Limit Of 2 X 044's On E85

[T04GTR]

JUST A QUICK SIDE NOTE, the "pre pump" ie the the one that fills the surge tank must outflow the main pressure pumps or you will run into trouble.

2 044's/ put a carter or holley blue in there instead of the stock pump..

the size of the surge tank has to be big enough to sustain the main pumps for less than 10 seconds. and the bigger the lift pump the smaller it can be.

as for smell. teflon or solid lines are the only option for no smells. evan under the car. because you now have double or three times the length of hose leaking smells.

[Strik3r]

well thats hardly true. your lift pump will hardly ever outflow your pressure pumps. consider that 2 044's are going to be flowing a combined total of somewhere over 400 litres an hour (each should be good for at least 3.5litres per minute). Pretty sure a carter pump is only about 300 l/hr. The point is that the fuel that is unused returns to the surge tank. As Hyped6 was getting at a few pages ago, you need to work out how much fuel your engine uses, make sure your pressure pumps can supply it, and make sure that your lift pump flow + surge tank volume can provide enough fuel to the pressure pumps to last for whatever the car requirements are. Track cars obviously will put the highest demand on the pumps, whereas drag cars only have to last for 10-15 seconds WOT.

Edited November 21, 2010 by Strik3r

[JonnoHR31]

a good way test roughly how long your setup can last at 100% inj duty is to pull the return line off in the engine bay and drop it in a bucket, start the car and let it idle and time how long it takes for the surge tank to empty. obviously this isnt going to be perfect as things are slightly different at WOT but it gives you an idea

Edited November 21, 2010 by JonnoHR31

[Piggaz]

a good way test roughly how long your setup can last at 100% inj duty is to pull the return line off in the engine bay and drop it in a bucket, start the car and let it idle and time how long it takes for the surge tank to empty. obviously this isnt going to be perfect as things are slightly different at WOT but it gives you an idea

I will do that very soon. It will be easier to see what an 044 pumps the my Nismo lift but they flow almost the same. I WILL return with the results

[Piggaz]

You MUST run a far bigger return from the surge tank to the main tank or your going to pressurise the whole system which is what happened to Pupsi.

Imagine you have a stock pump as a lifter and 2 x 044s after your surge tank and your engine is at idle.......you have about 6 liters per minute of fuel from the main tank just flowing through the surge tank keeping it flooded, with that pump alone there may be "very slight" pressure in the surge tank even if the return is the same size as the feed.

At idle your engine is consuming very little fuel so its not using much of the 6 liters per minute the lift pump is supplying and most of the fuel your 2 x 044s are flowing is comming straight back to the surge tank.

Your return from the surge to the main tank is already being used to capacity to keep up with the 6 liters per minute the lift pump is supplying so how is the extra 10 liters or so per minute from the engine suppose to get back from the surge tank to the main tank without creating pressure?

Robbie.

That there is quoted from Robbie from RIPS off the pommie forum. Similar thread!

I suppose a cheap way around this is throw another -6 fitting in the surge tank and run 2 return lines back to the main tank.

[JonnoHR31]

main pumps are irrelevant in that regard. aslong as your return flows atleast the same as your feed from the main tank then you wont have any problems.

my return is the same size as the feed and i havent had any issues with pressure

[Jap_Muscle]

So what you guys are saying is that the fuel pump that fills up the surge tank needs to be bigger then the pumps fueling the injectors?

Ive currently got a bosch 023 supplying fuel to my 2-3L surge tank via a -6 line which is all inside the boot. The Surge tank then leads to 2x 044s under the car via -8 lines which leads to a twin entry fuel rail which is also via -8 lines. The car is purely a street/drag car.

Will i run into fuel smell with just the surge tank in the boot? What brand fittings do ppl recommend to combat the fuel smell?

also i see alot of ppl are running 2000cc injectors. Im currently running 1000cc. will the injectors max out before my 044s or even the turbo?

Im on a fine line with the mrs since the suspension upgrade. If i tell her she has to smell fuel to i might have to sleep on the couch for the next few weeks

Edited November 23, 2010 by Jap_Muscle

[JonnoHR31]

So what you guys are saying is that the fuel pump that fills up the surge tank needs to be bigger then the pumps fueling the injectors?

only if you want to be at WOT for long periods of time. all you need to make sure of is that your intake pump flows enough and your surge tank is big enough to ensure you never empty it. best practical way to do it is, pull the return line off in the engine bay and feed it into a bucket or jerry can, start the car and let it idle and time how long it takes for the surge tank to empty. take off a couple of seconds and make sure your never at WOT for more than that long.

if your doing circuit work it'd get more complicated as the surge tank might not fill back up all the way between squirts

[Jap_Muscle]

what exactly do you guys define as long periods of WOT? and in what application?

ill be at the very most on WOT at 10-14seconds at time so i hope the surge tank is big enough and the pump supplying can keep up.

but my biggest concern is the smell of fuel. can anyone answer if mouting the surge in the boot will be a problem? or should it be under the car along with the pumps?

[R31Nismoid]

If you buy proper insulated lines, it wont be a problem (they are not cheap, you'll be spending quite a sizeable sum probably around 300-500 just on the hose IIRC)

Normal fuel hose will weep, always does.

[Jap_Muscle]

Is there a particular brand of lines ppl recommend?

[Jap_Muscle]

im just not 100% sure what are proper insulated lines. How do teflon lines compare to aluminum? what advantage does teflon have over aluminium to justify the extra price? Do people prefer speedflow stuff to earls? or any other brand?

[Jap_Muscle]

after having a chat to the guys at speedflow i ended up taking the plunge on the twin 044s as well. heres some specs

2-3L Surge Tank in boot

2x 044 bosch fuel pumps (mounted under car)

1x Bosch 023 Fuel pump (lift pump)

Teflon speedflow fuel lines and fitting in engine bay and boot

Aluminium speedflow fuel lines and fitting under car

10.5mm Twin entry Greddy Fuel Rail

SARD 1000CC inj

Tomei Type R Fuel Regulator

gt35r .82

should be finished by in a week or 2. i doubt ill hit the limit of the 044s but some numbers wouldnt hurt.

I also noticed alot of you guys are running 2000cc injectors. Will my 1000cc injectors be sufficient for my turbo size? Also can modifications be made to my existing 10.5mm fuel rail to accommodate a upgrade to the 11mm ID2000s?

Edited November 24, 2010 by Jap_Muscle

[Piggaz]

^^ in regards to the % duty on 1000's I sailed past 50 % duty of my ID 2000's VERY early on into the tuning process.... I didnt take much notice of what the Duty was at the end of it but personally I would be putting in the 2000's in.

[R31Nismoid]

Pretty sure teflon lines still weep as they are not the high end stuff...

someone can confirm but i remember reading a post about it all

[T04GTR]

wrong!!

TEFLON OR HARD METAL PIPES are the only way to go for no smell.

(btw most of the really hi end hoses like xrp 79 and pro-gold teflon are a more flexible hose than the regular pure teflon braided stuff that use an olive to terminate)

[180or200]

I got my fittings and teflon hose from this guy, no smell !!

http://stores.ebay.com.au/Torques-U-K?_rdc=1

[R31Nismoid]

wrong!!

TEFLON OR HARD METAL PIPES are the only way to go for no smell.

(btw most of the really hi end hoses like xrp 79 and pro-gold teflon are a more flexible hose than the regular pure teflon braided stuff that use an olive to terminate)

Fair enough then

[T04GTR]

well thats hardly true. your lift pump will hardly ever outflow your pressure pumps. consider that 2 044's are going to be flowing a combined total of somewhere over 400 litres an hour (each should be good for at least 3.5litres per minute). Pretty sure a carter pump is only about 300 l/hr. The point is that the fuel that is unused returns to the surge tank. As Hyped6 was getting at a few pages ago, you need to work out how much fuel your engine uses, make sure your pressure pumps can supply it, and make sure that your lift pump flow + surge tank volume can provide enough fuel to the pressure pumps to last for whatever the car requirements are. Track cars obviously will put the highest demand on the pumps, whereas drag cars only have to last for 10-15 seconds WOT.

i do know how to plumb...

im talking in a perfect setup. not a half-way backyard track hack setup. take a look at the gibson gtr fuel system. all that to supply a hilborn mechanical fuel pump.

if you could stick to cheap walbro's in the tank to fill the surge that would cover 99% of the street cars out there. and in most cases trying to fit a 3+ litre surge tank under the car isnt easy.

and if you are one of those who is worried about weight, running a skyline at 1/4 tank at a track day is a big ask.

[Jap_Muscle]

^^ in regards to the % duty on 1000's I sailed past 50 % duty of my ID 2000's VERY early on into the tuning process.... I didnt take much notice of what the Duty was at the end of it but personally I would be putting in the 2000's in.

Exactly what turbos are you and N1GTR using? sounds like some serious gear, how big are the cams?

What clutches are holding down the power? have you noticed it starting to give way?