needless to say I got tired of waiting a week evey month to post so I went hoofreakinreah. any way, Im am hainvg a bit of a problem with my fuel issue On my turbo. I am going to be running 10psi and look to be making around 250 (ruff estimate) and I need to figure out what to buy with out going over. so far Im thinking of buying an safc to fine tune my vortech fmu. and for the wideband a plx 250 or 300. as for the brawn behind the brains Im thinking about buying just new injectors like 350cc.
no for a few questions (in list form for your enjoyment)
1. I am under the impression that the difference between the plx 250 and 300 is that the 250 is a guage and the 300 is on the box. and also I read that the the 250 has datalogging software.
2. Is it possiable to just buy a different guage with data logging and stick it on the 250. if so does anyone know of anyone.
3. I plan on buying injectors and I am looking for the cheapest ones I can get my hands on. now before you say it let me explain. I have seen injecotrs from rc and accel for upwards of 400 dollars thats fine and if I have to end up paying it I will. but I have heard of people useing dsm's and other car injectors. I have a feeling that these will work just fine and are probably alot cheaper, not to mention that I live less then 5 min from a junkyard. also if this is true is there any adaptation problems
4. finnaly(unless I can think of some later) does anyone have the corealation of lbs to cc of injector. im trying to get a 1:1 thanks.
see what happens when non premes have to wait to post!!!!
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Kick azz is my boost hero!!! 
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1. Not sure, you can check up on that on the PLX website.
2. I think it needs the PLX gauge to work, the datalogging is built into the brain box, not the gauge.
3. Depends on your engine, Ford Red Tops and Brown Tops are popular choices.
4. lbs * 10.5 = cc/min ..... cc/min / 10.5 = lbs/hr
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ok where can I get ford reds and browns and what CC are they. also do you know at what HP the stock fuel pump is good up to.
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Kick azz is my boost hero!!! "
heres where i get a bit in the grey area. now I belive that the stock eco pump is at 50-60 and can jump to like 75(psi of course). now how does hp work with FP. becuse heard of guys at 230hp not gettting over 100 psi. so how do I give an estimate of fp needed.
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Kick azz is my boost hero!!! "
I just checked ebay and those injectors (#30 for red top injectors from a mustang or somtehing like that) for 100$ is this right why would anyone pay 400 plus if these things work just as well. is it a name brand issue like most other things. also you said pic up the clips your toalking about the clips that hold the injectors. and what kind of modifaction is needed to make these work.
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Kick azz is my boost hero!!! "
You estimate fuel pressure using the size of your injectors and estimated fuel pressure (calculations are discussed extensively in my FAQ at the top of the page).
Ford injectors work just fine, sometimes it is a name brand issue, sometimes its having more choice. Obviously RC makes more than 2 sizes of injector.
By "clips" I mean the wiring harness "clip" that attaches the injector wires to the injector. You will need to cut your existing clips (also called pigtails) off the stock injectors and wire these in. The injectors will work with the stock holders (metal clips to hold the injector to the rail), at least it does on my 2.4.
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ok So I plan on picking up the redtops. ill make sure to get the clips but one last Q how will I know what wire goes where when wiring the injectors I know that there are only lik 2 or 3 wires but they different colors for difernt injectors (i would imagine) so is there any way of knowing what to hook up. and is that all there really is to new injectors just plug and play. injector in cut harness free of injector wire new one and done.
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Kick azz is my boost hero!!! "
Basically yes. What side you put the wire on (there are only 2 wires per injector) doesn't matter as long as you keep the same wires with the same injector (don't take a wire from injector 1 and use it with injector 4).
Its basically plug and play, although with bigger injectors you will need to turn your fuel pressure down so it idles correctly (hence the need for an adjustable FPR).
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will these red tops wok on my z24? and do you know close what cc they are
I have to just clearify this one more time. all redtops fit my eco. they are all generic?
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Kick azz is my boost hero!!! "
ok back to the Q's you said that fuel pressure is directly related to HP and injector sise. I cant find fuel pressure math any where
I know that you said that the stock Fuel pump is no good for anything other than stock but I was looking at a post where a member said that he was only at 100 psi MAX at 230. now I know that there is a curve and numbers arent linar but how high could psi stay at 200 to the wheels. I think I just need the formula can you help me out.
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I was just thinking of something that scared me. if My fmu is set to 12:1 then at 10 psi will my fuel pressure be 120 psi more then sotck if so I am officaly scared.
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Kick azz is my boost hero!!! "
^ Yes, which is why I HIGHLY RECOMMEND not using a fixed rate FMU.
Directly from the FAQ wrote:
Well, the first thing you need to do in order to plan your fuel injector setup is to determine how much power you plan on making. This has to be a realistic number, you are never going to get 250 BHP from 10 PSI out of the TD04 on your 2.2 OHV. Take a guess at what your horsepower is going to be.
So lets say I think my max horsepower is going to be 225 BHP. There is a real neat formula that will tell you a basis (note, basis, not exact) for what size injectors you need.
IFR = (HP * BSFC) / (# of Injectors * .8)
IFR is the Injector Flow Rate in lbs per hour
BSFC is the Brake Specific Fuel Consumption. A good number to use is .55 for NA, .65 for boosted engines.
# of Injectors are the number of equally sized injectors you will be using.
The .8 number is the maximum duty cycle of the injectors. You can't run injectors at 100% all the time, they will heat up and burn out. .8 is the highest duty cycle that you should use, which is why you don't want to use stock injectors.
So, my 225 BHP car, with a BSFC of .65, I will use this formula:
IFR = (225 * .65) / (4 * .8)
IFR = 46 lb/hr, multiply that by 10.55 to get CC's, 485cc
Now, those are some huge injectors for a 225 BHP car, yes. In fact they are too big. So why use that formula? Well we need a basis, that is how much fuel the engine should be using at the horsepower peak. The formula above assumes you are going to be running your fuel system at 45 PSI, which you won't be.
So, lets say we want to see if we can get away with some 36 lb/hr injectors. Lets say we are running 60 PSI at the HP Peak. You can use this formula to figure out what the fuel injector flows at a certain PSI:
F2 = (P2 * F1) / P1
F2 = Flow (in lbs/hr) at the new PSI
P2 = Desired fuel pressure
F1 = Fuel injector flow at the rated PSI (P1)
P1 = Rated fuel injector PSI
In our example:
F2 = (60 * 36) / 45
F2 = 48 lbs/hr
Wow, at 60 PSI, the 36lb/hr injectors will outflow the 46lb/hr injectors. As an added bonus, higher fuel pressure means the fuel injector doesn't need to use such a long duty cycle, has better fuel atomization, and improves injector life. On the down side, too much fuel pressure will cause the injector to "clip", or not provide any fuel. This is the problem with just increasing the fuel pressure on stock injectors.
Theres all the math you need to figure out what your fuel pressure needs to be to support X horsepower.
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is there a way to regulate the pressure so the fmu can only go so high how are other people getting away with this.
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Kick azz is my boost hero!!! "
one more thing. is a soloution to possiable let the pump max it self out. say its max is 110 psi and the fmu has it running that. but I use my safc to regulate the fuel to the injectors.
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Kick azz is my boost hero!!! "
sorry man one more thing. what regulates fuel pressure I understad that hp is directly related, but then what is the point of something to rasie it. wont my comp rasie pressure. i am confuesd
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Kick azz is my boost hero!!! "
ha thanks yeah I guess I got a bit more reading to do.
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Kick azz is my boost hero!!! "
