Chaotic_FC

I am sizing up my fuel system requirements, and have an important question to ask. What is the maximum CCs a 1680cc injector will flow? and at what psi will it flow that much?

thanks in advanced.

kenn_chan

I think the rating is measured at 43 PSI so it should be 1680 cc/min at 43 Lbs, could be wrong though.

kenn

2a+RoN

Yeah, they are measured at 3 bar with mineral spirits. With gasoline, what people actually run in their car, they run closer to 1800cc/min depending on which 1680 (yes, the different models actually do flow and act slightly differently). We've run them on the bench up to 100psi, possibly higher, without much issue. To increase flow by x amount, pressure must increase at x^2. So in order to double flow, pressure must be increased by four times. At 100psi, a bosch 1680 will flow approximately 2700cc/min on gas if i did my math right...

Trots*88TII-AE*

iTrader: (11)

But you're talking about a delta of 100 psi. 100 psi with 30 psi intake charge is actually 70 psi nozzle pressure.

2a+RoN

No I'm not. I'm talking about a base pressure of 100psi. With a 1:1 FPR at 30psi boost, the pressure differential would remain at 100psi.

swif

iTrader: (4)

How much power/torgue are you looking for? What is the set up?

I am also looking to up grade my injectors for my injectors to go with my setup.

I was looking at 1600cc for the secondaries and 750cc for the primaries. I will be looking to have max boost of 18 psi. I also looking for fuel pumps to go with and thought about the Apex GTR fuel pump to put out around 400 rwhp. Should I look for a twin intank set up or go with the single intank pump?

Chaotic_FC

It is a peripheral port turbo with a s475, and a 3 stage dry sump.
I am hoping to make that magic 1000 hp flywheel mark with E85.
I plan on revving no higher than 9k.
It will be running the aeromotive 13113 fuel pump with coresponding regulator, which will allow a base pressure of 100psi.
I am thinking 4 1680ccs and 2 saturated 1000ccs for primaries.

I think i have to clear my question up a little bit though. Theoretically i could double the base pressure to 6bar and see 3360ccs from each injector. However, what i am not aware of is at what level of pressure can the injector not flow any more fuel.

ronbros3

after testing injectors for about 10yrs, I found some injectors at hi pressure and hi rpm, depends on the inj. driver and some odd hydraulic phenominia, the injector does not know if it should open or close and locks in the middle somewhere and can go lean.
probably not a good thing! Ron

Chaotic_FC

yeh that would be unfortunate.

Chaotic_FC

nobody knows this?

Trots*88TII-AE*

iTrader: (11)

A) Good luck

B) Definitely will need more fuel, especially with E85

C) Without any proof or fact, 100 PSI seems pretty high for a base pressure, considering you will have to boost likely 40+ psi to hit your goal.

D) All this on a 1000hp 9-second street carbon-bodied steel-tubed FC? For your first engine build/tune? Good luck, let us know your next "project"

Chaotic_FC

(A)yeh im sure thats really funny to you.

(B)100 psi base pressure is the most that my regulator will allow.

(C)Im actually just gunna buy a body kit now.

(D)but im still building this engine, so we'll see who's laughing then.

2a+RoN

Yes, 100psi is quite high, but as long as the fuel system is designed properly it will not be an issue. There is a 1000whp supra running 6 of our ID 1000cc injectors at 100psi base and one of full race's cars is making 850whp on 4 ID 1000's at 100psi also.

2a+RoN

Did you read my above post?? I explained the math for increasing flow. In order to double flow, you need 4x the pressure. If you wanted to tripple the flow, 9x the original pressure.

Chaotic_FC

oh, that wasn't clear to me. I understand now.
thanks for your help.

ziig

iTrader: (1)

i have flowed injectors, eg Bosh style, 550 cc on a flow bench and as i raise presure I see some increase, but i noticed with pintle style inj, at about 55-60 psi they stick shut!!!! so be careful and ask you inj manufacturer what they test at, and what is its max ,before they stop working....alos a injector manufacturer will always be willing to assist you with questions no matter if it relates to them or not....just like any other company, I called a guy today about a turbo i bought from some one else and he assisted me to the fullest......

but anyway , be wary about pressures, and inclimental increase and they might or might not be tangental...

Trots*88TII-AE*

iTrader: (11)

We had some inclimental changes here, man is it cold now.

You do realize that with 45psi base pressure, at 20 lbs of boost your fuel pressure is 65 psi right? I don't see people running 20 psi sticking injectors, but I do hear of them running that kind of boost daily, so you can't generalize based on that.

And tangental? That must be a new term in injector-ology.

Chaotic_FC

[quote=Trots*88TII-AE*;9012346]You do realize that with 45psi base pressure, at 20 lbs of boost your fuel pressure is 65 psi right?quote]

I wasn't aware of that, thanks.

ziig

iTrader: (1)

i know what i want to say in my head, maybe my words are wrong, LOL
but wont that rise in PSI after boost be different to what the injector sees at the rail?
I would think 45 at the rail is safe, while whatever raise it gets due to boost is after the fact and thus holds no eefect on the action of the pintle....i may not be correct but this is what a forum is for, right , not to be embarressed but to share and learn,

ziig

iTrader: (1)

i just tested a 1600 injector at 45 it ran just about 1600, up to 55 it ran only 1700, now of course this is before boost , but if what some are saying is true then @ 45 rail pressure , boost will rise to 55 which will then make that 1600 run at 1700...

Chaotic_FC

i was always under the impression that the fuel pressure stayed constant. If the boost was raised to 20psi, then the rail pressure would rise another 20psi, and they would balance out.

Trots*88TII-AE*

iTrader: (11)

This is something I've always wondered and haven't been sure on, because on the rail side, you actively have 65psi working on the internals of the injector, and on the combustion side, you have 20 psi of charge air. I know that it sprays the same amount of volume as if it was at 45 psi because that is the difference, but it would seem to me that it would be going through the same stress internally as 65psi on a bench. I'm not an expert by any means, so I can't say for sure.

ziig

iTrader: (1)

that is what I am trying to get my head around right now!!! lol
i tested some bosh injectors at 65 psi and flow began to slow down , with a complete lock up @ 70psi....
now this is direct pressure at the common rail.......not influenced by boost or any typw of manifold pressure apart from room atmopheric pressure.....
this is why I question this whole boost will raise presure deal, I can see logic in a combined pressure rise at the manifold when air/fuel meets boost...(after rails)
but i am still inclined to believe that @ rail pressure is constant at whatever FPR is set at, thus if your injectors will cease to work at 70 PSI @ rail, then it should not be run there

however if your injectors flow best @ 55 PSI @ rails, but with boost will increase some how at the manifold, which is after the injector, it may not/ should not create a issue of injector lock.......
now here is where I cant get my head around it......if I have a low pressure at one end and high pressure at the other, I will increase flow based on pressure difference....
but....... in this case we have fuel pressure at rail side....and boost pressure at other side...but the injectors is like a valve keeping both pressures seperate, therefore when fuel enters the flow of boost it should just become a part of the flow , with maybe some increase in flow to the fuel?
i need to read up on this I hate not knowing for sure...lol

ziig

iTrader: (1)

this is the only way i can make sense of it.....

if boost is higher than fuel pressure at rail, fuel pressure needs to be increased to over come that force, and equally fi manifold is in vaccum fuel pressure will have to decrease to prevent over delivery of fuel
fuel rail pressure - manifold pressure = desired psi?
but at idle this will be much less right?
so i guess you will have to work out your base pressure for idle, and then for max desired boost?
i am not sure if i am getting this

crispeed

That's typical of Delphi and a couple other brands but not with an Indy style Bosch 1600cc injector.