Still looking for the elusive...

[killerbee]

way to limit spoolup smoke on performance tuning, and maintain equivalence ratio. This has been discussed in other threads. Starting a new one (just for you tony) to see if there has been any progress.

The paradigm entrapped need not reply.

[bballer182]

The paradigm entrapped need not reply.

hmmm....


Well if thats me you are talking about i wont tell you about the CALC PID ive been working on that calculates EQ ratio for just this very situation. I've on a quest to remove excess boost where it's not needed and remove fuel where boost can't be produced efficiently.

It's taken days to get this thing sorted out. I was naive enough to base my instant MPG pid on straight MM3 values a long time ago and since then have realized that is grossly incorrect, however, it wasn't that far off. It is now based on the injector flow rate and the proportional relationship to the square of the current FRP.

I adapted the NEW calculation to readout EQ ratio and have not had a chance to get some logging done for this, as i have been playing with DSP too much.

But if this is not me you would be talking about i would be willing to talk to you privately about this, if you would like.:)

As for the software development of this EQ tuning...
Ross's brain has been consumed with the DSP stuff and is trying to make the LMM deadline before SEMA.

[GMC-2002-Dmax]

way to limit spoolup smoke on performance tuning, and maintain equivalence ratio. This has been discussed in other threads. Starting a new one (just for you tony) to see if there has been any progress.

The paradigm entrapped need not reply.

I admire your persistence, its called MAF Limiting.............:hihi:

Your goals are much different than mine, I understand that there is not a 100% fix for everything and I accept it, there are always tradeoffs and simple physics dictates that you always give a little to get a little.

Tony

[killerbee]

Yes MAF limiting. So far, elusive with Bosch.

There is rpm fuel limiting...seems to be limited in effectiveness and tradeoffs may be high.

[killerbee]

hmmm....


Well if thats me you are talking about i wont tell you about the CALC PID ive been working on that calculates EQ ratio for just this very situation.

We can have this discussion off-line if you like. Here is the one I have used before, not mine, IIRC fingers may have been involved, it is several years old. Credit where credit is due.

As you point out FRP is key to assessing actual dosing, and does vary with the square of pressure.

"({GM.MAINBPW}+{GM.PILOTBPW})*sqrt({GM.FRPACT})/({CALC.CYLAIR}*16115)"

If you have anything to share in this regard, feel free. PM is fine also.

[bballer182]

We can have this discussion off-line if you like. Here is the one I have used before, not mine, IIRC fingers may have been involved, it is several years old. Credit where credit is due.

As you point out FRP is key to assessing actual dosing, and does vary with the square of pressure.

"({GM.MAINBPW}+{GM.PILOTBPW})*sqrt({GM.FRPACT})/({CALC.CYLAIR}*16115)"

If you have anything to share in this regard, feel free. PM is fine also.

I'm having a heck of a time trying to get the EQ ratio figured out. I've used that equation too and currently have a version of it with the NEW calcs based on advertised injector flow rates. Question is; what does the "*16115" represent?

[killerbee]

a number of conversion constants. I have never set out to create one from scratch, however any one that uses mass of air, and mass of fuel, with some logic, is good enough for me. I don't look for perfection with this, just a useful comparator in logs.

Still, it is hardly useful, if void of any programming tool that allows you to balance air and fuel.

Or is there another way?

[bballer182]

a number of conversion constants. I have never set out to create one from scratch, however any one that uses mass of air, and mass of fuel, with some logic, is good enough for me. I don't look for perfection with this, just a useful comparator in logs.

Still, it is hardly useful, if void of any programming tool that allows you to balance air and fuel.

Or is there another way?

That equation converted to Bocsh pids created wild and non-logical values.

I'll PM you with the calcs i have come up with

[Racehemi]

I have used Fingers equation to help me tune my LLY for couple years now. I believe that he fudged the 16115 number until he could see a light haze coming out of the pipe at WOT. Because the LBZ injectors have a different flow rate you will need to tweak the 16115 number to suit the LBZ injectors. IMO, the easiest and by far the fastest means to accomplish this is to install a wide band oxygen sensor into the front pipe and start comparing meassured EQ to calculated values and tweak accordingly. Be sure to filter out the calc.cylair values once the MAF has been saturated or maxed out or your results will be skewed. Obviously you will need to substitute LBZ PIDs for the following LLY PIDs before you begin. Let me know if I can be of any assistance, I used this method on an LB7 with 40 over injectors with some success.

"({GM.MAINBPW}+{GM.PILOTBPW})*sqrt({GM.FRPACT} )/({CALC.CYLAIR}*16115)"




That equation converted to Bocsh pids created wild and non-logical values.

I'll PM you with the calcs i have come up with

[killerbee]

you will need to tweak the 16115 number to suit the LBZ injectors.

I agree. One vehicle specific constant. Should be easy to solve for a new one.

What did you see for eq when running highway unloaded, no boost? I seem to remember around 1.0??? Or was it 0.6?

[bballer182]

I agree. One vehicle specific constant. Should be easy to solve for a new one.

What did you see for eq when running highway unloaded, no boost? I seem to remember around 1.0??? Or was it 0.6?

I think i remember reading a while back (about a year ago) he had concluded that .6 was optimum for cruising (highest MPG) and .9 netted the highest HP. And i have been reading (not forms) that 1.0 is definitely way over stoich.

[killerbee]

That sounds very familiar. Concussions have handicapped me. :) Plus a little aged.

Let's start with this then,

({GM.MAIN1T_DMA}+{GM.PILOT1T_DMA})*sqrt({SAE.FRP_C })/({CALC.CYLAIR}*16115)

determine what this yields in a zero boost log, then solve for the variable to make the logged EQ good to 0.6.

Does that sound like a plan?

[bballer182]

That sounds very familiar. Concussions have handicapped me. :) Plus a little aged.

Let's start with this then,

({GM.MAIN1T_DMA}+{GM.PILOT1T_DMA})*sqrt({SAE.FRP_C })/({CALC.CYLAIR}*16115)

determine what this yields in a zero boost log, then solve for the variable to make the logged EQ good to 0.6.

Does that sound like a plan?

So you are saying that in a zero boost cruise that the truck will naturally cruise at .6? then solve to find the "16115" value?

[killerbee]

I think that is correct.

[killerbee]

So if you are running down the hiway (zero boost) and eq is logging, on avg, 124 (hypothetical), then the new PID constant becomes, (124/0.6) * 16115=3330400

[killerbee]

I backed the PID into old logs, it looks to be not too far off as written. .3-2.1 range on the (hypertech) log.

That 2.1 is on the wot section, exactly as predicted, during spoolup. NOW, what can I do about it?

side note: this log is the just the worst performance imagineable, some of these cookie cutter companies should just committ suicide.

edit: something was wrong with that truck, idle MAF was logging 2 lb/min

[killerbee]

So you are saying that in a zero boost cruise that the truck will naturally cruise at .6?

a little more memory coming back. As I recall, LLY cruise was maybe around 0.4-.5, even zero boost it was lean.

[killerbee]

I think i remember reading a while back (about a year ago) he had concluded that .6 was optimum for cruising (highest MPG) and .9 netted the highest HP. And i have been reading (not forms) that 1.0 is definitely way over stoich.

I seem to remember also , anecdotally, that 1.0-1.2 had the best spoolup characteristics, with minimal polution.

This was back in the day of pre-induction overhaul, so these numbers might be a bit less now.

More FWIW.

[bballer182]

Hmmm. Ok, well i'll have to play with it some and see what i can find out.

[bballer182]

I backed the PID into old logs, it looks to be not too far off as written. .3-2.1 range on the (hypertech) log.

That 2.1 is on the wot section, exactly as predicted, during spoolup. NOW, what can I do about it? pull some fuel in the areas you saw those ugly numbers and play with the timing a little.

side note: this log is the just the worst performance imagineable, some of these cookie cutter companies should just committ suicide.

edit: something was wrong with that truck, idle MAF was logging 2 lb/min


I agree! I had a BullyDog before EFI and owned the two at the same time so i pulled the BullyDog tunes with EFI and was shocked at the lack of "skill/craftmanship" (for the lack of a better term) in their tunes. I felt utterly sick knowing those tunes were being run in my truck...:bad::damnit1:

[killerbee]

You say pull fuel in those areas. There is maybe a dozen different ways to do this. Pressure, pulse, a number of torque limiting tables...

I am curious about any methodologies that may work better than others.

[Racehemi]

EQ of .5-.6 sounds about right for cruise, I was tuning WOT and did not really care that much about cruise conditions. An EQ 1.0 =s stoich and will yield a haze out of the pipe. How are you going check that you are in fact at 1.0 after playing with your calculations? I strongly suggest an LC-1 or a NGK WBO2 for reference.



I agree. One vehicle specific constant. Should be easy to solve for a new one.

What did you see for eq when running highway unloaded, no boost? I seem to remember around 1.0??? Or was it 0.6?

[killerbee]

I personally don't need it to be accurate to a nat. For me, it is one of many tools, and I use it for the quick visual of high departures from desired.

I am much more interested (in this thread) in coming up with good methodology for tuning out the smoke.

[bballer182]

You say pull fuel in those areas. There is maybe a dozen different ways to do this. Pressure, pulse, a number of torque limiting tables...

I am curious about any methodologies that may work better than others.

In my dsp5 tunes i have made sure that all 5 of my tunes have the "pedal to desired toque" (B1115 and B1116) the exact same trough out the 5 tunes, because that one tables can reek havoc on the TCM if one were to have a non-standard pedal to desired torque table. So that would usually not be an option for me. So that brings me down to TBIQ, pulse, and pressure. This is where it gets to be kind of preference area. I think i remember reading that you had built your tunes around a base pressure? so that ould bring us down to just TBIQ and pulse. Personally i think i would end up using the TBIQ just because I think it's a little easier to work with that table than the pulse table. On the other hand it might be more wise to adjust the pulse table because there are no compensation tables and adjust tables that deal in pulse time. they all seem to be in the TBIQ tables. So if you go straight to the source and play with the pulse table you might not even have to examine all of the adjusting and correcting tables???

[bballer182]

EQ of .5-.6 sounds about right for cruise, I was tuning WOT and did not really care that much about cruise conditions. An EQ 1.0 =s stoich and will yield a haze out of the pipe. How are you going check that you are in fact at 1.0 after playing with your calculations? I strongly suggest an LC-1 or a NGK WBO2 for reference.

I have read in a couple different sources that an EQ of 1.0 was not stoich and was a little over stoich. (not in forum talk mind you) Do you have any info that would lead us to believe 1.0 is stoich? Keep in mind that stoich is in a perfect world and is theoretical. so it may very well be stoich when talking about and LBZ???

[killerbee]

...so if I understand the pulse idea, that would require a timing considerations as well?

[bballer182]

Yes, good point. So i guess the difficultly level is the same...???

[killerbee]

Got a problem. ENGTRQREF is not validating for my LMM logs. I know it worked for LBZ logging.

I can log it, seems to be correct, but I have the red X.

[GMPX]

What about table B0795 for limiting fuel via MAF flow?
Though I think the missing piece of the puzzle with B0795 & B0796 is how that is then transformed in to either a torque limit or mm3 limiter.

[bballer182]

Got a problem. ENGTRQREF is not validating for my LMM logs. I know it worked for LBZ logging.

I can log it, seems to be correct, but I have the red X.

OOO, dunno about that, I would have thought it would have worked on the LMM. In BBL there are quite a few to choose from. try some of them out.

[bballer182]

What about table B0795 for limiting fuel via MAF flow?
Though I think the missing piece of the puzzle with B0795 & B0796 is how that is then transformed in to either a torque limit or mm3 limiter.

LMM stuff huh...

[bballer182]

Got a problem. ENGTRQREF is not validating for my LMM logs. I know it worked for LBZ logging.

I can log it, seems to be correct, but I have the red X.

Oh i guess i forgot to ask are you working with the LMM or the LBZ or both. I just figured LBZ.

[killerbee]

What about table B0795 for limiting fuel via MAF flow?
Though I think the missing piece of the puzzle with B0795 & B0796 is how that is then transformed in to either a torque limit or mm3 limiter.

where do I start with that? "lambda"? sounds scary.:cucumber:

I am working on LMM (today), but the fuel limiting challenge aspects applies to all bosch.

[Racehemi]

This may help

Fuel - Stoich AFR by weight
Gasoline 14.7:1
Diesel 14.6:1
Natural Gas 17.2:1
Propane 15.5:1
Ethanol 9.0:1
Methanol 6.4:1
Hydrogen 34.0:1
Nitromethane 1.7:1


Air fuel ratio can be expressed in different ways for different purposes. Many of the tables in the PCM are displayed as equivalence ratios. Equivalence ratio is the ratio of fuel to air where stoichiometry is defined as 1.00.

To convert EQ Ratio to AFR, use: AFR = {stoich}/EQ

To convert Lambda to AFR, use: AFR = Labmda/{stoich}

To convert AFR to EQ Ratio, use: EQ Ratio = {stoich}/AFR

To convert Lambda to EQ Ratio, use: EQ Ratio = 1/Lambda

To convert EQ Ratio to Lambda, use: Lambda = 1/EQ Ratio


At any rate I feel you will have more accurate results based on measured values vs some calculation that was not validated.


I have read in a couple different sources that an EQ of 1.0 was not stoich and was a little over stoich. (not in forum talk mind you) Do you have any info that would lead us to believe 1.0 is stoich? Keep in mind that stoich is in a perfect world and is theoretical. so it may very well be stoich when talking about and LBZ???

[killerbee]

Thanks for contributing Racehemi. :)

[bballer182]

x2:)

[killerbee]

What about table B0795 for limiting fuel via MAF flow?


is there an LBZ equivalent of this table?

[bballer182]

is there an LBZ equivalent of this table?

nope,.. Well there is but Ross said that is was in the OS's for the LBZ's but it had been "tuned out" (made non-functional) I asked him in another thread if it was possible to activate that table and release it to us. He said he would look into it after SEMA / DSP

[killerbee]

Damn SEMA.

[GMPX]

Try sitting on a plane for 14hrs to get there.

[bballer182]

Try sitting on a plane for 14hrs to get there.

Yeah i had 12 hour flight to Grand Cayman. I know what you mean.

[killerbee]

Try sitting on a plane for 14hrs to get there.

I've done that trip. But admittedly, I had more fun going supersonic. Wanted to see if it made any difference to the direction the toilet flushed (coriolis) while over the equator.

(yes, I'm dead serious!) :)

[killerbee]

nope,..

Were you able to use the eq ratio formula to derive a pid for B0795 evaluation?

or, I haven't bothered to look, maybe the lambda pid is already there.

[bballer182]

Were you able to use the eq ratio formula to derive a pid for B0795 evaluation?

or, I haven't bothered to look, maybe the lambda pid is already there.

More like i haven't got around to it yet. The only tuning i have done was track down a timing rattle while decelerating. Only happened randomly, not like one cylinder per rev, or anything consistent. Tracked it to the pilot during deceleration with no main. So i backed off the main timing even though there wasn't a main injection the pilot was basing it's timing off of what the main would be doing. Which also leads me to believe there is a table similar to B0758 in the LLY's, since it wasn't every cylinder doing it.

I do want to get that EQ stuff going though...:)

[killerbee]

disregard. I forgot you don't have the table I am talking about.

[bballer182]

disregard. I forgot you don't have the table I am talking about.

795 and 796?

[killerbee]

Yes

[vortecfcar]

B0795 works on the LMM, must first activate it using B079,4, and 7. The PID I was trying at the time did not work, but the fuel values do change based on B0795. I've used values around 1.2/1.5 with varying degrees of success. This was on a big injector truck though, so be advised.

Table is useless above 3200rpm, full fueling results past said RPM.

Nick

[boccheballs]

Wow reading these threads leads me to believe I might be over my head with EFI for a while! :confused:

[bballer182]

Wow reading these threads leads me to believe I might be over my head with EFI for a while! :confused:

it takes a while bro. it certainly doesn't come over night.

[duramaximizer]

It's like falling off a log backwards. All it takes is for you to get your feet wet.