see any problems in using this method?

[JimX]

Plenty of people have done that, and I was contemplating it myself. The only real problem with this setup is the extra noise and loss of boot space. If you think you can cope then go for it.

[GTS-t VSPEC]

I'm not too concerned about the npise, it would be hard pressed to overcome the exhaust note, and I was planning on putting it in the space next to the battery in the boot, so no space lost either:D

I was just concerned about what happens if the stock pump shits itself. I know that it won't have to work very hard as the external pump will do most of the work, but wasn't sure the impact it would have it it stopped working.

[JimX]

The impact would be no less or more than if the pump died without a surge tank. Your engine will splutter and lean out, hopefully for not too long! I'm not sure if the stock fuel pump will flow fuel through it if it's not running. If it does then you might not even notice that it's not working.

[Brody]

I had my 044 popped in by Hills in under an hour.

The only problem i have is,

a. is it a 044 or a 040. Every1 says that the 044 is a bigger job, and mine went perfectly smooth, so uum yeh

b. i get that shit circulating sound. every 30 seconds or so u hear the fuel squirt back into the tank, be it 1/4 or full, and makes the car vibrate. It can go 5 minutes without doing it, or it may do it every 30 sec...Any advice?

[JimX]

Brody, who did you speak to at Hills to put the pump in? Marcus didn't want to do it when I inquired.

My pump doesn't make any weird circulating noises except for when the fuel level is below the level of the pump. The fuel must absorb the sound when it's above this. But I get no vibration at all and you can't hear it if the stereo is on.

[Steve]

Brody, my advice would be pull the pump out and have a look.

Mine does not make that sort of noise, even when my tank is almost empty - I would be a bit worried sorry to say.

[Brody]

meh ****.

I tried taking it apart on the weekend though i couldn't get the screws out of the 2nd part, none would budge with a screw driver...I'll try some more with a drill perhaps...

Marks told me its a 044,

And Steve put it in, don't think markus was around when it went in...

Despite me not driving for another 1 1/2 weeks (lic. sus.) im now waiting for a nice big bang! argh.

[JimX]

Brody, how low have you run the tank after you got the new fuel pump put in? Mine now runs out with around 8 litres left in the tank (the gauge needle is just below the Empty line). I keep meaning to get it to around that level again so I can pull the pump out without having to dip my hands into petrol and extend the fuel pickup down further into the tank.

But everytime I go to do that I need to drive a long distance on the weekend so I have to put more fuel in. Maybe next weekend

[Brody]

Well i havnt really been driving much of late so im not to sure

I try to not let it float past 1/4 much anyway...This is going to shit me until its fixed now.

[MattyB]

steve, reading what you were saying about the hose size going onto the banjo fittin, would this mean that the standard fuel hose size might be too small ? you said you used 3/8 hose, im guessing this is about the same as a -8, where most fuel lines are -6 (i think, not with car atm to check).

ive just bought a 044 to install. would it be worth running a earls hose from the tank in -8 under the car (mount the ss hose in a alloy pipe while under the car) then up the frount thought filter before entering the fuel rail. in that situation i would also need to mod the fuel rail to take the larger fitting size.

anyone got any thoughts on that one?

[Steve]

I think it is about 10mm or there abouts anyways. It is only required because the banjo fitting was too big for the smaller stock hose. From memory,the stock hose from the fuel pump to the top of the tank is already 8mm.

I dont know if it would be necessary to use upgraded hose from the tank unless you were running massive pressure? Alot of guys here take rail pressure alot higher than stock and still dont have trouble with leaking lines.

[MattyB]

i wasnt so worried about the pressure. these lines would be made to with stand leaking after a crash. which would mean that in general operation they would be fine. the only thing i was thinking about was if the flow capacity of the line would equal that of the pump. another thing im looking arround for is a high flow fuel filter. i figure if im going to get the most out of the pump i should plum it to its full capisty. (not that i need that ammount of flow, but easy to do it once and do it properly)

[Steve]

MattyB, sorry I have no idea where the flow efficiency of the standard fuel lines starts to deminish. I did a bit of research into fuel system to support 600+hp, and not once was I advised that the fuel lines would need upgrading, just injectors and pump.