it's scary what can be found in an ECM

WOW....and your a "tuner". You unplug the FCA you know why it goes to max pressure? BECAUSE IT GOES TO MAX VOLUME!!!!

Open up the "Fuel pressure regulator Base duty cycle" and get back to me when you get the concept of volume.
 
Brandon I know what you're getting at and its the main reason I've trashed most of the stock cummins tables and started from scatch. I don't understand how some get the results they do by simply smoothing and modifying the stock tables.
 
I am well aware of what volume is. Volume is simply a given space, it's a finite area that you have to work with. What happens when you cram more things into that space, you get PRESSURE!

The ECM measures PRESSURE, not VOLUME.

The Base Duty Cycle is nothing more than a limit for the FCA. 99% of the time the ACTUAL duty cycle of the FCA is MUCH lower than the commanded.

It's no different than the main duration table. The value in a given cell is simply the LIMIT of how many uS that injector can fire at that point on the map.

How about this....YOU get back to ME when you can show where VOLUME is measured in the fuel system. The FCA is valve, not a sensor, all it does is what it's told to do....open or close and for how long.

Unplug the FCA and it goes wide open. Everything goes to the rail. That' show it gets VOLUME....Pressure x Time = a given VOLUME of fuel.

So yeah.....WOW!
 
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And then what have you done....you've increased the size of the orifice in the valve.

It's no different than increasing the size or number of holes in the injector nozzles.

Increase the orifice size and maintain the same pressure and what do you get?....more volume.

Volume is dictated by Time and Pressure.

Pour 5 gals of water at 1 gal per second for 3 seconds. What do you get? A volume of 3 gals.

Pour 5 gals of water at 3 gals per second for 1 second. What do you get? A volume of 3 gals.

You can change the volume either with PRESSURE or DURATION.
 
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Cummin-a-long said:
I am well aware of what volume is. Volume is simply a given space, it's a finite area that you have to work with. What happens when you cram more things into that space, you get PRESSURE!

The ECM measures PRESSURE, not VOLUME.

The Base Duty Cycle is nothing more than a limit for the FCA. 99% of the time the ACTUAL duty cycle of the FCA is MUCH lower than the commanded.

It's no different than the main duration table. The value in a given cell is simply the LIMIT of how many uS that injector can fire at that point on the map.

How about this....YOU get back to ME when you can show where VOLUME is measured in the fuel system. The FCA is valve, not a sensor, all it does is what it's told to do....open or close and for how long.

Unplug the FCA and it goes wide open. Everything goes to the rail. That' show it gets VOLUME....Pressure x Time = a given VOLUME of fuel.

So yeah.....WOW!
Click to expand...


AGAIN WRONG. The Base duty cycle is NOT a limit for the FCA!!!:nail:

IT IS the best estimation of the VOLUME of fuel required to hit the target pressure. Because again all we have is a VOLUME control valve......:nail:

The PID works DIRECTLY from this table, the closer this table matches the actual volume needed to maintain pressure, the less hard the PID needs to work.

That idea of volume sinking in a bit yet??
 
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I tell ya what.....you roll with that.

I'm done arguing about it.

You look at it any way you like, it makes no difference to me.

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Yeah, educate me.....CompD style. Okay.
 
Ain't anything hard about it.

You haven't backed up a SINGLE thing you spouted yet.

Again, SHOW ME THIS VOLUME CONTROL AND WHERE IT's MEASURED AT.

You know what's a KNOWN variable? Pressure, it's measured.

You know what else is? Time, it's fixed and commanded.

You know what changes in relation to time and pressure, both of which are KNOWN by the ECM....Friggin' Volume.

Show me the measuring device in the rail that calculates volume when a larger rail is used...that's right, there isn't one. The pressure is measured.

When I want a given VOLUME of fuel, I dicate it with pressure and time. Increased Duty Cycle is only needed if the commanded cycle isn't able to maintain PRESSURE.

WOW!
 
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well, I can say I'm happy to be running a tune from Rich. You're not given credit where it's due.... this is one point and there are several variables involves. In my logging with his tunes I've hit every value set without going into the red and beyond. If any of those values are changes, the truck changes with them.
 
I've backed up everything, show me a pressure regulating valve???

Already showed you the Base pressure regulator duty table and its relation to volume, and when you understand that your tunes will be that much better.

"Volume when a larger rail is used"......your just not getting it.....
 
There are as well actual pressure control valves, used more in European vehicles (In place of our mechanical pressure relief) . In this case the pressure PID works directly on it, and the FCA or volume control valve has a fixed table to work from. This table is the best estimation of the required volume to get close to what is required to make the pressure.
 
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Joesixpack said:
There are as well actual pressure control valves, used more in European vehicles (In place of our mechanical pressure relief) . In this case the pressure PID works directly on it, and the FCA or volume control valve has a fixed table to work from. This table is the best estimation of the required volume to get close to what is required to make the pressure.
Click to expand...

So, if this is going over his head like you say, what is being missed or left on the table in the tune ? Remember too, the tunes being talked about aren't Rich's. In his tunes, those tables have been adjusted and they work.
 
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His tunes could be great, I'll take your word for it. Calling the Pressure regulator duty table a limiter or not understanding its relation to fuel volume a tuner does not make.

However.....do applaud him for putting it out there, don't see one single other tuner out there doing the same.
 
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And, in that, again you are wrong.

You seem to think that I don't understand exactly what the FCA is. Its a valve, nothing more, nothing less.

Duty cycle is nothing more than the time that valve is allowed to remain open to meet the fuel demand.

Only reason to increase duty cycle on the FCA is to meet demand for rail pressure. THAT is what is measured. MEASURED, NOT METERED, which is what the FCA does.

So, like I said, we're both seeing the same thing, you just seem to think that duty cycle is an estimation of volume, when its not. Is it allowing a greater VOLUME of fuel to flow with increased duty cycle? Yes, thats a given. If the valve is open longer, you get a greater volume of fuel through it.

The ONLY reason to increase that duty cycle is if your not able to maintain pressure. That's it. If your logs are showing pressure is being maintained, then what you're going to see is commanded duty cycle greater than actual. If the commanded and actual are the same, you're likely seeing rail pressure drop off and THAT is when you increase that duty cycle.

The base duty cycle is just that, the BASE table. All its doing is telling the FCA how much to open. If the duty cycle is too low, you don't maintain pressure.

So, exactly what don't I understand.
 
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Cummin-a-long said:
And, in that, again you are wrong.

You seem to think that I don't understand exactly what the FCA is. Its a valve, nothing more, nothing less.

Duty cycle is nothing more than the time that valve is allowed to remain open to meet the fuel demand.

Only reason to increase duty cycle on the FCA is to meet demand for rail pressure. THAT is what is measured. MEASURED, NOT METERED, which is what the FCA does.

So, like I said, we're both seeing the same thing, you just seem to think that duty cycle is an estimation of volume, when its not. Is it allowing a greater VOLUME of fuel to flow with increased duty cycle? Yes, thats a given. If the valve is open longer, you get a greater volume of fuel through it.

The ONLY reason to increase that duty cycle is if your not able to maintain pressure. That's it. If your logs are showing pressure is being maintained, then what you're going to see is commanded duty cycle greater than actual. If the commanded and actual are the same, you're likely seeing rail pressure drop off and THAT is when you increase that duty cycle.

The base duty cycle is just that, the BASE table. All its doing is telling the FCA how much to open. If the duty cycle is too low, you don't maintain pressure.

So, exactly what don't I understand.
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The base duty cycle is ABSOLUTELY the best estimation of volume flow PERIOD. Bosch and others call it "Estimated duty cycle" in reference to fuel volume....:nail:

The base table if it were to be set perfectly would perfectly match the volume of fuel required to maintain pressure at a specific mm3...(oh yes again volume fuel).

NOW in the real world you can never perfectly match that, so that why we have a PID to track pressure and make corrections to VOLUME FLOW to maintain pressure.

TO DO THIS, the PID directly uses the values in the base table as a reference and to more quickly and precisely make adjustments.

WHEN you are working the pressure regulator base table you absolutely are working with volume whether you know it or not.

Compd....educating the nOOb's the hard way since.......LOL Hey thats what needs to be up top...LOL
 
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