DPF and Regeneration - Something to challenge you.

[ucpa111]

So, I have a couple questions and thoughts on the DPF and regeneration cycle. The way I understand the particulate side (not the DEF side - I understand it doses with urea and causes NOX to convert) is that the DPF collects soot and when the truck detects it's clogging, it injects fuel into the exhaust stroke to burn out the soot.

The injection of diesel on the exhaust stroke of the engine can cause dilution of oil, correct? And, on the 6.7, the diesel is injected during the exhaust stroke, correct?

So, my thought is this....what if you took the DPF and "gutted" it essentially. Kind of like leaving a catalytic converter in place, but hammering some holes though it to obtain flow? I realize this negates the intention of the DPF, but I assume it would also not trigger regeneration (and oil dilution and poorer fuel mileage). Has anyone looked at this, assuming my understanding is correct? I mean, in theory, the truck could look 100% stock (all sensors in place and operational - looks stock to the observer looking at the exhaust), but the inside of the DPF could be freer flowing. I believe pressure is what's triggering regens (pre DPF and post DPF differential pressure transducer)....or at least I know some vehicles use this b/c the company I work for makes differential pressure transducer assemblies for diesel vehicles.

Another way of looking at it....couldn't you take out the DPF and fabricate a flow through tube with the sensor ports in place and thus still have the truck computer stock and just never incur a regen?

To boil it down, assuming you could cut a hole through the inside of a DPF on the 6.7, would the truck still run properly (maybe even better with less backpressure) and just not regen and have better mileage (assuming all sensors in place and not harmed)?

Is anyone a mechanic on here who understands these trucks concerning this point?

Thanks in advance.

[camdenlake]

If i recall from some research the truck will eventually do a regen anyway. For the hours or key cycle count. Think its there for failsafe.


Josh

[jesilvas]

Interesting.
I know that if you completely do a DPF delete, it goes into limp mode.

You should try this :

[wberry85]

It will cause constant regen without a tuner I think. You are also drilling holes into a $2500 piece of equipment. I am not very technical to explain the ins and out but that is what I have learned through research on here and other diesel forums.

[jesilvas]

Originally Posted by wberry85

It will cause constant regen without a tuner I think. You are also drilling holes into a $2500 piece of equipment. I am not very technical to explain the ins and out but that is what I have learned through research on here and other diesel forums.

I know that with sensors undone it will do that.
But leaving sensors in place is the question.

Pre DPF sensor shows 50 PSI. Post DPF sensor shows 50PSI.
In a "perfect system," that's what pressure would be. I know pre will be higher than post due to the DPF being the design it is.
Once pre DPF is a pre programmed pressure above post DPF, then it regens, cause it thinks it's clogged.
So if the two sensors always stay within the "safe" zone, you'd think you could get away with it.

[ucpa111]

jesilvas....that's what I think too. With all sensors in place, but just "clearing a hole" for the exhaust, it would make sense that it wouldn't regen b/c it wouldn't detect a buildup.

I realize that taking sensors out or unplugging them without a tuner would cause a problem. It's just an interesting thought. If someone were to fabricate a DPF replacement with the sensor ports, but no DPF inside, I think it would work. Then, in theory, couldn't you obtain a mileage improvement with this relatively "simple/inexpensive" solution? I realize that if I spend $1500 on a tuner and deletes, I can obtain this...but want to know if you can do it for $200...and stock programming....

[jesilvas]

If the bungs for the sensors are standard bolt sizes, it'd be easy to just get some nuts and weld em onto a blank piece of pipe.

[TheBoss]

Iirc, the pre and post sensor always see a pressure differential and flow differential and if certain criteria isn't met then it'll throw the truck into limp mode. I highly doubt it's going to be as easy as drilling a hole through it to get around it. Could be wrong but I doubt it.

[ucpa111]

Yeah....that's what I wonder. I just am curious if anyone knows for certain. It makes sense that there is some differential, but I don't know if they are using the sensors to detect a value or a theshold. In the KEEP IT SIMPLE method (which Ford may or may not do)...it makes sense to simply look for a certain differential and then send the signal to the computer. I guess we really need someone who knows.

This may be an easy way to save some money and improve performance.

I guess one way to know is to make a sample pipe, install, and try. If it starts to limp, we know it didn't work. But, I sure would like to know from someone who knows. I bet the tuner companies know. Likely, their system fakes out the signal(always sends the computer a signal saying it's fine) or ignores it...

[wberry85]

Well I suppose only way one to find out...break out the hole saw ucpa!

I guess I subscribe to the theory that surely someone somewhere has tried this and if it were possible all of the us after better MPG could save $1000+ by just modifying our current DPF?