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Old 07-31-2012, 09:00 AM
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Default Heui injectors

So Im kinda tired of being in the dark on all this. I.understand the baisics of how they work, I guess I get confused when people start talking about pulse width and every thing else. I can't remember if it was HRT that posted a graph when guys were talking bout big ass injectors and I had no clue wth I was looking at. People also say there are problems getting fuel in quick enough and I guess I don't understand it enough to even have a clue. Teach to me!

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you have entirely too much time to whack off.
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Old 07-31-2012, 09:09 AM
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I moved this out of the classifieds.

I was just thinking in the last day or so that we have not had a real good technical injector thread over here yet - at least not like the 20-30 page threads we had over on the other site back in the day.

Give me a few minutes and let me rip some of my old posts off another site to begin discussion here.
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Old 07-31-2012, 09:10 AM
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It was in classifieds? Damn fat fingers on a small phone. Much appreciated

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you have entirely too much time to whack off.
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Old 07-31-2012, 09:13 AM
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One post.... not in any particular order...

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Originally Posted by HotRodTractor View Post
Disclaimer – I’m in the fields making hay and didn’t devote a lot of time to this…. I think all the numbers are correct but if you find a math error – well that happens – this is more about the concept than anything.

Ok guys – it seams as if there has been some confusion about injector oil consumption and I hope that the following series of posts will help shed some light on this. Starting out I’m going to go slow and keep it simple and build upon the concepts. All of the data starting out here will be best case scenario and in the real world is subjected to inefficiencies inherent in each of the subsystems

Lets start out by looking at a simple set of 238cc hybrid injectors with 80% tips. Here is a graph showing the fuel injection for these injectors based upon ICP and PW. As a standard disclaimer these injectors were flowed using a “Gen3” style gear pump coupled to an electric motor spinning at 1750RPMs???? – I think. This will become important later and will fill in more details.



Ok now comes the simple part – we know that it is a hybrid injector and that for every cc of fuel expelled the injector HAS to use 5 times that volume in oil. Picture the above graph with the volumes multiplied by 5.

Now using this data we have the actual oil consumption for the injectors – now lets take a closer look at pump used to produce these actual flow rates – remember I said these numbers were produced on an injector flow bench running the same basic gear pump that is used on the Gen3 system – that is 0.61 c.i. per pump revolution or for those metric gurus 9.99cc per revolution – since the pump is spinning at a known 1750 RPMs (I need to verify that…) we know its flowing 17482cc of oil per minute (or 4.71 gallons per minute). For arguments sake I want to convert this oil flow rate to something that we care about, say a standard 17* pump that displaces 7.2cc per revolution. Straight up we get to 2428 pump RPMs. Considering the pump on a PSD (single stocker lets not complicate things further….yet) turns at 85% of the crank speed we get an engine RPM of 2856 RPMs. If you take into account some inefficiency in the system, we will just round it to a nice clean 3100 engine RPMs to produce the same result as found on the bench. (RPMs get rounded up due to inefficiencies because of the reduced the cc/rev that the pump puts out).

Now here comes the rub – suppose you want to run that 3.5ms of PW at 2000 RPMs and 3000psi - you might not be able to do so…. How about at 3500 RPMs? – now that is still possible….. Let me elaborate a little….

We know that the 17* pump WILL work at 3100 RPMs because that is basically how these injectors were tested. At 3100 RPMs the 17* pump will produce 4.71 gallons per minute. At 3500 RPMs that 17* pump will be putting out 5.15 GPM (considering inefficiencies). That is more than enough to supply the injectors based on the flow sheet – in fact the duty cycle of the IPR will be lower to be able to achieve the required pressure than it was at the lower RPMs.

Lets look at 2000 RPMs – the 17* pump can only supply 2.94 GPM at that RPM! Now you ask – “But is that enough for these injectors?” Lets find out that answer. We know we want 3.5ms of PW and we want 3000psi – a quick lookup at the graphs and that determines that we want to inject 238cc of fuel (per 1000 shots for those that do not know). This means that we need 1190cc of oil per 1000 injection events –or- 1.19cc of oil for one event. This event takes place in 3.5ms. This gives us 1.19cc of oil in 3.5ms… that right there is a flow rate. There are 12 crankshaft degrees per millisecond at 2000 RPMs – or 42 degrees of crankshaft rotation – or 35.7 degrees of rotation of your 17* oil pump. So 1.19cc per 35.7 degrees of crankshaft rotation is 12cc per pump revolution! Guess what – BAM P1211! That pump will NEVER keep up at that pressure with tuning that calls for fuel like this. In fact at that RPM I would be surprised if that 17* pump keeps up calling for 1000psi with 3.5ms. (coincidentally that is 142cc of fuel at 2000 RPMs – which should be good for about 280-350 HP at 2000 RPMs…..)

Lets talk about the IPR for a moment. Everyone talk about how important it is, and talks about taking it out and cleaning it, etc… but few talk about how it actually works. Think about it like this – it is basically an electric solenoid that is being fed a signal from the computer. This signal is a series of high and low voltages that dictate the strength the magnetic field contained within the solenoid. By varying the strength of this field the IPR is regulating the amount of oil that can bleed off from the system. A strong field is trying to hold as much oil in the system as possible; a weaker field is trying to bleed off more oil through the IPR to help maintain a pressure. So when comparing injectors, HPOPs, tuning, etc… that is why everyone talks about the duty cycle of the IPR – that duty cycle is basically how strong the IPR is. So in essence if you swap nothing else but pumps – and your IPR duty cycle drops under similar conditions – then your new pump has a higher volume output than your old pump –OR- something about the pump/setup has less of a pressure drop.

OK so far we have looked at a WOT scenario and looked how many different variables effect the pressure (volume) of oil available to the injectors at any given time, engine RPM, IPR Duty Cycle, Commanded PW, Commanded ICP, etc… but unless you’re a competition rig – how does this effect you? Lets take a look at what goes on when you are hooked to a trailer pulling a grade. To save a little time I am going to borrow some work from Charles done in Smack Talk – some things have been changed to protect the innocent and it has been cleaned up a bit, but none the less it is still his scenario:

Quote:
For an example of work, take a scenario of an PSD pulling a trailer climbing a 6% mountain grade for 6 miles with a loaded trailer behind it as would be the case pulling Mont Eagle grade in Tn.

There is a specific amount of work involved with that task.

Lets say the GCVW is 20,000lbs. Now if we forgo the complications of friction, wind resistance and all that for the moment, we can figure the primary force acting on this truck and trailer which happens to be gravity.

A 6% grade is a 2.7* angle. From this we can figure the component of gravity that is acting on the vehicle attempting to pull it down the slope.

We would have 20,000lbs straight into the earth and a component of 942lbs headed down the slope.

So the force involved here is the 942lbs, or 4190 N (Newtons).


The distance is 6 miles, or 9504 M (Meters).


Knowing this we can calculate the work required to move this vehicle to the top of Mont Eagle.

Since Work is Force x Distance, it's as simple as 4190 N x 9504 M = 39,821,760 NM (Newton Meters, units of work).

So that's your work. That's literally what must be done. Any engine can do it, the only question is how long will it take. That's where power comes in.

For instance....

Lets say you managed 45mph up this pass in this truck. Traveling 6 miles at 45mph would take you 8 minutes from bottom to top. Now we have our Time value. The important one...

8 minutes is 480 seconds.

We know that Power = Work / Time, so it's as simple as 39,821,760 NM / 480 s = 82,962 Watts of power required to do that task in that time.

What is Watt you might ask? It's a unit of power, just like kilowatts (1000 watts) or Horsepower, or Joules per second, so on and so forth.

So how many Horsepower is 82,962 Watts? Well it's 112 Horsepower.

Now lets say – I don’t want to go 45mph up that hill…. I want to do 70mph up that hill!

The only thing that changes is the amount of time it takes to climb the hill – only 5.1 minutes to reach the summit or 308 seconds. That boils it down to 129291 watts or 174hp.

Now you might want to know where I am headed with all of this and how it applies to what injectors, HPOPs, tuning, etc….

Lets examine the situations just discussed – 112hp at 45mph and 174hp at 70mph. Looking at some gear ratios – lets just say it’s a 6 speed truck to eliminate any of the argument for the TC slippage, etc… it can also show that things like the P1211 code can be as much of a driving style and tuning as it is an actual problem. The truck also has 33” tires and 3.73 gears.

First the 45mph scenario – in OD this can be done at about 1300 RPM, In 5th gear you will see it about 1725rpm, in 4th gear you can see it 2225rpm, and not practically done in 3rd gear by a “stockish” truck running a set of hybrids and a turbo towing a trailer. For arguments sake I’m going to assume 2.2hp per cc of fuel injected. So to make 112hp we will need to inject 51cc of fuel. At 500psi ICP that’s about 2.75ms, at 750psi that is about 1.75ms, at 1000psi that is about 1.5ms, at 1250psi that is 1.4ms, at 1500psi that is 1.3ms at 2000psi its 1.2ms, at 2500psi its 1.1ms, at 3000psi its about 1ms.

For the most part the goal is to inject fuel at the highest pressure possible to get the best atomization possible – but this is also a balance of being able to produce the pressure, as well as inject the fuel in an appropriate time window for a controlled burn. That is an entire thread all by itself – maybe some other day…..

So now I have all these data points of pressures and PWs that can inject the fuel I need to do the task – and a handful of RPMs where I can meet my speed goal. So now what…. Well those RPMs dictate the flowrate of the pump in a volume per time – those PW numbers dictate the rate that oil is required to use the associated ICP – Basically what that means is if the oil flow requirement for the injection event of a certain PW is not met by the pump – then you can’t maintain the pressure that is called for and BAM – the dreaded P1211…

Lets look at these data points – given some inefficiencies in the pump, max possible IPR duty cycle, etc…. at 1300 RPMs we can not inject fuel any faster than about 1.5ms and maintain 1250psi, at 1725rpms we should be able to manage in the 1.2ms with about 2000psi, and can do pretty much anything we would like to do in this scenario at the 2225rpm mark. Asking for any more than about 2000psi at 1750rpms is just going to result in popping a code – at 1300rpms don’t think about any more than 1250psi or expect a nice yellow light on your dash.

The 70mph scenario yields about 2025rpms in OD, 2650rpms in 5th gear, and is not practical in 4th gear. To make the 174hp we will need to inject 79cc of fuel. At 750psi that is roughly 2.5ms, at 1000psi its about 2.1ms, at 1250psi its about 1.9, at 1500psi its about 1.6ms, at 2000psi its about 1.5ms, at 2500psi that is 1.4ms, and at 3000psi that is about 1.25ms. Looking at these data points at 2025 we should be able to run about a 1.5ms PW at 1000psi, at 2650 rpms we can hit any of our targets.

Its important to note that for any of the above data we can extend the PW longer, lower the ICP demanded and inject the same amount of fuel required for the task with no risk of not being able to meet the commanded ICP. None of the above takes into account anything with your turbocharger, or any other variables of driving up and down the road – but it does go to show some of the requirements that the injectors can exert on a high pressure oil system. There are lots of variables and this does not hold perfectly true in every case due to some of these variables – I hinted here and there about some things that can make these numbers seem out of place.

That’s the quick and loose version of how the injector setup can place demands on the high pressure oil system. It will be a few days before I can take this to the next level and show the effects of different injectors and different pumps on this system that must work together – For arguments sake I will stick to only 238cc hybrids for now – I will just change tips around – or pumps around – not total injector capacity. The moral of the story will be the faster injectors demand more oil (because they can expel more fuel per time) and the larger the oil pump the lower in the rpm band you can hold pressure on a set of injectors. Additional food for thought – just because you can dump all your fuel at full ICP pressure just off idle, doesn’t make it a good idea….
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  #5  
Old 07-31-2012, 09:15 AM
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An old post talking about the effects of faster fuel injection:

Quote:
Originally Posted by HotRodTractor View Post
Standard theory disclaimer here guys. It is just physics and is the basic principles that I operate under. Its more along the lines of this is how I build my truck and if you disagree it don’t matter…. The following information and graphs show concepts and will put you into a ballpark, not guaranteed results. There is no garantee that the computer will even work at the extreme end of the RPM band, but I think it is good for a good ways North of where we are...

I’m going to try and explain why we have been talking about fast injectors and what that means, implies, and what we hope to achieve by advancing this technology. And trust me this is EXACTLY how the rest of the mechanical world keeps advancing and stepping up its game. For all out max power that will ALWAYS remain that way. But for everyone that would like to drive their truck everyday or keep up with the common rail crowd this applies to your truck!

First lets take a look at some 238cc Hybrid injectors with 80% tips. Here is a 3d graph that I generated from flow data collected on a typical set of these injectors:



You can tell that the fuel quantity maxes out as ICP and PW maximize. Nothing particularly spectacular about that. But I then took this data and overlapped that with the FDCS capabilities of the 7.3L PSD. Then I removed some of the high fueling down low on a WOT run and used that information on fuel quantities to generate HP and Torque curve capabilities. This doesn’t take into account any other limitations other than fuel, and can be shifted around by tweaking parameters. Not here to argue the numbers, just show the concepts that the graphs represent.



Looks pretty much exactly like a “typical” hybrid dyno graph except it goes to 6K RPMs right? I ran it out to 6K RPMs to help illustrate our current fueling capabilities and further my point. Notice that the graph peaks at about 2800 RPMs? Pretty familiar huh? By the time you pull enough torque out down low to make your motor live, you will never empty an off the shelf 238cc injector. You can add more power capabilities in down low by adding in more PW below this, but this also ups the torque curve which one of the reasons we all need all these fancy billet rods and junk…..

Compare those HP and TQ curves with many dyno graphs of a PSD with hybrids and you should find them pretty close in concept and shape. Probably similar peak numbers in some instances, a little low for others a little high for the rest.

Now here is the 3d flow graph of a “FAST” 455cc injector:



Yep. That’s a lot more fuel in the same period of time compared to the 238cc hybrids with 80% tips. There is way more going on there than just a tip change – but that is a subject that I won’t discuss in detail.

Now – Take this information and run it through the same process I ran the hybrid data through….

HP and TQ curve:



NOW I’m not here claiming any HP numbers, but this is what the data says. I limited the torque to 1200ft-lbs to show something that might be possible to make live. Note that even doing these limitations the peak of the HP line happens roughly 1000 RPMs higher. The limitations to peak HP are occurring because we passed the point where the max quantity of fuel can be injected. Faster injectors have helped move the curves farther up the RPM band, but they are not fast enough to move the peak any farther up. As the technology continues we will be able to move that peak even farther up the RPM band.

What about the guy that doesn’t want all that fuel, and just wants a good driving truck? What does this mean for you?

Lets take those fast fuel mods and run them on a “standard” 238cc hybrid.



It maxes out the fuel quantities for a much larger portion of the 3d graph simply because there is no more quantity to be had. Lets take that and look at what a theoretical HP and TQ curve:



NOW that’s what I am talking about. That would make one nasty, drivable, and fairly competitive truck in some classes. Torque was held to a level where a “stock” bottom end would live, but that says nothing of balancing, valve train, engine clearances to run RPM, etc…

Verification of data….

Take at look at Nate’s dyno sheet:



Now he is running the injectors that the 455cc flow graph was generated from. While on the dyno he was only using about 1.5-1.6 ms of PW throughout the run based on OBDII data. (Charlie – yes I know… need to verify with a scope… I agree, but it hasn’t happened yet)

Here is the theoretical chart based of off 1.6ms of PW using the flow data from the injectors:



Not perfect, but close enough to say that the data works for peak HP. If I were to massage the torque curve differently then I could get closer there too, but its not worth it for what I would like to show. The truck was not really tuned in and was having some wastegate issues that are now resoved. (I think anyway... Nate would have to confirm that.....)

Take it for what its worth. The data is showing that we are making progress. And I think we have made a lot in recent times, but there is a lot yet to go. I have no idea what happens to the HP/cc ratio does when nitrous is added…. I assume that moves the value up substantially.

Discuss.
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Old 07-31-2012, 09:17 AM
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A post about just some general injector issues associated with turning the wick up.

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Originally Posted by HotRodTractor View Post
In the end I don’t care if you agree with me or not – these are the basic underlying theories that make my truck run. None of these are real numbers of anything on my truck, and the example is somewhat extreme to show the issues of the systems, but not too extreme that it is unrealistic. At the rate that these competition trucks are being converted to Cummins or 7.3 p-pumped conversions there aren’t many of us that are up to the challenge left. Personally I am not a brand loyal kind of guy, I do it for the challenge, but eventually with everyone jumping ship, the challenge will probably get old. I hope that this thread in light of some of the more recent developments will get some guys thinking about the issues ahead of them if they want to pursue a similar path to making a 7.3 run with the competition. Also I would like to get people to start thinking about how a change in one part of the SYSTEM effects the rest of the system. This is nothing more than a thought invoking thread.

Lets suppose that I want to go out sled pulling with my 3.0 charger p-pumped Cummins buddies. The PSD is obviously the long shot in that competition so we want to look at it and tweak anything we can just to make it competitive. Those 5.9 p-pumped motors are spinning 6K RPMs so lets make the PSD do that.

Poof – I borrowed Lott’s wand and wizard hat and there is nothing stopping the PSD from spinning 6K RPMs from a controls standpoint. Program it, add a second IDM, whatever doesn’t matter.

There are 400cc injectors in the truck. We work some magic on them too so they can empty all their fuel in 48 degrees of crank shaft rotation at 6K RPMs, just like a p-pump is capable of. The injectors empty in 1.33 ms of actual injection, add in a token 0.5ms of injector delay and your at 1.8ms of called for PW.

To empty a 400cc hybrid inject in 48 degrees of crankshaft rotation at 6000 RPMs requires 5 times that volume in oil at BARE minimum. In keeping with the BARE minimum theme that’s 18.75cc/rev of the HPOP assuming its being driven by the factory gear. That is 23.8 GPM of engine oil just for the injection system. At 3200 psi that is 44.4HP just to drive the damn HPOP. In order to have 23.8 GPM of engine oil going through the injection system, we will need at least that PLUS what ever number we feel that we need to keep our bearings and piston cooling jets operational. Lets just call it 34 GPM as an arbitrary number. Raise your hand if you think there is a replacement LPOP that goes in the factory location that will output that kind of flow.

Lets take a look at 400cc B-codes for arguments sake. That is afterall the injector of choice by many performance enthusiasts. That take 6 times the amount of oil as fuel flow - 22.5 cc/rev of the pump to be exact. BARE minumum. At 6000 RPMs thats 28.5 gallons per minute of oil just to run the injectors, at BARE minimum. At 3200psi of HPO thats over 50HP just to drive the the damn HPO pump!

400cc injectors being emptied at 6K RPMs require over 150GPH of diesel fuel just to keep up. Nothing being returned to the tank.

That takes care of a broad overview of the fuel injection system – I avoided two key things the magic to make the injectors do what I am asking, and the magic need to control them. Lets take a look at the injectors a little bit closer – only as a broad overview –

There have been many threads talk about how to get the fuel out of the injectors, bigger tips, SHO mods, cut pistons, poppet lift, etc…. The oil needs to go in with the least amount of pressure drops possible, and go out quickly. The fuel needs to go in quickly, and go out with the least amount of pressure drops. Sounds nice and simple doesn’t it? I’m not going to go into ANY details about who is doing what, that is proprietary to each shop as far as I am concerned, but I will put one thought into eveyone’s mind, just for one little piece of this puzzle to be contemplated – Lets look at a poppet with stock lift – exactly like 99.9999% of people have. It opens and the oil flows past it. Well now its flowing enough oil at 3200PSI to empty a 400cc injector in 48 crank angle degrees at 6000 RPMs, and it’s a hybrid. What if I were to suggest that there is 1500psi pressure drop across that poppet seat? Your intensifier piston is only seeing 1700psi of that 3200psi that you put in….. pretty damn f’d up eh? The entire injector is full of issues like this. Its amazing these things work as well as they do for what we are asking of them. That pressure drop for a b-code is over 2100 psi………

I’m going to refrain from the controls hardware and programming issues, but be aware that there are plenty. I do not yet know enough to say any more than what is being said in the many threads about IDM/PCM programming, communications, and limitations.

There it is guys. Just think about all that junk for a while. When your done thinking about all that, think about how that is only a glossy overview of all this BS thats involved with making this junk run with the rest of the crowd. I'm going to the shop......
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Last edited by Hotrodtractor; 07-31-2012 at 09:34 AM.
  #7  
Old 07-31-2012, 09:25 AM
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Awesome post from Dave (golfer):

Quote:
Originally Posted by golfer View Post
Without getting tooooo explicit.

From a purely mechanical standpoint, what happens when the injector fires?

In this order:

Armature plate lifts (simultaneously lifting the poppet valve)

HPOil pressure begins, begins, begins, begins, begins, begins, begins to transfer its pressure through the poppet valve.

now...stop...freezeframe.

nothing internally has even begun to MOVE inside the injector...there has been no FLOW through any oil or fuel side components OR potential restrictions.

WHY?

The nozzle, or more specifically, the spring holding the nozzle needle SHUT (typically requiring @ 2750psi on stock injectors to begin to LIFT) is still closed...I mean we are talking tenths of ms here...but bear with me.

The nozzle needle will not begin to lift until (use your MATH here, as there is no flow, no restrictions to change the dynamically changing volumes, due to part movement, within the injector)..

on an hybrid, "5:1" injector, with a 2750 "pop" nozzle...there actually has to be at least 550psi (2750 divided by "5") of OIL pressure transferred through the poppet ..so the pressure begins to be transferred through the poppet ONTO the intensifier piston which will then transfer ITS' pressure "5:1" to the plunger...100, 200, 300psi, 400, 549psi(still...nothing has moved)

*crack* the nozzle needle now lifts exactly at 550psi HPOil psi (2750 fuel psi at the nozzle)

now sh!t starts moving...since fuel is FLOWING out of the nozzle.

the intensifier piston starts to stroke downward (simultaneously moving the plunger against the fuel)...creating MORE SPACE (more volume to be filled by HPOil) above the intensifier piston, so we have a pressure drop across the poppet valve...

On one side of the poppet valve...we have ALL THE OIL IN THE WORLD...oil rails FULL of "extreme ICP" :hehe:

on the OTHER side of the poppet valve...the side that is constantly/quickly increasing in volume (because the IP is "falling away") we have less pressure...this is not easily measured directly, but my previous post is 'proof'.

OK...so oil is trying, DYING to get through the poppet valve...trying to 'keep up' with the ever increasing space created by the void left behind as the IP moves down...more pressure drop....all the while, you have your "extreme ICP" just hanging the "F" out in your high dollar pumps, and within the oil rails in the heads.

starting to see what's happening?

now, put a BIG ASSSSSS nozzle on that injector...ya know...like the 200% EDM's that are available...hell, we'll make it "best case" scenario...and keep the VOP of that nozzle at factory levels...at 2750psi "pop".

now, all this happens again...now, with an even LARGER nozzle like we have now...all the internal parts are going to move STUUUUPPPPID fast...as that big ass nozzle offers no real restriction to flow...so we create an even LARGER pressure drop across the poppet...

(at the nozzle) injection pressure is horrible because the F'n oil can't "keep up" with the IP dropping faster than the oil can get in...

NOW, let's make it a B-code!!!! 40% larger oil side to fill...same oil restriction at the same ol poppet valve...

now...

I hope anyone & everyone here involved in this thread can agree...HPOil is THE key to making good power with the HEUI Power Stroke injectors. Doesn't matter if you have 100cc's or 1000cc's...if you don't have "good ICP" the truck is a turd...smokey...inefficient...

now, what happened when you put that twin HPOP on your truck? Bam!

Instant throttle response...much more crisp, much cleaner burn...much more efficient.

I could get into all kinds of crap about 'instant' HPOil pump output...and how THAT can affect oil 'flow' through the poppet...but hopefully my video illustrates that a 300cc B-code injector needs to move (6 x 300mm^3) 1800mm^3's of oil THROUGH the poppet in UNDER 2ms....every single injection event...every single injector...

a hybrid only has to move (5 x 300), and an A-code (7 x 300)...see a pattern here?

Volume of oil per time is the key.

know wonder we have so many quitters ...very, very few people understand the F'n HEUI injector...and none are as committed to it as us. Period.

I'll stop now, and clarify if needed.

but...hybrids use LESS HPOil per volume of fuel delivered than ANY type of injector out there...and the OIL is the key to making power with HEUI's...


always has been.
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Old 07-31-2012, 09:36 AM
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A post I made from a couple of days ago on here just so we can start putting everything together into one thread.

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Originally Posted by Hotrodtractor View Post
Since my name was brought up a couple of times in this thread - I'm going to make some comments that may not really answer the OP's questions - but its some info that I think people need to see and know about. Many people have asked me about the injectors that I have spent time and money on creating - I have no real desire to speak about them directly or specifically -but want to show some things about injection speed and control.

Here is the graphical representation of a standard set of 238cc hybrid injectors with an "80%" tip:



Now certain things can be done to those injectors to improve the injection speed - things like a larger tip, fuel side injector modifications, etc.... that is easy to do and the initial results show pretty substantial gains in flow rate across the board:



Now that's all well and good - we've got more fueling capabilities - but at the same time we have lost a bit of control resolution making them harder to tune for - you just can't dial down the tuning as quickly and easily in certain areas and the transition periods going from different ICP settings or PW times can be a little finicky - this is shown mostly by the sloping of the injection graph - its nice and steep from all angles and ramps up to some pretty significant fueling capabilities. The real trick is to continue with the modifications to the injector to improve upon that control resolution to make it better to drive, easier to tune, and overall more of a pleasure to own and enjoy on a daily basis with more power and RPM capability than what are current standard issue injectors:



Now before I get criticized - the first two graphs are actual data - I used actual data that I have to mimic the third graph for this example to make it a better visualization for everyone. This is the same volume and the same injector tip, and even the same "fast fuel" mods - but it has other things that have been tweaked to further improve the control. This is what makes a high flow rate injector more controllable and driver friendly - take note at how it has a much less steep fueling curve.

Now I brought up this information because myself and the vendors that I deal with for injection have been slowly working on improving the control-ability of the high flow rate injectors on our own time and our own dime. The injection rate that we have is well over 400cc of fuel in a very usable time window - the trick is controlling it effectively - I have no desire to give the OK to the vendors to begin shipping these injectors that are finicky to tune and control.

So if money was no object - well over 400ccs of fuel in a usable time window in a controllable package could be finalized and sold. We all recognize that its a short and dying list of people that even care any more about this - there is really no way that we can recoup the costs even at this point - that is why we are not rushing anything - its a losing battle on the money front and we are doing it for us - when things are ready - they would be available through the vendors that I work with.

Jason
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Old 07-31-2012, 10:49 AM
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littleredstroker littleredstroker is offline
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I may have missed it. There was a lot to read. What exactly is pulse width

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Old 07-31-2012, 11:31 AM
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Quote:
Originally Posted by littleredstroker View Post
I may have missed it. There was a lot to read. What exactly is pulse width

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PW is simply the DURATION of the electrical signal that goes to the injector solenoid...

looks like this:

http://swampsdiesel.com/IDM/Injector%20Waveforms.htm
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