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tunin' da beast
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479 Posts
Discussion Starter #1
I have a question about the fuel system. My engine is a 1.5jz and I'm considering running 650 to 750cc injectors on the stock fuelrail and stock fpr.
I'm allready running a walbro fuelpump and now I'm wondering if this would be sufficient.

If I calculate the flow of the walbro I get to:

255ltr/hr = 4.25ltr/min = 4250cc/min
flow available per injector would be 4250 / 6 = 708cc/min
considering not going beyond 80% dutycycle (as most manufact. don't recommend going beyond 80%) the calculated injectorsize would be 885cc

Will I run into any issues with this? For instance, I do not know the flow limit of a 1jz stock fuelrail. I know stock fuel pressure is 57psi.
Furthermore it would be nice to hear what max. size injectors you guys are running on the combination: walbro/stock fuelrail/stock fpr.

(This probably is covered in other threads in the past, but there's no search and with google site-search i didn't find it, so excuse me for re-asking this.)
 

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Now with 0JZ
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1,185 Posts
Stock fuel pressure is 57psi? Wow, I run my injectors at 35psi, I thought that was stock.

If it means anything, in about 2-3 weeks, I'm throwing in come 800cc injectors into the stock rail to go along with a new turbo setup. I'll make sure I post results.
 

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Not so boring anymore
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7,085 Posts
the pump wont flow 255ltr/hr at pressure...
 

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Registered
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601 Posts
Get a new fuel pressure regulator. What kind of emanage are you using? A single walbro is only good for 550cc injectors. You will need to throw in another for sure. The stock fuel rail is just as good as any aftermarket ones. If running alot of boost just run your fuel line to a tee to either side of the fuel rail and have the return in the middle. But the stock rail, the way it is, will support fuel for 700hp easy.
 

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tunin' da beast
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479 Posts
Discussion Starter #5
Thanx for the feedback guys! :)

Good to know the fuelrail won't be a bottle neck for me, I'm not planning to go beyond 700hp.

@annoyingrob, the stock pressure of 57psi is mentioned in the tsrm, I have never actually measured it. Like to see your results!

@tissimo, do you have a data sheet for the walbro? Would be good to know what it can flow at different pressure rates.

@winnipegman, so I will need an aftermarket fpr, what is the optimal pressure to set it to, or is this dependent on which injectors you're running?
And do I need an extra fuel line going to the front or is the stock one big enough to support the flow of the dual walbro's?

maybe usefull to mention a bit more of my set-up:
Greddy Emanage blue, injector + ignition harness, 3bar map sensor, AEM wideband signal feeding into this.
2jz 550cc injectors, which I want to swap out for bigger ones
avc-r boostcontroller
Apexi EGT & Oil meters (peak hold/recording)
HKS IC
PT67 A/R 0.58
40mm wastegate
tubular manifold
3" open exhaust, apexi muffler
(my avatar is my set-up)
 

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tunin' da beast
Joined
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479 Posts
Discussion Starter #7
@annoyingrob, sounds like you're a bit over the limit on your injectors there.


Can anyone tell me if I will need an extra fuel line going up front or if the stock one is sufficient when installing a second walbro?

Furthermore, what would be a good fuel pressure setting for dual walbro's and 650/750cc injectors?
 

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601 Posts
Static 40psi (no vacuum line attached)
I sure hope that only one fuel line will be ok, because I am swapping in 1000cc's soon and only plan on running one line. I will be getting the Sard top feed rail though, which I think may require me to run 2 lines. Not to sure though. Are you going to be using side feed injectors. I haven't seen many in a large enough size to support much.
 

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tunin' da beast
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479 Posts
Discussion Starter #9
OK thanx for the feedback, I will be fine with one line then.
I'll be sticking to side feed, I will need at least 650's, but if I come across some 680's or 720's that 'll be fine also. Those should be available in side feed I think.

I don't know if 1000cc is available in side feed. What are your plans in going to such large injectors? Running methanol injection as well? And what about idling, wouldn't it idle bad?
 

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Now with 0JZ
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1,185 Posts
@annoyingrob, the stock pressure of 57psi is mentioned in the tsrm, I have never actually measured it. Like to see your results!
I call bullshit on this. I just talked to a mechanic friend of mine, and he says that the 1JZ fuel pressure is 35-45psi, just like the 2JZ. I just double checked the 2JZ TSRM, and the fuel pressure is supposed to be 38-44psi on the 2JZ. I see no reason it would be any different on the 1JZ, seeing as how both motors use the same brand of injectors.

57psi is way too high.

Please, post your findings from the 1JZ TSRM.
 

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tunin' da beast
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479 Posts
Discussion Starter #13
I call bullshit on this. I just talked to a mechanic friend of mine, and he says that the 1JZ fuel pressure is 35-45psi, just like the 2JZ. I just double checked the 2JZ TSRM, and the fuel pressure is supposed to be 38-44psi on the 2JZ. I see no reason it would be any different on the 1JZ, seeing as how both motors use the same brand of injectors.

57psi is way too high.

Please, post your findings from the 1JZ TSRM.
Hi Rob, you're right, well almost then. The 57psi is during a test; when pinching the return hose the pressure should rise to 57psi.
Normal operating pressure is between 33-40psi vacuum disconnected, according to the tsrm.
 

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wasting my life on SF
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1,808 Posts
Denso makes them. All you need to do is find a supplier. There's a local HKS pro dealer here in Calgary that carries them. They're about 1300 bucks for 6 with flow testing. They sell 650, 800, and 1000cc side feeds.
if i were a rich girl shamma lamma lamma ding dog!
 

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Not so boring anymore
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7,085 Posts
[url said:
http://www.stealth316.com/2-fuelpumpguide.htm][/url]
35 274.06
40 265.10
45 259.13
50 251.37
55 244.21
60 238.24
65 231.07
70 223.31
75 216.74
80 191.66
85 179.72
90 162.41
95 149.27
100 128.37
regulators are 1:1 so 20 psi + base (43 psi) = 63 psi fuel pressure..
 

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tunin' da beast
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479 Posts
Discussion Starter #17
tissimo, thanks for the data.
I checked the website as well and that is an exellant read! I found all I wanted to know on fuelpumps :bigthumb:
 

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469 Posts
I know ManiacTechRacing sells a kit that is a top feed rail with 682cc high impedance injectors with an Aeromotive Fuel Pressure Regulator. They also sell a dual walbro pump bracket. Just thought I'd throw that out there.
 

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tunin' da beast
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479 Posts
Discussion Starter #19
I know ManiacTechRacing sells a kit that is a top feed rail with 682cc high impedance injectors with an Aeromotive Fuel Pressure Regulator. They also sell a dual walbro pump bracket. Just thought I'd throw that out there.
Thanx.
Got an url? Can't find it with google...
 
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