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I know it's been beaten to death on this site but I'm going to ask one more time. What is the micron rating for the stock GM filter? If not already, is there going to be a 2micron (or close to) stock filter sometime in the future rumored? I guess the Nicktane is the way to go on primary.....that racor contraption looks like an expensive deal..why the pump? My plan would be to run a 10 micron primary and 2 secondary.
 

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While we are on the topic, I have an additional question. How is it that people are seeing better fuel economy after installing a Nicktane or other filter as the primary before the factory filter? I have seen that reported in several posts, but don't understand why that would happen unless the filter ultimately results in lower fuel pressure at the injector and so less fuel being used. Can't imagine the amount of pressure drop from another filter would do anything to fuel consumption, so I don't understand how it improves fuel economy?
 

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srode said:
How is it that people are seeing better fuel economy after installing a Nicktane or other filter as the primary before the factory filter?

Best answer I have ever heard to that question, may or may not be all bull, it that Bosh designs the injectors to spray a certain pattern with fuel filtered to its specs. Larger particles can disrupt the pattern which makes the engine less efficient. As already stated, don't know if this is true or not but know my truck's mileage has consistently picked up about 1/2 mpg after adding a Mega.


Jim
 

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I agree with JEBar, I dont quite know how it works either.


My assumption goes with his. The injector only passes X amount of fuel with each spray. With just the OEM, you get more contaminants with the fuel, resulting in a less even burn. With cleaner fuel, you get more fuel per shot(read higher BTU's) which offer a better combustion effect which I assume would also increase power demanding less fuel for the same task.


All I know it does seem to make a difference I saw better mileage with it all summer and now that winter has returned I'm still up almost 1mpg per gallon. Breakin may have something to do with that as well, but hey, better is better I'm not going to question it.
 

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srode said:
How is it that people are seeing better fuel economy after installing a ... filter...


....unless the filter ultimately results in lower fuel pressure at the injector and so less fuel being used...


Srode,
Jim’s explanation for better mileage seems to makes sense. I can say for sure that the mileage gain (I see it too) is NOT due to lower fuel pressure as my setup includes a pre-filter/lift pump and a JK MegaFilter with fuel pressure set to a nominal 0psi at the input to the OE pump. The OE system has a low-pressure pump that feeds the high-pressure pump. Rail/Injector fuel pressure is regulated after the input to the OE LP pump.
Edited by: jbplock
 

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Our Duramax fuel system is *very* sophisticated, especially in the combustion/injection process. The closer we can come to a "perfect" fuel to compliment the optimum Duramax spray and burn process, significant efficiencies are the result.
As I had mentioned previously something as outlandish as passing fuel over a rare earth metal which (supposedly) aligns molecules can provide measurable efficiency increases. So if something as outlandish as molecular alignment/strings and mirrors can actually affect fuel mileage, our filtration is removing real burn inhibiting components. The particulates disrupt the computer generated optimal burn and depending on the amount and type of contaminant removed, significant burn efficiency improvements can be realized.
With older less efficient low pressure mechanical fuel injector systems ultra fine filtration would have had little measurable affect.
Welcome to state of the art diesel fuel system design where computer generated perfection meets real world dirty fuel!
George Edited by: Georgecls
 

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All the dialog about fuel mileage is great, but you guys totally hijacked Top Gas's thread in that he asked about the micron capabilities of the stock filter.
 

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Soo, in response to Topgas Original question::
The OEM fuel filter test results show it to be 45% to 65% efficient in removing the 5 to 10 micron particle size. The 5 to 10 micron particle range size is *the* culprit causing accelerated pump and injector wear.
The secondary filtration units (Baldwin, Cat, etc.) have been testing in the 98% to 99% efficiency level for the 5 to 10 micron size contaminant. Which is the cleanliness level we need to be to achieve for fuel system life maximization.

George Morrison
 

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Plus the emulsifying additive
(too complete the story of fuel system life maximization)
 

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The stock filter is rated at 2 micron.

On the topic of emulsifying additives... A question to George - If water is emulsified in fuel , how much water in fuel will begin to cause injector wear? How much water in fuel will be destructive to the injectors?

Related to your fuel filter tests, I assume that the measurements that you made are 1 pass measures. Isn't there a return line back to the tank? So, the fuel can take multiple passes through the filter before hitting the injector? If this is so, what do single pass numbers really mean?

If the above is right, will refueling at one-half tank mark improve the overall cleanliness of the fuel hitting the injectors when the tank is full?


thanks,
jeff
 

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I wouldn't want to take much credit for "bypassing" the injectors and getting multiple filtering passes, Jeff. The poorly filtered fuel has gone through both stages of the injection pump including the incredibly close tolerances required to produce the high fuel rail pressure (23,000 psi) where it could even have succeeded in gouging up some NEW contaminants from the pump internals - then the contaminated fuel at full pressure is at least partially circulated through the injector operating chamber to provide hydraulic pressure to cycle the injector when the solenoid opens the pilot valve AND to provide cooling flow for the injector where it could also PRODUCE more contaminants in the moving parts of the upper injector -THEN it is depressurized and routed back to the fuel tank. The bypass is by no means a nice passive process offering extra filtering as you seem to believe.
 

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Jeff, regarding your question of how much water can safetely be emulsified. From my experience and testing, for diesel fuel (bio diesel is quite another matter, however) 100 ppm of water is about the limit. Remember, we really aren't attempting to emulsifying all the potential worst case water. The emulfication capabililties of Primrose and FPPF is limited to reasonable, normal levels of water. Water that in most cases is already loosely emulsified in the fuel. We are chemically 'locking it up' to make absolutely certain it doesn't get a chance to fall out of loose suspension and create free water which IS, certainly damaging both in loss of lubricity but also corrosion, implosion, etc..
So, we are essentially surrounding normal levels of water with a lubricating covering which prevents the water from looking like water; moreover it looks like H2O surrounded by a nice oiled surface, preventing the above and allowing the H20 molecule to pass though the system as tho it was not water.
Now, for a water 'slug'. The emulsifiers in fuel additives cannot begin to address that level of water and it will be up to our water separator/alerter to do its job. A slug will remain in the system as free water, posing all the horribles of potential pump/injector damage, corrosion, bacterial growth, etc. etc.
Emulsifying fuel additization provides us with a constant protection for normal levels of water which are still very much capable of creating all of the above problems if not controlled on a continuous basis.
George
 

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Thanks! I saw a GM Tech post on another forum that fuel made multiple passes through the filter. Didn't know all the critical components it flowed through on the way!!!

Do you know how much fuel is recirculated back versus delivered to cylinder?

thanks,
jeff
 
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