Lambda questions

Three questions for today:
What Lambda do you guys find makes the best power at full load? I was using .800 to .810 above 5k to be safe, but now I'm experimenting with leaner across the board with a max of .830, and it's better. It's crisper and pulls a little harder. I do have ~45% Ethanol in it, which no doubt buys me a leaner mix, but I don't know how much it buys. I also haven't tried leaning it on gas so I'm curious if people have tried, and what were the results, and of course at what boost? The oem Lambda on mine is very lean with a richest cell of .891, but it can't hit that cell so it's likely never richer than .920, which seems crazy to me. Makes me wonder how much leaner I can go?

How about Lambda at idle/cruise? Has anyone tried leaner than the oem 1.00? I've left mine at 1.00 so far, but per the O2 sensors, it averages more like .98 or richer. Desired & Command read 1.00 the whole time, and the O2's are all over the place, but avg is rich. Seems to me setting it to 1.02 would balance that out. Plus, why does it need to actually be 1.00 anyway, excluding emissions. I'm sure it'll run fine leaner than 1.00, so I was curious is anyone has leaned it, maybe even pushed it until it was unhappy.


The tough question: What is "Delta Lambda Factor"? I asked before and rec'd zero replies, so this time I'll throw in my theories:
At first I thought it was some command factor for 2nd fuel, meaning if the Delta cell was .8 and 2nd fuel is called on, then your actual command was 80% 2nd fuel and 20% Target. If so, why have a Delta, just make the 2nd fuel what it needs to be. Assuming there is common sense in its creation, it has to be something else, or more to it, but what?
The note at the bottom in HP says "Delta Lambda Factor dependent on ignition efficiency". It can't mean spark power so it must mean retard, and since retard = heat it must add fuel when retarded. Makes sense... Retarded from the Base Spark tables or the Optimum MBT table? I'd assume the MBT but mine is always very retarded from that.
Full spark advance exhaust temps are probably a known value that require xx fuel, but spark retard is a variable, which needs this additional table? Makes sense, but if so, I still don't understand how the Delta table works. What would that example .8 do? Is it a % of 2nd fuel as described above, or maybe it has nothing to do with 2nd fuel. Maybe it's an additional add on top of Target or 2nd fuel? Add xx extra fuel when spark is retarded, regardless of what else is happening? If so, how much spark triggers it, and more importantly, how much fuel? What does the example .8 do? Under light load the cells are 0, and full load the cells are 1.0, so I assume 0 means none and 1 means 100%, of whatever it's adding. Assuming my guess is even close...

.82 to .85
As to E85 the thing about Lambda is it does not matter what fuel you use. E85 isn't buying or selling.
.85 Lambda on gas = 12.50 AFR
.85 Lambda on E85 = 8.30 AFR

Yes, but Ethanol cools better and there's more octane, so less is needed. At least for me because no way I could lean it with pump gas. Even at .800 it would complain until I retarded the timing.
With the Eth I added 4.5deg spark compared to gas, so that's more cooling.
How much all that's worth I don't know. I guess I'll just have to lean it until it complains, or I lose power.
I have ~48% Ethanol in it now so 1.00 is ~11.80 AF. .850 would be 10 AF. And of course my mpg dropped to match, which is another reason I was thinking of leaning it. Plus I'm getting more soot on the back of the car than I ever, why I don't know but the timing is matching the Ethanol, as is the % of Eth I'm using. More reason to force it leaner I rekon.

How rich or lean depends on the fuel type, cylinder heat, egt, knock, boost etc.. so many factors
Ethanol blend or any other fuel will always shoot for 1.00 Lambda at idle so easier is to go by fuel trims to check if mixture is lean or rich then you will get the magic number.
Even if you go leaner with E% dont forget cylinder heat and EGT's as they build up over high rpm's and boost. In general if boost is above 14 psi richer mixture would be safe ex. 0.80-0.82


Delta Lambda Correction acts as how much you want component protection I would say to get faster changing the Lambda for example:
0.5 = less
1.0 = more

2nd Fuel is a map on the ecu that I suppose it was supposed to be used if the car had ethanol sensor (I wouldn't pay much attention to it) as there is a map called Ethanol Enrichment which is not there on hptuners and it acts as Power Enrichment for normal Fuel type. That map acts as the 2nd Fuel in my opinion no use for them as the ecu cant detect ethanol with no ethanol sensor.

To sum up just get the car the lambda it likes but with safe measures + good power .

I set my Target Lambda idle/cruise to 1.02 and it didn't work. Command was still 1.00 and O2's at idle/cruise still ~.980 or richer. So I set 2nd Fuel to 1.02 as well, and still nothing, but no surprise there. The only other place to set is Cat Heating, which did work, but only for 30 seconds or so after cold start and never again.
So I guess some other map or minimum setting we can't see, is blocking me.
Hmmm, maybe Power Enrichment will override it. That'll be more tricky...

outlaw:
Mine switches to the 2nd fuel map anytime I lean on it, so it's my main fuel tuning tool, but I also have to dial in Target.
Here's the problem; I can leave Target oem, and it works great, but too lean. At 4760rpm it's .930 and maxes at only .891, so ping/retard city until 2nd fuel kicks in, which takes a couple seconds. So I made Target richer to combat that, but it's not as rich as 2nd. It's just barely rich enough to not ping in that couple sec before 2nd kicks in.
If I make Target match my richer 2nd fuel, so there is no delay in enrichment, I lose power during that transition period, which makes it soggy and boost takes longer to get since it's soggy.
So it's a delicate balance of fuel and time to just barely avoid ping, but no more. The result is a much crisper throttle and more power.

I'm still at a max of .830 on my 2nd fuel and so far so good. Rekon I'll go to .840 soon. Per my brain, I think I should be able to go to .850, assuming my 45-50% Ethanol content. Just like the leaner Target helps, a leaner 2nd fuel helps too. My current .830 nets a noticeable power gain over .800, and again quicker Tbo spool. Between the two fuel maps it makes a big difference in the time delay between flooring it and pushing me back in the seat. Huge difference.

As for Delta, you're saying it's an urgency, or a timer, to switch from Target and richen fuel. That makes more sense than my theory about being a % of Target vs 2nd. I guess I'll have to experiment by using drastically different #'s to see what it does.
The part about 2nd fuel being ignored and some Ethanol map used makes no sense to me, for my car that is. I wonder if maybe M157 motors are wired that way? Just a guess because I noticed M157 has a rich Target but 2nd fuel is way too lean, so I can't imagine that motor using 2nd. Mine, for sure, uses 2nd fuel. In oem form my Target and 2nd maps are identical. Weird... Like they weren't even trying.

Quote:

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Originally Posted by chevota

I set my Target Lambda idle/cruise to 1.02 and it didn't work. Command was still 1.00 and O2's at idle/cruise still ~.980 or richer. So I set 2nd Fuel to 1.02 as well, and still nothing, but no surprise there. The only other place to set is Cat Heating, which did work, but only for 30 seconds or so after cold start and never again.
So I guess some other map or minimum setting we can't see, is blocking me.
Hmmm, maybe Power Enrichment will override it. That'll be more tricky...

outlaw:
Mine switches to the 2nd fuel map anytime I lean on it, so it's my main fuel tuning tool, but I also have to dial in Target.
Here's the problem; I can leave Target oem, and it works great, but too lean. At 4760rpm it's .930 and maxes at only .891, so ping/retard city until 2nd fuel kicks in, which takes a couple seconds. So I made Target richer to combat that, but it's not as rich as 2nd. It's just barely rich enough to not ping in that couple sec before 2nd kicks in.
If I make Target match my richer 2nd fuel, so there is no delay in enrichment, I lose power during that transition period, which makes it soggy and boost takes longer to get since it's soggy.
So it's a delicate balance of fuel and time to just barely avoid ping, but no more. The result is a much crisper throttle and more power.

I'm still at a max of .830 on my 2nd fuel and so far so good. Rekon I'll go to .840 soon. Per my brain, I think I should be able to go to .850, assuming my 45-50% Ethanol content. Just like the leaner Target helps, a leaner 2nd fuel helps too. My current .830 nets a noticeable power gain over .800, and again quicker Tbo spool. Between the two fuel maps it makes a big difference in the time delay between flooring it and pushing me back in the seat. Huge difference.

As for Delta, you're saying it's an urgency, or a timer, to switch from Target and richen fuel. That makes more sense than my theory about being a % of Target vs 2nd. I guess I'll have to experiment by using drastically different #'s to see what it does.
The part about 2nd fuel being ignored and some Ethanol map used makes no sense to me, for my car that is. I wonder if maybe M157 motors are wired that way? Just a guess because I noticed M157 has a rich Target but 2nd fuel is way too lean, so I can't imagine that motor using 2nd. Mine, for sure, uses 2nd fuel. In oem form my Target and 2nd maps are identical. Weird... Like they weren't even trying.

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Does your car use 2nd Fuel Map when you have Ethanol mix only or all the time ?

Try setting the idle area in Power Enrichment cells to 1.02 and see if it will hold that as an override.
Also to set your target there is a trick sometimes works if you set all your Target Maps as stock and just change your PE Map to what you want on WOT cells.

What Peak Boost are you running and what happens if you richen the mixture less than 0.81 while you are on Ethanol mix?

I will set the scaling on Power Enrichment from 80, 90, 100% load to 60, 70, 100 and just set 60 to 1.02. Hope it works...
Not only would I like it not be .980, but I'd like to push it to see how lean it can go. Seems to me direct injection could allow a lot leaner mix than other fuel systems, but it's gotta cooperate first.

2nd fuel works with gas or my Eth mix, no change at all.

Boost varies between 22 and 12 depending on rpm. 22 up to ~4k, then drops steadily to 12-13 at 6k. I know you like to draw the line ~17 but I can't help myself.
.830 is what I'm at now, with 47% Ethanol. Setting to .800 or .810 simply makes less power. It may also be why I have a lot more soot on the back of my car, which I noticed increased as the % Ethanol increased. I've been adding more of late so it's more obvious. Now that I'm .830 it "appears" it has less soot than last week, but it's just a subjective opinion over a short time. It's not really much soot, but it's a white car so it's obvious. Whatever the story, there's certainly a lot more soot than when I ran straight gas, which basically produced a normal amount of soot.

I've never ran less than .800 with any Ethanol %, but I did go as far as .780 on gas, which I only did for a bit because it was pointless. Gas I used .800 or as lean as .810. With Ethanol and my .830 my spark is also 4.5 deg more advanced than gas. I should say my map is +4.5, it rarely follows the map though. Point being it's not exactly apples to apples, but close enough imho.

Thanks outlaw, your input is always appreciated

Quote:

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Originally Posted by chevota

I will set the scaling on Power Enrichment from 80, 90, 100% load to 60, 70, 100 and just set 60 to 1.02. Hope it works...
Not only would I like it not be .980, but I'd like to push it to see how lean it can go. Seems to me direct injection could allow a lot leaner mix than other fuel systems, but it's gotta cooperate first.

2nd fuel works with gas or my Eth mix, no change at all.

Boost varies between 22 and 12 depending on rpm. 22 up to ~4k, then drops steadily to 12-13 at 6k. I know you like to draw the line ~17 but I can't help myself.
.830 is what I'm at now, with 47% Ethanol. Setting to .800 or .810 simply makes less power. It may also be why I have a lot more soot on the back of my car, which I noticed increased as the % Ethanol increased. I've been adding more of late so it's more obvious. Now that I'm .830 it "appears" it has less soot than last week, but it's just a subjective opinion over a short time. It's not really much soot, but it's a white car so it's obvious. Whatever the story, there's certainly a lot more soot than when I ran straight gas, which basically produced a normal amount of soot.

I've never ran less than .800 with any Ethanol %, but I did go as far as .780 on gas, which I only did for a bit because it was pointless. Gas I used .800 or as lean as .810. With Ethanol and my .830 my spark is also 4.5 deg more advanced than gas. I should say my map is +4.5, it rarely follows the map though. Point being it's not exactly apples to apples, but close enough imho.

Thanks outlaw, your input is always appreciated

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Sure if its safe and you like the 22 more than 17 with right mods on car, then push it why not !!

You are welcome any time

The Power Enrichment idea didn't work, zero change :(

I was thinking of adjusting the O2 sensor bais, which I assume will lean it out, but how would I know? It would still read the same and I'd be wondering if I have it right or not. Of course I'll adjust it anyway but it would be nice have a clue what I'm doing.
Per the values, in the pix, what would I adjust the .630 at idle to be ~2% leaner? I doubt it's simply .630 x .98. I'd imagine it takes a lot more than that?

Attachment 133430

Quote:

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Originally Posted by chevota

The Power Enrichment idea didn't work, zero change :(

I was thinking of adjusting the O2 sensor bais, which I assume will lean it out, but how would I know? It would still read the same and I'd be wondering if I have it right or not. Of course I'll adjust it anyway but it would be nice have a clue what I'm doing.
Per the values, in the pix, what would I adjust the .630 at idle to be ~2% leaner? I doubt it's simply .630 x .98. I'd imagine it takes a lot more than that?

Attachment 133430

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Why do you want to go leaner

Because it spends all it's time ~.980, or richer, all the while commanded to 1.00. Why it can't adjust I don't know, but it's buggin me.
If I could command 1.02 then it should net 1.00, in theory. If I can go leaner, why not? Like when it goes into cat heating mode it can go 1.06 which nets me 1.035 to .1.040 according to the O2's, and it runs fine. So why dump .980 or richer down the pipe when I can do 1.04?

My latest thought is setting the "Desired Lambda After Start" injection count timer to 65535. I always wondered if that was pulses in one cyl, or total pulses. Seems like the former would make more sense but if not specified I'd have to assume the latter. Guess I'll find out, assuming it works.

Setting the timer to 65535 was a fail. Inj PW was ~.95 after start vs the normal .42

ME9.7: I had positive results with using Homogeneous Adder to offset the Injector Flow Rate per banks. Maybe try using a negative value to see if it produces the result your looking for... but it may just need more time with dialing in the Inj PW Multiplier if dealing with different injectors as well.

Spent about 3 hours today making change after change, idle is still ~.980...
I did discover that the tune I made that caused me to be super rich this am, now works fine. Go figure... I was trying to see what triggered it, but couldn't repeat it. Unless maybe it's only a cold start thing, but why would it be? Guess I'll find out tomorrow am. Maybe it made cold start enrichment get stuck? I dunno...

Manny, I don't know what a "Homogeneous Adder" is. Maybe I don't have that?
The Inj PW Mult won't do anything because that's sort of a baseline adjuster for fuel qty, or I suppose an open loop fuel map. The closed loop system, imo, references that but does what it wants regardless. I can make that chart drastically different and it does nothing to my Lambda. I've had it ~15% lean at idle for a while now, for a different reason, and no change to Lambda. So basically it's the closed loop Lambda I'm trying to adjust. Trying to make the O2's read 1.00 when fuel is being commanded to 1.00, and it just won't cooperate. Not really a big deal, but it's buggin me, and it's buggin me why it won't cooperate. I understand it can move and easily dip to .980, but then it should also spend as much time >1.00 to make the avg 1.00. Instead the swing is usually ~.995 to .950. It rarely hits or breaks 1.00, and usually when it does it also swings down low to make up for it, even <.900 sometimes. But overall the avg is ~.980, maybe .970 depending on how it feels.

Che: are you using OEM injectors? What are you using to measure lambda? My Innovate DLG-1 (using Bosch LSU 4.9 sensors) does read slightly leaner than the OEM upstream O2 sensors. So you could be exactly where you want to be….

Bone stock except K&N filters

Weird, it didnt show your whole post earlier, just the first sentance. I'm reading the oem sensors per the ecu via HP. So even if off it's what the ecu sees and should adjust to 1.00.

You need to idle richer on E blend its not like gasoline 1 lambda = 14.7

Why would it need to be richer? Plus, it's richer all the time, not just idle.