[decipha]

It has occured to me that there are many folks on this forum that are 'attempting' to tune and don't know the first step to tuning

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YOU CAN NOT ADJUST FUEL IN ANY WAY SHAPE OR FORM UNTIL YOU KNOW WHAT YOUR LAMBSES ARE GOING TO BE
with no multiplier's your LAMBSE will be what your demanding in your fuel table

you adjust your fueling to make your wideband MATCH your lambse

again

you adjust your fueling to make your wideband MATCH your lambse

once more

you adjust your fueling to make your wideband MATCH your lambse

THIS IS STEP 1 TO TUNING!!!!

you adjust your fueling to make your wideband MATCH your lambse

You do not change the maf curve to get the wideband to spit out the afr you want, you adjust the maf curve or injector values to get the wideband to spit out the afr the ecu is telling it to (LAMBSE)

the LAMBSE is the AFR the ecu is DEMANDING, if your lambse is 17 at wot and your wideband reads 14.5 at WOT then you are RICH and you need to pull some fuel out

likewise, if your LAMBSE at WOT is 8 and your afr is 12.5, you are LEAN and need to add fuel

this is called dialing in fuel, YOUR FUEL IS NOT DIALED IN UNTIL the wideband matches lambse

when this happens your fuel trims KAMs will be very near 1 at all conditions

once more

you adjust your fueling to make your wideband MATCH your lambse

[oneredstang]

more posts like this ftw

[Scaffy]

Ok, as someone whose never taken this approach before, do you adjust this under WOT only, or under all load conditions? Any more info would be greatly appreciated. If, at WOT, lambse is 17 and your wideband is reading 14, you say you need to pull fuel? So you pull fuel and you're now running 17afr? Do you do this across the whole maf curve, then use your multipliers to get your fuel right for WOT?

[xd41efisc]

Take open loop on an A9L without the fn1360 hack an no fuel multipliers in play for example.
Whatever is in the base fuel table will be your lambse.
E.G: At 80% Load with an ECT of 180 you will be looking at a lambse of 12.58.
If your wideband reads 11.58, you are to rich at this load point.
If you have a MAF voltage of 4.0 volts at 80% load, you go to that voltage point in the MAF transfer and reduce that kg/hr until you get 12.58 (or very close to it). You do this for all voltage points on the MAF transfer.
This is where EA (or the MAF auto tune in BE) makes life easy.
You can also change injector slopes to get the lambse to match on the wideband. (there are 2 schools of thought on this so use search to find more info)

ONCE you have your Lambse matching your wideband then your MAF/Injectors are dialed in.
NOW if you want to change your fueling you go to the fuel table and put in the AFR you want to acheive, in the relevant load/temp points.

As stated you DO NOT use the MAF transfer to get the fueling you want, you use the Fuel tables after your MAF/Injectors are dialed in.

[cgrey8]

Ok, as someone whose never taken this approach before, do you adjust this under WOT only, or under all load conditions? Any more info would be greatly appreciated. If, at WOT, lambse is 17 and your wideband is reading 14, you say you need to pull fuel? So you pull fuel and you're now running 17afr? Do you do this across the whole maf curve, then use your multipliers to get your fuel right for WOT?

There are 2 problems in this case.

The 1st problem is that the WB is indicating the mix is rich relative to the LAMBSE. So fuel needs to be pulled to get them to match. This is either a problem with the MAF curve or Injector parameters. If you are relatively confident in your Injector parameters, then try fixing this issue with the MAF curve.

The 2nd problem is the EEC is commanding 17:1 for LAMBSE at WOT which is stupid because that's too lean of an AFR (assuming gasoline) for WOT conditions. This is a fuel command problem somewhere in the tune. Somewhere, there are dumb values in the open loop fuel table/WOT function/fuel multiplers or there's some other problem that's preventing the EEC from recognizing the WOT condition and thus its staying in Closed Loop. Regardless, this problem is not a MAF curve fix like the 1st problem is.

[cgrey8]

...As stated you DO NOT use the MAF transfer to get the fueling you want, you use the Fuel tables after your MAF/Injectors are dialed in.

The only exception I have to this is an odd and evidently rare issue where fueling at low loads rolls all over the place based on whether the vehicle is sitting still or rolling. I've fought this issue since I got my V8 installed and I suspect the problem is a physical one with the way the MAF is installed. The problem manifested itself in lean conditions that caused driveability issues immediately after tip-in because the mix would be too rich when I'd approach a stop, so Closed Loop would pull fuel (raise LAMBSEs to leaner values). However as soon as I put load on the engine, the LAMBSEs Closed Loop had worked up to were way too lean. So the engine would stumble lean. Eventually Closed Loop would correct for this, but not before it caused hesitation. The annoying part is if I let the truck sit and idle vs rolling to a stop with the trans in neutral, the LAMBSEs would settle to a different LAMBSE value. So for the same RPM/Load/MAF flow values, I had different LAMBSE values necessary to meet stoic depending on the driving condition. That wasn't something I could tune for. I combated this issue with multiple hacks to the tune. The easiest and most significant hack was to simply make idle conditions lean in the tune. Being lean at idle when the engine isn't loaded is far better than being lean on tip-in. So I made idle lean. Closed Loop now responds by dropping LAMBSEs to richen the mix. Now when I tip-in, LAMBSEs are worked down, not up. So tip-ins are always a tad rich, not lean. Back when I had adaptive learning turned ON, this required that I disallow learning at idle and near-idle RPM/Loads so the EEC didn't learn away this intended adjustment. This alone fixed probably 80% of this issue. To further improve responsiveness, I monkeyed around in the HEGO (Closed Loop) controls to speed up Closed Loop responsiveness to both rich and lean conditions. Now my Closed Loop action is far more responsive than it was with stock values and works MUCH better. Even if I didn't have this issue, I think Closed Loop works better the way I have it setup.

All that being said, I realize "tuning around" mechanical problems is not generally recommended, but I didn't care. I took responsibility for whatever the results and I'm pretty happy with what I came up with. I've been running the truck like it is now for YEARS without any complaints or notable issues. But what this hack does is force a condition where LAMBSEs do not parallel actual WB feedback. So there are exceptions to rules. But exceptions are just that. They shouldn't be the norm or an excuse to not do the norm. They should only be considered as alternative strategies to fix problems with the normal recommended ways of tuning are giving no joy.

Although I believe my improvements to Closed Loop would work well on any vehicle NOT using long tube headers, I still wouldn't recommend people make these adjustments unless they are just looking to tinker OR they they've found that Closed Loop in its stock form is just too sluggish to respond.

[NotchAbove]

All great info here.

As has been said above, you adjust the fueling....does anyone wish to expand on this ?

[decipha]

for all conditions, the lambse is the afr the ecu is demanding


multipliers multiply lambse, THEY CAN NOT DIAL IN FUEL since the gap between lambse and the wideband will still be off by the same percentage

just for clarification, the 17:1 at WOT was my example to show you that the wideband reading means nothing if you don't know the lambse, no one in their right mind would demand 17:1 at WOT, 13:1 is more like it, to further that, most engines running at 17:1 at max engine effeciency aren't usually too happy and usually sputter breakup pop misfire etc..


even with known values fuel is seldom dialed in, 99% of the time its lean on the big end, take a stock supercharged lightning for example, they demand 12:1 at WOT and they only get 14:1, why i bring up the lightnings, because i find that just incredible and since they come stock with the 90mm meter thats many folks use which BTW has the maf curve dialed in perfect.



we all know or have heard of the decipha method of dialing in fuel, to each their own

[Scaffy]

Cool, cool. It all makes sense now. I do realize the 17:1 figure was just an example, but see now that it shouldn't actually be commanding that, unless someone's gone and inputted it into the fuel table. This thread's been mighty helpful, thanks fellas!

[275DragRadial]

Great article Dechipa.....sometimes we all need to get back to basics. I am guilty of over-complicating everything!

[EDS50]

Well I'm gonna throw my hat in the ring and call BS on some of this.

1. Witrh the known injector settings available out there for motorsport injectors, Why on earth would you go messing with the injector settings????

2. Dont any of you realize that when a mass air flow meter is flowed on the flow bench and calibrated it is done so with the FACTORY maf curve and injector settings for said application? And forget about even considering they are not calibrating it to exacting tolerances, they think within 10% is close enough and they figure adaptive learning will compensate for the rest....HAHA... With that being said, most if not all maf companies calibrate their meters to 19# injectors and a stock 55mm maf on 89-93 fox body applications for example. Pro-M/flow who ever they are now, provide flow sheets to input for those of us with tuning capabilities but not even those flow sheets are completely accurat since they are not utilizing the same air intake inlet track that you are physically using on your application. There is a wide variety of air inlet track and filter combinations and meter placement configurations to consider. Now, you can purchase pro-flow and granatelli maf meters that are calibrated to the injector you are using but is still tricking the computer. Those of you out there that build maf curves by free revving the motor to certain rpm values and averaging the kg/hr values and just interpolating values in between to me are just plain silly to do so because those average kg/hr values will drastically change under load and that is the reason why your are butchering your fuel injector settings. When I build a maf curve when a known curve is not available it is always on the dyno or on the street where the car is under load and aspirating realistic air characteristics with the vehicle moving. Idle is a different animal due to various cam combinations hence the reason for proper fuel injector/cam timing values that no one ever mentions. If you have to manipulate your known fuel injector settings that much to make your afr match your lambse or vice versa, then you maf curve is not as accurate as you may think for obvious reasons.

3. C&L meters are the absolute worst to dial in since they utilize the stock 55mm electronics on a fox body applicationin their housing and a interchangable color coded sample tube for whichever injector your using. All that is assuming you are still using the factory 19# injector and settings and factory maf curve. Then hope adaptive learning figures out the rest. What a shitty way to do things as there is too much trickery going on there to trust. My personal experience with these meters has provided me with a wealth of knowledge of what to do and what not to do in the tuning department which even made Lee Bender, owner of C&L scratch his head. With tuning capabilities you cant just call Lee or his staff and say I have so and so vehicle and combination and I need a maf curve from your flow bench to input in my tune. It wont happen. I went this route back when I had 24#'s. I input the motorsport injector settings for the injectors that I had and the flowbench curve he sent me and the car wouldnt even run. He swore to me up and down that there was something mechanically wrong with my car and that it wasnt the meter or sample tube or electronics. So, I decided to do some experimenting and found that you can not define the injector settings and flowbench maf curve he provides in the tune because it will be roughly 20% richer than it is supposed to be hence the reason why the car wouldnt run or idle. So I left the motorsport injector settings in the tune and started with the stock maf curve and worked on the maf curve in forced o/l. The car immediately responded and once I built my own maf curve based off the stock maf the car ran like a champ without ever touching the injector settings and setting all the multipliers to 1. The afr is spot on to what I command in the base o/l table all the way up to wot. Idle I dont pay attention to the afr (16:1) because of the cam and combination I have. Hell I can even lug the car without any bucking in 5th gear 35 mph 1100 rpm and shes smooth as can be. I would never expect my lambse and afr to match 100% since the ecm is using slow narrowband o2's to report to the computer and the afr uses a wideband o2 sensor which is more accurate, has a much wider range of operation and responds a lot faster then slow ass narrowbands. Decipha, wasnt it you who said to me at one time that you dont trust narrowband sensors under 13.0 lambse because they are just not accurate enough? So why on earth would you want to match your afr to an unreliable lambse reading at wot? If narrowbands were so wonderful how come tuners including you and I dont use them on the dyno to tune with?

4. I guess the moral of this story is that there is no 1 way to achieve the results you are looking for since there are so many different approaches to achieve the results you are looking for. There really is no right or wrong way or one definitive way like some claim or preach to be. You have to find out what works for you and your combination best.

5. This is not a personal attack on the o/p or any one elses oppinions, I just dislike when people open a thread and tell you how something is done and thats the only way to do it because I will call BS everytime. I do things my way and the o/p does them his way, Neither is right or wrong but it does show that their is more than one way to skin a cat. Those that wanna throw their hat in the ring and add their .02 are more than welcome too.

[Scaffy]

So EDS50, do you still spend time matching your AFRs with lambse, or you don't take this approach at all?

I've wondered about MAFs and different intake tracts. A while back, I got hold of a pod filter set up for nothing, which included a carbon fibre shroud that went in where the airbox sat, keeping the hot air out. Only problem with it was that the adaptor plate and pod's internal diameter were 2.5", when the airbox was 3". I spent a while setting it all up at a friend's workshop and on the drive home I noticed it was running extremely rich in open loop. With the airbox setup, my AFRs at WOT were 12.8 across the board with very little fluctuation. With this new set up, they were sitting at 10.8. Needless to say, I swapped it back when I got home.

If you get that much difference with half an inch, I dare say 5mm difference would make enough of a difference to need to make some decent changes. I would have thought those changes would need to be made in the maf transfer, as that's effectively the only thing that has been affected.

[EDS50]

Keep in mind with my tune on my vehicles I disable adaptives and force o/l. User the injectors settings to those provided by Ford racing and don't touch em. I set the base o/l fuel table to what i want to command and adjust the maf curve to match what i am commanding and it works like a charm for me. This way I don't have to deal with closed loop or adaptives getting in the way.

[EDS50]

As far as the air intake track configurations, any piping length or diameter change, or bend in front of the meter or air filter arrangement will change the air sampling rate of any meter so why would anyone adjust the fuel injector parameters to compensate for air sampling? When maf meters are calibrated its on a flow bench which is stationary and not under load actually drawaing air or aspirating air through the unit. If you have a known curve to input into the ecm thats a fantastic starting point but is not the be all end all answer. The maf curve still needs to be fine tuned. Even changing injector values does effect lambse and afr values no matter what you are commanding. Again, when you order a maf meter from any company they are assuming you do not have tuning capabilities and will calibrate it to the ecm that is "supposed" to be in the car which in the 5.0 fox body world is all 19# injectors with the exception of the 93 cobra x3z (24#) which would need to be specified at the time of ordering. If you define the actual injector settings (say 24#) on an a9l ecm and define the actual flowbench numbers (if they are provided) by the maf meter manufacturer you will be upwards of 20% over rich in your tune. Defining both values would be the ideal way to go about things as thats the way ford did it but when it comes to these maf meters that are calibrated to trick the ecm into thinking something is there thats not thats when the problems arise. In my experience with a "calibrated" maf meter you should define the injector settings as advertised by the manufacturing company (Ford Motorsport as an example) since injector values will not change unless they are flow matched or the fuel pressure is changed (which those specs are also provided by Ford Motorsport) and start with the factory maf curve and fine tune from there. OR define the actual flow bench valueas into the maf curve and start with the factory 19# injetor settings and fine tune the fueling from there but you cant define both. (I guess theoretically you can define both but you will be making too many other adjustments in base fuel tables and what not to compensate). Does it make sense to you to define the flowbench maf curve provided with the meter in the tune and tune based on hi and lo slopes and not have the slopes near what they are supposed to be? Of course not but I guess its 6 one way 1/2 a dozen the other way. I find it easiest to define the injector settings as advertised, set all fuel multipliers to 1, define the afr you want commanded in the base o/l table and forget about the fueling and just tune the maf curve accordingly to acheive the results you are looking for. Thats just me I guess. Also keep in mind adjusting slopes will adjust a broad range of driving conditions that just dont make sense to do. The lo slope is more critical than the high slope since it covers idle, and cruising conditions so you might fix your fueling during cruise conditions by adjusting the lo slope but what happens at idle? You gonna change the lo slope again? Think about it......I'm all talked out for now....LOL...

[tremec77]

Keep in mind with my tune on my vehicles I disable adaptives and force o/l.

Are you leaving it this way after the tune is correct or are you turning CL and adaptive back on?

[EDS50]

Keep in mind with my tune on my vehicles I disable adaptives and force o/l.

Are you leaving it this way after the tune is correct or are you turning CL and adaptive back on?

I leave o/l forced in my cars but for a customers car once everything lines up in o/l i will re-enable c/l and adaptive learning. I choose not to deal with adaptive learning around the changes I make.

[85GT]

So, hypothetical question. Numbers are just out of the air:

You're tuning at say 200kg/hr on the maf curve. I little rich so you drop it down to 180. That would the the approach and now your afr matches you lambse.

But what happens if that 200kg/hr is at 6500 rpm vice, 2000 rpm? At 6500, your pw may be so small, you'd be on the low slope and pw vs batt voltage can be a big contributor, where as at 2000 you are deep into the high slope with a large pulsewidth...

How does that get accounted for. I can see if WOT is you're only goal...

[bender460]

So, hypothetical question. Numbers are just out of the air:

You're tuning at say 200kg/hr on the maf curve. I little rich so you drop it down to 180. That would the the approach and now your afr matches you lambse.

But what happens if that 200kg/hr is at 6500 rpm vice, 2000 rpm? At 6500, your pw may be so small, you'd be on the low slope and pw vs batt voltage can be a big contributor, where as at 2000 you are deep into the high slope with a large pulsewidth...

How does that get accounted for. I can see if WOT is you're only goal...

It's not 200Kg/Hr any more it is now 180.. I'm confused... If pulse width isn't changed (assuming same lambse) why would the slope change from low to high? Is RPM playing a role in the break point?

[snowboarda42]

How does everyone compare their LAMBSE to their WBo2? Just manually scroll down the list?
And do you compare LAMBSE1 or LAMBSE2? Do they need to be dead on?

[NotchAbove]

How does everyone compare their LAMBSE to their WBo2? Just manually scroll down the list?
And do you compare LAMBSE1 or LAMBSE2?

With the tune I run both LAMBASE 1 and 2 are the same #, so I then move over the WB02 column next to it, and setup a formula to calculate the difference, % wise.

Make sure you save the file in excel verse CSV.This serves to preserve the original log.

[85GT]

So, hypothetical question. Numbers are just out of the air:

You're tuning at say 200kg/hr on the maf curve. I little rich so you drop it down to 180. That would the the approach and now your afr matches you lambse.

But what happens if that 200kg/hr is at 6500 rpm vice, 2000 rpm? At 6500, your pw may be so small, you'd be on the low slope and pw vs batt voltage can be a big contributor, where as at 2000 you are deep into the high slope with a large pulsewidth...

How does that get accounted for. I can see if WOT is you're only goal...

It's not 200Kg/Hr any more it is now 180.. I'm confused... If pulse width isn't changed (assuming same lambse) why would the slope change from low to high? Is RPM playing a role in the break point?

Pulse width will change, it has to.

Pulse width occur once every time the injector fires, once every two revolutions of the engine.

So, let say you are commanding 10:1 at both rpms. You need 18kg of fuel to support the 180kg of air. At 6500, you get to fire the injectors 3250 times a minute to get that much fuel. At 2000, you still want to deliver the same fuel, and you can only now fire them 1000 times a minute. You now need to fire each time roughly for about 3 times as long (the pulse width), no?

So maybe 2ms at 6500 vs 6ms at 2000. That could put you on different slopes, as an example.

[snowboarda42]

How does everyone compare their LAMBSE to their WBo2? Just manually scroll down the list?
And do you compare LAMBSE1 or LAMBSE2?

With the tune I run both LAMBASE 1 and 2 are the same #, so I then move over the WB02 column next to it, and setup a formula to calculate the difference, % wise.

Make sure you save the file in excel verse CSV.This serves to preserve the original log.

Good idea! What do you do if there's a difference in your LAMBSE1 & LAMBSE2? Or how did you get yours equal?

[EDS50]

So, hypothetical question. Numbers are just out of the air:

You're tuning at say 200kg/hr on the maf curve. I little rich so you drop it down to 180. That would the the approach and now your afr matches you lambse.

But what happens if that 200kg/hr is at 6500 rpm vice, 2000 rpm? At 6500, your pw may be so small, you'd be on the low slope and pw vs batt voltage can be a big contributor, where as at 2000 you are deep into the high slope with a large pulsewidth...

How does that get accounted for. I can see if WOT is you're only goal...

Yes, if you raise the kg/hr value it will make that point richer where lowering the value will make it leaner. However remember my approach is a little different since I tune in o/l and my lambses are locked onto what I am commanding in the base o/l fuel table. I match my afr to what I am commanding fuel wise by building my own curve that has better resolution than any generic ford or aftermarket flowbench curve. I create more resolution down bottom and mid range and less up top without having to worry about voltage stability. Also remember that you are never going to get lambses and afr to exactly match, you will be :headbang: to do so. Why will it never match you ask? Because narrowband sensors rely on x amount of hego switches and background cycles to report an event. By the time the event happens and shows on the BE display for lambse that event is old news and is constantly being updated but not exactly real world data. Its a delayed display of actual events if you will. The wideband afr is much much faster but still isnt displaying exact moment data. For example, when I had idle issues with rpm dropping under dsired rpm intermittently. When the event actually happened there was a delay in the afr gauge display swinging from stoich to 12.0 afr and then shooting up to 17.0 afr as I stepped on the clutch. It is only a 1 sec delay but a delay none the less. So basically I will always remember Deciphas words: "you are not tuning to be exact, just get it close enough and adaptives should bring the rest in line." Even when I tune in o/l and say im targeting 14.08 as stoich, does it really matter if the wideband gauge is bouncing between 13.8 and 14.2 while I'm cruising. I think thats close enough where if I enabled adaptives everything would come right into play as Decipha says.

As far as 200 kg/hr at 6500 rpm, you will never see that but I do get your point. This is where load and VE come into play. Thats also where your pulswidth adders and fuel multipliers come into play to compensate.

[EDS50]

How does everyone compare their LAMBSE to their WBo2? Just manually scroll down the list?
And do you compare LAMBSE1 or LAMBSE2?

With the tune I run both LAMBASE 1 and 2 are the same #, so I then move over the WB02 column next to it, and setup a formula to calculate the difference, % wise.

Make sure you save the file in excel verse CSV.This serves to preserve the original log.

Good idea! What do you do if there's a difference in your LAMBSE1 & LAMBSE2? Or how did you get yours equal?

If there is a difference between lambse 1 and 2 then one side or 1 bank of the engine is richer or leaner than the other. Usual contributing facotr is a bad or faulty or lazy o2 sensor or could be an injector hanging open or a vacuum leak.

[vristang]

What percent difference between LAMBSE and AFR would you guys accept?

I've pulled up 2 logs that I'm looking at now, and they are close/dead on for most of the tune. It looks like transitions are where there are issues, but I need to stare at it a little more...

[decipha]

1> if you load the flow values for injector off the flow bench as well as the maf values off a flow bench your fuel will still be off by a tad

2> a flow bench has nothing to do with injectors or a curve or anything, a flow bench just measures flow

3>free reving an engine to dial in the maf meter is a very valid means of creating the curve down low, this is maf not speed density, the maf measures airflow, it doesn't matter if your engine is at 2v on the maf at a steady 60mph cruise or if its at 2v on the maf free reving at 4500 rpm, its still flowing the same amount of air

a wideband is not as accurate as a narrowband at finding stoich, a narrowband just measures stoich, you can't really use them to dial in fuel at anything other than stoich, i do use the narrowbands as a backup just to check though, if my narrowband voltage isn't over .8v at WOT then i start snooping around and questioning my wideband

So why on earth would you want to match your afr to an unreliable lambse reading at wot? If narrowbands were so wonderful how come tuners including you and I dont use them on the dyno to tune with?

are you serious? the whole purpose in this thread is to validate that fact, the wideband afr should match the lambse at WOT, thats the afr the ecu is telling it to be at

a narrowband only reads stoich

5> there is only one way to dial in fuel on ford fuel injection or any fuel injection for that matter, make your wideband match your lambse

changing the injector slopes DOES NOT CHANGE LAMBSE

adaptives does not change anything, it only closes the gap from lambse and afr

pw is irrelevelt, thats the beauty of mass air, if the fuel is dialed in at 180kg/hr then its dialed in at 180kg/hr, rpm or pw is irrelevent, fuel is proportionate to airflow the ecu will adjust pw for the rpm to reach the same lambse, thus mass air flow

think of the breakpoint as an amount of fuel, because thats exactly what it is, in the older ecu's with a breakpoint function the breakpoint does actual get effected by rpm but its very minute, this is exactly why you can't convert from a breakpoint scalar to function

in open loop with no kam correction at WOT, lambse1=lambse2




for those interested in the decipha method of dialing in fuel, its very easy to tell if the maf curve is right, at wot with a steady lambse, your afr will stay consistent, if your lambse is at 13 and your wideband afr is 14 but stays there consistent then you know your maf curve is accurate, you can very simply reduce your high slope and get your 14 afr wideband reading closer to the 13 lambse the computer is telling it to be


lambses in closed loop is based purely on the hego feedback, when in closed loop your lambses will just around to hit stoich, once it does adaptives will update the kams, when in closed loop you do not dial in fuel, the kams do that for you, then after you gather suffecient kam data you use that info to dial in your fuel

[EDS50]

So why on earth would you want to match your afr to an unreliable lambse reading at wot? If narrowbands were so wonderful how come tuners including you and I dont use them on the dyno to tune with?

are you serious? the whole purpose in this thread is to validate that fact, the wideband afr should match the lambse at WOT, thats the afr the ecu is telling it to be at

You got me on this one :duh: I was meaning to say c/l and wot came off my fingers as thats what I was thinking ahead about. Yes the afr should absolutely match lambses at wot. I rely on wideband maybe a little more than you do and I would never try to take lambses reading for what they are worth over wideband readings. I just think that wideband readings are way more accurate and report faster than narrow bands ever will since narrow bands really only target stoich and arent worth much else.

[decipha]

a narrowband will report a stoich switch before a wideband will, if it doesn't then something isn't right

[NotchAbove]

I'm more interested in the how, verse why, meaning..if you are not supposed to play with the curve to get afr = lambse and you are not supposed to mess with injector slopes, then what are we adjusting to close the gap.

If I am commanding 12.5wot, and the WB says 10 or 11, how would one go about correcting. THe lambse is commanded based on the tune, it does not change, meaning at a certain temp and load, the lambse will be what it is, the only thing a tuner can do it it give less fuel or more fuel. So how would one achieve this ?

[Scaffy]

By my understanding, those are the only 2 options. You can take decipha's path and adjust the injector settings, or adjust the maf transfer, as EDS50 has explained. Unless I've missed something...