Albert/ repo/ engine builders. fuel system, help!

[lind4hl]

what do you think of my fuelsystem? simple drawing in paint.

oem pump (rs2) that will feed the catch tank.
how big should i do the tank?
shouldi have all connections in the bottom or as on my drawing?
any walls inside the catch tank?


it is an6 in the fpr, too small? say 650 engine bhp

the fuelrail is an8

the external pump will be an aeromotive a1000 ( speced 700bhp on 98fuel)


what size injectors should i use for these amount of bhp?

the drawing, feel free to rework it:

[Albert]

first question,
- what is the target boost ?
- what is the fuel pressure ? 3 bar or 4 bar ?

[lind4hl]

im looking at around 2-2.5 bar boost
fuel pressure i dont have a clue, doesent that depend on what size injector/ what pressure they are working best at?

[Albert]

i would start with 750cc and 3 bar fuel press

catch tank 1.5 L

connectors on the bottom or at the lowest level at the side

[lind4hl]

all connectors at the bottom, awesome

1.5l.

my only concern is can i have my fpr after the fuelrail? heard that you can get a little wobble fuel pressure if you have it before? is this right?

[Albert]

you should have same size before and after the regulator

i would say 8AN would do

[lind4hl]

my fpr:

flow of over 2.5 Gallons Per Minute at 25psi

that would be enough?

but then i will only change the an-coupling, no probs having it after the fuelrail though?

[Albert]

if you have 8an before FPR and 6AN after than the size it self of the 6AN might be limitation the back flow to the rear tank

[AUDIS2avant]

fpr should be AFTER the rail, and catch tank is 1-1,5liter just fine m8.
All conections @ top exept to the aeromotive, this should be @ bottom.
From tank to top of catch tank
Return from rail to top of catchtank
overflow in catchtank to tank (return hose)
From catch tank to aeromotive pump in the bottom

Injectors i would choose 780cc or 850cc as minimum, @ 3bar fuel-pressure

[S2central.net]

Someone draw a picture - that will help - a LOT.

[AUDIS2avant]

hey i SUCK at drawing, dont even have a drawing program in my pc LOL

[repo]

AN6 is enough from tank pump to reservoir tank.

AN12 from reservoir tank to a1000 would be the best, but an AN10 would do, as long as it is as short as possible.

AN8 is enough for feed from a1000 to the rail.

AN6 from rail to fpr and from fpr to reservoir tank.

From reservoir tank to car own fuel tank I would use an8, to prevent pressure build up. Problem is, the original return line is so tiny, and it is not an easy task to make another return coupling to the tank...

Remember, high quality couplers have bigger diameter inner holes. Also, industrial jic couplers equal to two numbers SMALLER motorsport coupler, when it comes to flow capacity.

[repo]

Found old schematic draving I did to illustrate the components with twin 044 setup.

With a1000 You just replace the 044 pair with single big pump.

Cyan is fuel tank
brown is tank pump
black ones are filters, You need only one of those
grey ones are the 044's
green is the reservoir / surge tank, whatever You call it
yellow is fuel rail
red/white is the fpr

I always have put the return lines to the top of the surge tank.

[repo]

And yes, 780cc siemens low z (3145) is a good and cheap injector.

Remember, a1000 is a 1000hp pump, but not on high pressure. So deka006 would do for +650hp, but the pump might get on it's limits, as You'd need 4 bar static + boost. A1000 capacity starts to drop significantly over 6 bar iirc.

No baffles in the catchtank.

[lind4hl]

thank you,