Quick Fuel System Questions

[femno]

Hey all,

Ive searched and read heaps but I still have some unanswered questions...

Ive been talking to someone in the know today about fuel systems, and have suggested for me to run a surge tank and 044 in my GTR. The current power im aiming for is around 300kw, for a mostly street driven car (weekender) and odd track day / drag. Chances are ill be chasing more power later down the track too.

Now it has been suggested that i change from the factory fuel line to 3/8 aluminium pipe - is this overkill? no one has mentioned much about changing it in past threads..

Planning on using the usual setup - stock pump feeds surge tank, 044 feeds rail, this means ill need to change the fittings on the rail too (aftermarket rail and FPR), worth the trouble??

And also, where should i be mounting a filter? between the stock pump and surge? or in between the 044 and the rail? (that would mean i need an expensive one with dash fittings)

Just would like to know what others are using, and whats a good idea to try and hide this stuff?

Thanks,

Mat.

[Omurru]

The stock fuel system, maybe with an adjustable fpr say a nismo one will be able to cope with 300kw but thats about max it can do. Well a 33 system at least not sure of the differences between 32 and 33 system.

For peace of mind though and what I will be doing in the coming weeks is an 044 in the tank, SARD 700cc injectors and a fpr (not sure on which one yet). standard lines can still be used with this set-up as long as your still running standard fuel pressures or close to standard, you may just want to zip-tie the lines on for piece of mind . This sort of setup should accomodate over 400kw. Surge tanks, bigger braided lines and dash fittings are not required unless your over the 500kw mark. The stock fuel rails will handle up to about 700hp so no need to change that unless you want the bling.

As to the filter this is something i haven't really looked into yet but perhaps something a bit better flowing than the standard ones may be in order.

I was originally going to go all out to cater no for future plans, but decided against it. For a street driven car in victoria at least a surge tank and pumps in the boot is asking for trouble, and isn't really required at this stage. Later on down the track you can always add in the extras.....

[femno]

Hmm well see this is what confuses me: whats the point of having a high pressure, high flow pump if the standard line can only flow so much?? (up to 300kw no more ive been told)

I guess everyone has been told or knows different figures / opinions..

Yeh i got the fuel rail - lovin the bling!

Still way :S

[Craved]

im running near 300 rwkw on std rb25 lines and rail ..

running std pump as lift pump into surge tank, then adapt into 044 then into check valve, then into std lines - even retaining the std type fuel filter in the engine bay

just replaced nearly all of the hose with better 600psi hydrolic hose

[Omurru]

I am currentley running a stock standard fuel system and making 415hp at all 4. An unrestricted line has a pretty high flow rate, my problem at the moment is at high rpm the pump can't supply enough fuel eg. it can't maintain a constant pressure at the rail, hence the need for a bigger pump/more flow, also as the pump and injectors are fairly well matched (factory spec) the injectors are at 100% duty. Hence the reason you buy bigger injectors bigger pump this means you have a blarger flow rate through the system so more fuel is avaliable to the injectors (pump) and more fuel is avaliable to the engine (injectors).

Running a higher pressure is a different story all together, at a higher pressure your injectors will supply more fuel to the engine. Hence technically if I wanted to I could just put an 044 in the tank up my fuel pressure and I would probally be alright, but I would be overworking my injectors so they would shit themselves pretty quickly. Hence the other reason you buy bigger injectors bigger pump and run stock pressure but with a higher flow rate.

Bigger lines may be required, if the standard ones can't flow the required rate. Do a bit of research, see what the max flow at standard pressure of standard lines is, if it's more than what your pump can flow at that pressure your sweet.

[femno]

So for the moment, having 300kw, the standard lines will be ok....ill probably put in the surge tank as a precautionary action for the 044 then everything should be sweet.

Correcto?

Still wondering about where to put the filter? and also what have people done to try and hide the surge tank? might build a little box to put over it...

Thanks for your help everyone!

[Omurru]

Just fit the 044 into the tank, there's a tutorial on how to do it in a 32 gtr on here in the diy section. If you decide to upgrade later go the surge tank and a couple of externally mounted 044's or something more beef I don't think a single 044 is enough to warrant a surge tank and external mounting. I am pretty confident in saying the lines can handle the higher flow rate.

As to the filter, what are the standard ones, i can't remember, have a look around and see what their flow rates are. I would be interested in this if you do find a figure If they don't flow enough just get a aftermarket one and put fitting on it to fit the standard lines and mount in standard location.....can't see there being any probs with that. a good aftermarket one is only about 200 buks and 20bucks for fittings

[`nigno]

Upgrade them its cheap and easy, I did for peace of mind... 380rwkw, 1.5L surge tank, 400hp Bosch lift pump, 600hp Holley Gravity Fed External, 45L RCI Fuel Cell, 3/8 Braided Lines, Sard 850cc's Nismo Reg and some kind of aftermarket rail... havent pulled it off to check brand, came like that when i got it.

Never EVER had a fuel issue, prior to this I ran standard fuel lines and an in tank Tomei 600ps pump and it was a friggin nightmare.

[femno]

Hmmm I think ill be going with the original idea, i was just reading the DIY 044 in GTR and it sounds like ALOT of pissing around...alot of things can go wrong and many have had problems doing it, id rather leave the stocker in there where it belongs and add in the 044 externally.

As for the fuel lines ill prob go the 3/8 later on, the factory lines will do for the time being.

benigno have you had any problems with having the surge tank visible? is your car on the street or?

[wsln33]

Standard fuel lines will be heaps big enough for 300rwkw.

[Omurru]

benigno have you had any problems with having the surge tank visible? is your car on the street or?

Just a note to remember the police are much more relaxed in qld so these sort of mods aren't so much of a problem there on a street car. If you are going to have a surge tank and external pump on a street car in vic make sure it is well hidden and use teflon braided hoses so the smell of fuel isn't evident in the boot.

[femno]

Just a note to remember the police are much more relaxed in qld so these sort of mods aren't so much of a problem there on a street car. If you are going to have a surge tank and external pump on a street car in vic make sure it is well hidden and use teflon braided hoses so the smell of fuel isn't evident in the boot.

Probably will be making a nice box to stick over it...cover it with the same stuff as my subbie box, "its part of the stereo sir" haha.

Thanks.

[Craved]

not illegal in NSW unless all the lines and tank are exposed-

if you have it all air tight, then you will be fine...

mine isnt yet, but will be once i make up a box for it all ..

[femno]

So say for instance you could build a clear perspex box for it and its legal?

Probably isnt the same for VIC though.

Edited September 20, 2006 by femno

[Craved]

So say for instance you could build a clear perspex box for it and its legal?

Probably isnt the same for VIC though.

yeah, im going to be using a stainless box with a perspex front cover - in the 33 it will be covering the entire shelf in the boot..

TWO06L run a full perspex box in their 32 GTR

[femno]

Sounds like a plan...could you PM me some pics when you are done? That would be great - i need some ideas!

Thanks.

[Craved]

pm sent

[Omurru]

Probably isnt the same for VIC though.

Everything's illegal in victoria, if it isn't they won't like it anyway and will find something else to ping you on instead.....Just need to be discrete about it

[femno]

Everything's illegal in victoria, if it isn't they won't like it anyway and will find something else to ping you on instead.....Just need to be discrete about it

Very true. No rims, keep it quiet and drive it sensibly and thats the best you can do!