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vortecfcar
August 26th, 2009, 01:28 AM
I've been doing some mixture limiting tests using B0795. The table works okay once activated, but doesn't limit fueling past 3200RPM, which results in a sort of N20 hit at said RPM.

If there's a way to scale the table out to 4800 with just one more column, it would be much appreciated here.

See the sudden jump in fueling at 3200... this is with the whole table set to one value. Also notice that the Lamba PID is not reading anything useful (it also never moves from .625). I don't know if there are any more useful PID's for this application, but I'm willing to try them if there are.

http://i105.photobucket.com/albums/m201/vortecfcar/mixture_issue.jpg

Any insight would be appreciated.

Nick

GMPX
August 26th, 2009, 10:50 PM
Hi Nick, I have been holding off allowing the scaling of tables in the Bosch. We did do it for that one table in the LB7/LLY's that controlled a lot of the RPM lookups, but the Bosch does it for each and every table almost, currently in V7 it's a mess to configure the axis to be changeable, I'd like to avoid it for V7, V8 has it implemented better.
If you want to Email me a file I can change it outside of EFILive if you want to do some testing.

Cheers,
Ross

killerbee
March 26th, 2010, 05:42 AM
x2

also interested in a PID that is useful for tracking this. I would like to know if the lambda value is based on a calculation, or a sensor value. If calculation, what fuel parameters are used? mm3, or pulse/pressure combination? We might just have to come up with a pid, perhaps the inverse of eq ratio that has been used.

Racehemi
March 26th, 2010, 04:48 PM
x2

also interested in a PID that is useful for tracking this. I would like to know if the lambda value is based on a calculation, or a sensor value. If calculation, what fuel parameters are used? mm3, or pulse/pressure combination? We might just have to come up with a pid, perhaps the inverse of eq ratio that has been used.


Sensor value? I don't recall any of our trucks having a wide band O2 sensor installed from the factory.

You should be able to twist the parms in Fingers EQ Ratio PID to work in the newer trucks however, your new calculations need to be calibrated with a WBO2 or you are guessing at best.

bballer182
March 27th, 2010, 03:22 PM
Sensor value? I don't recall any of our trucks having a wide band O2 sensor installed from the factory.

You should be able to twist the parms in Fingers EQ Ratio PID to work in the newer trucks however, your new calculations need to be calibrated with a WBO2 or you are guessing at best.


I have done that, and i'm pretty sure Michael has done this as well and we both have concluded that the fudge number in Fingers' equation is pretty damn close if not correct for the LBZ/LMM. But you are right and Wideband would be awesome to have backup that number.

Racehemi
March 29th, 2010, 03:18 PM
If you have not installed a WBO2 sensor you have no idea how accurate the formula is. You can pick up a WBO2 for under $200 and know for sure.

killerbee
March 29th, 2010, 04:07 PM
I don't know why it would be important to establish accuracy in the formula. It is only useful as a reference for making predictable changes to lambda, presumably. The table isn't based on any chemistry reading.

The Eq Ratio PID can be tweaked based on empirical table matching. But doing that would be easier if the "lambda" value had a definition that didn't imply that it is a sensor reading itself. Answering the question, what is lambda expressed as a calculation? (since there is no sensor). The fact that lambda must be based on some definition of pulse and pressure (assumption), or mm3 (another assumption), renders an actual sensor reading irrelevant, because a sensor reading represents a physical observation. The table is not a physical reality (presumably), it is a calculated representation of something that is likely non-deal in nature.

Add to this, there is no table that can adjust fuel, based on a non-stock sensor, so adding one would be nice-to-know only, for adjusting emissions. It would be informative, but un-useable as a predictor for a lambda value that is based on other known fuel parameters. (even mm3 is a reference parameter, not representative of an actual volume, therefore misleading) Perhaps I am wrong or missing a good point. Sorry for rambling, just figure this is an important perspective.

Racehemi
March 30th, 2010, 03:43 PM
Not sure what you are saying Micheal but after data logging with a WBO2 for a few years now I stand by my statement. That calculation means nothing unless it is accurate. And, if you can twist it enough to be accurate at some point, (WOT for instance) it will not remain accurate across the entire operating range of the engine.

killerbee
March 31st, 2010, 02:24 AM
Sounds interesting. Have you developed any PIDs with the O2 information you have gathered? Or drawn any wholesale conclusions?

bballer182
March 31st, 2010, 11:09 AM
Not sure what you are saying Micheal but after data logging with a WBO2 for a few years now I stand by my statement. That calculation means nothing unless it is accurate. And, if you can twist it enough to be accurate at some point, (WOT for instance) it will not remain accurate across the entire operating range of the engine.


Sounds interesting. Have you developed any PIDs with the O2 information you have gathered? Or drawn any wholesale conclusions?

Interesting indeed. Wondering also if you have developed any calc.pids with WO2 correction built in.

Racehemi
April 1st, 2010, 02:42 PM
Sounds interesting. Have you developed any PIDs with the O2 information you have gathered? Or drawn any wholesale conclusions?


PID's? I serially attach my LM-1 to my V2 and use the PID supplied by Ross and Paul. I stated my conclusions above as well as in the past however, an expert or two normally shows up and proceeds to tell anyone that will listen that "AFR on diesel doesn't matter, just throw fuel at it". That's usually when I bow out.

bballer182
April 1st, 2010, 03:04 PM
PID's? I serially attach my LM-1 to my V2 and use the PID supplied by Ross and Paul. I stated my conclusions above as well as in the past however, an expert or two normally shows up and proceeds to tell anyone that will listen that "AFR on diesel doesn't matter, just throw fuel at it". That's usually when I bow out.

So i take it you never bothered to compare the calc.pid to what the LM-1 has to say, obviously because u have the LM-1?

killerbee
April 1st, 2010, 03:15 PM
PID's? I serially attach my LM-1 to my V2 and use the PID supplied by Ross and Paul. I stated my conclusions above as well as in the past however, an expert or two normally shows up and proceeds to tell anyone that will listen that "AFR on diesel doesn't matter, just throw fuel at it". That's usually when I bow out.

That's in the past. I can't afford to be narrow minded. :)

Racehemi
April 2nd, 2010, 04:26 AM
So i take it you never bothered to compare the calc.pid to what the LM-1 has to say, obviously because u have the LM-1?

I did compare my LM-1 readings to the results of Finger's calc.pid and found the logged values to be close under most WOT conditions. Once verified, I twisted the formula around to calculate my pulse width based on a desired EQ of 1 at WOT. That said, keep this in mind.

1) I was only concerned about WOT fueling.
2) My truck is a MY 04.5 LLY, if you have another version of the Dmax and/or larger injectors the formula will require an adjustment to maintain accuracy. IMO, verification of accuracy is best performed with the aid of a WBO2 sensor.



The WBO2 accomplished two things (at least) for me.

1) It served as my eyes to see how the truck was fueling when I was not present. In other words I no longer rely on the driver or spectators to tell me how much the truck was smoking, I review my logs and know exactly.

2) Allows me to dial in a consistent fuel curve though out a particular engines operating range.

bballer182
April 2nd, 2010, 11:13 AM
gotcha. so how is/was the LM-1 holding up? Good? bad? would you choose it again?