rx7xr8

need t know if the standard intank fuel pump in my 88 FC turbo will supply enough fuel for a Bosch 044 700hp external pump knowing the standard pump shouldn't be under pressure cause the Bosch external will be producing the rail pressure? i'm only running basic mods ,more fuel is one of the many upgrades i need to keep my rota runnin, not aiming for big horsepower at the moment, (bout 300rwhp), but mite as well get something decent for possible later hp increases. any proven knowledge & advice would b much appreciated

X-JaVeN-X

why not just get an intank replacement like eeverybody else?

Osirus9

iTrader: (10)

that pump is WAY overkill for your setup. and you would definitely need to get an FPR to control that monster. an in-tank pump will do you just fine, like a walbro or a supra pump.

RETed

Don't exactly know what you're trying to do?

Surge tank set-up?

Dunno where that "700hp" came from, but the 044 might support around 500 on a rotary...


-Ted

rx7xr8

The "700hp " figure was from some advertising blurb, not my idea, i know it's overkill for 300rwhp but like i said "something decent for later horse power increases" the main reason is my mate got it for me for free ( paps he didn't realize there was an intank equivelant) so why wouldn't i try make it work. i know of at least 1 popular car manufacturer who used a lower pressure intank pump supplying a high pressure external pump, thought i'd put it out there to see if anyone tryed it on a FC without using a surge tank. already got the adjustable fpr fitted

cpubugs

I wouldn't say it is an intank equivelant, but there are intanks that will more than satisfy your motors thirst.

hIGGI

iTrader: (7)

YES

I run Bosch 044 with surge tank and that tank is fed by stock TII pump in the stock fuel tank.....

around 1 bar of boost on GT35R

RETed

You can't do that.

Wait, let me rephrase that...

It's a stupid idea to try something like that.


-Ted

rx7xr8

O.K."RETed"could you perhaps elaborate on why my idea's so stupid, obviously i would like to know, that's why i posted the question in the first place, i like to understand the reasons why my idea's are stupid. Thanks "hiGGI" that looks more helpful, so if the standard intank pump can supply enough fuel for the 044 using a surge tank, could it all work without the surge tank, maybe? i'm obviously ignorant here, but i'm just trying to keep it as simple and cheap as possible... Thanks

hondahater

iTrader: (2)

why don't you do a search in the single turbo section and there is a fuel sock that you can get for the 044. It's a bit pricey but if you got the fuel pump free or cheap (you bastard I can't eve get one, first place ripped me off and the second guy I bought it from on the forum is flaking on me) then you shouldn't mind buying the sock for it and just putting it in your tank.

edit: here you go http://www.jayracing.com/index.php?m...products_id=62 and if your to cheap to buy a 50 dollar piece for your car then you need to sell the car to me

rx7xr8

Sock sounds interesting, i thought the internal & external pumps must be different , otherwise they would just promote one pump with multifit internal/external fitment purposes. i've seen Bosch 023 pumps which are advertised as been the intank equivelant to the Bosch 044 on ebay and they have an open intake base instead of a screw fitting intake base. i have heard of some pumps being push or pull types, if thats relevant

RETed

Okay, there are two ways to run dual pumps (with no surge tank)...

1) In series...
This means that the fuel pumps are run back-to-back.
The output of one fuel pump is run into the inlet of the other.
If you do this, the lesser fuel pump acts as a RESTRICTION.
Because the smaller fuel pump cannot pump as much fuel versus the bigger fuel pump, this ends up as a restriction.
You're better off just running just the one bigger fuel pump!

2) In parallel...
This gets more interesting...
But, because you're not using two identical flowing fuel pumps, you run into a problem called inversion, where it's possible the larger fuel pump will actually start to pump fuel into the smaller fuel pump, hindering proper fuel flow to the fuel injectors!

This is why it is NOT recommended.
The proper way to do this is to use a surge tank system.


-Ted

hIGGI

iTrader: (7)

without surge tank it would not work as pointed out by RETed, stock pump would work like restrictor.....

and dont forget, that surge tank is fed by TWO streams (by stock pump from stock fuel tank) and it gets fuel from return fuel line (from FPR)

rx7xr8

Thanks for explanations guys,i think i'll have to think more logically before i make my idea's puplic, i haven't had anything to do with surge tank systems and didn't realize the injector rail fuel return line was plumbed into the surge tank therefore helping the standard pump keep up with the extra demand of the bigger pump. excuse my ignorance... thanks for your help.