SEPST question

[05FLHTC]

New to EFI so go easy on me please 

My cousin has a new 2011 ultra limited, stock other then a replacement 2 in 1 into 2 pipe along with a set of slip ons.

Bone stock it was running hotter then Casey's nutz & occasionally going into parade mode.

So being as though he is gonna eventually replace the OE cam with a SE204 he purchased the SEPST software & cables.

It took us a while but we managed to down load a new calibration file 009FZ002.

The bike runs smooth mpg is about 35ish, not terrible not great. Starts fine and appears to be running considerably cooler. I know it's hard to read plugs with today's fuel but we will prolly give a look see at em anyways.

Ok finally getting to the question:

Using the SE tuner software level 9 (see attached photo) there is a fuel selection for ethanol percent. Does this do what I assume & really adjust the closed loop to different values? 

The three selections in the drop down box (hope you can see it in the photo) include:
AFR 14.6 for Gasoline
AFR 14.3 for gasoline with 10% ethanol
AFR 13.5  for gasoline with 26% ethanol

TIA & be NICE!  Even an ole dog like me is trying to learn something new...

[attachment removed after 60 days by system]

[Jeffd]

the way I understood it is it just telling you what stoic is for those fuels and that is where it will adjust to depending on what fuel you are using.

[glens]

I'm positive those different "AFR" numbers are informational only.  That's to say they're only for the eyes and brain of the human looking at the fuel table in the software.  When it comes right down to it, the ECM is really working with lambda anyway and it doesn't matter what fuel you've selected to display in the software.  This is just another example of why using lambda values instead of "AFR" values is better in the long run.  If we can train our minds to think in terms of lambda then every bit of this confusion completely disappears.

[05FLHTC]

Simple question am I changing the closed loop target or NOT?

[wurk_truk]

No.

[Dennis]

I opened a calibration and changed to 10% and the values change in the AFR table but going back to lambda it appears nothing changed. although it did change the values in the "Display as air fuel ratio" view.  I don't think it corrects for ethanol but I could be wrong.

[strokerjlk]

Simple question am I changing the closed loop target or NOT?

No you are not

[05FLHTC]

Why is it there then?

What purpose does it provide?

[strokerjlk]

Why is it there then?

What purpose does it provide?

what glens said

I'm positive those different "AFR" numbers are informational only.  That's to say they're only for the eyes and brain of the human looking at the fuel table in the software.  When it comes right down to it, the ECM is really working with lambda anyway and it doesn't matter what fuel you've selected to display in the software.

[longshooter]

I'm positive those different "AFR" numbers are informational only.  That's to say they're only for the eyes and brain of the human looking at the fuel table in the software.  When it comes right down to it, the ECM is really working with lambda anyway and it doesn't matter what fuel you've selected to display in the software.  This is just another example of why using lambda values instead of "AFR" values is better in the long run.  If we can train our minds to think in terms of lambda then every bit of this confusion completely disappears.

[/color]

I disagree with this statement and would refer you to page 43 of the Master Tune Guide. While the referenced material addresses the Closed Loop Bias table, it does point to the importance of selecting the correct stoichiometric AFR value for the fuel being used. Currently, the ECM is programed to look for 450mv= Lambda 1.000. If left unchanged, the 02 sensors would be returning, according to the TTS, CLB table a voltage of .786 = to 0.980 Lambda (14.39 AFR). Since this is less than Lambda 1.000, the ECM will interpret the exhaust as "rich" and adjust the fuel leaner. The outcome is obvious .... poor performance, hotter running and possibly engine damage in the long term.

longshooter

[hrdtail78]

Different program altogether.

[ViennaHog]

at the risk of revealing my ignorance I respectfully disagree. Each fuel needs a specific amount of O2 to burn completely.
A stoichiometric burn produces an exhaust gas that has not oxygen left. This low oxygen condition is detected by the O2 sensor and relayed to the ECM.
If you burn an alcohol rich fuel its specific O2 demand is much lower compared to a regular base fuel.
If you run this fuel with a calibration developed  for a base fuel the engine will run rich in open loop.
Within the limits programmed into the fuel control scheme the ECM will try to reach stoichiometric conditions in closed loop.
So I doubt that you have to move the Lambda set point to adjust for the different fuel types.

[longshooter]

Different program altogether.

[/color]

hrdtail,
Having never used the SESPT, I defer to your expertise. This is also why I mentioned my source as TTS. However, the functionality of the 02 sensors remains the same regardless of the tool used to tune.

at the risk of revealing my ignorance I respectfully disagree. Each fuel needs a specific amount of O2 to burn completely.
A stoichiometric burn produces an exhaust gas that has not oxygen left. This low oxygen condition is detected by the O2 sensor and relayed to the ECM.
If you burn an alcohol rich fuel its specific O2 demand is much lower compared to a regular base fuel. If you run this fuel with a calibration developed  for a base fuel the engine will run rich in open loop.
Within the limits programmed into the fuel control scheme the ECM will try to reach stoichiometric conditions in closed loop. So I doubt that you have to move the Lambda set point to adjust for the different fuel types.

ViennaHog,
Please help me understand what you mean in the first highlighted statement. Do you mean to say that alcohol rich fuel requires less oxygen to burn, or do you mean the byproduct of oxygen after the burn which the 02 sensor will "see" is less?

I agree with your second highlighted statement. However, in its factory calibration the ECM would be programmed to attain stoich at Lambda=1.00 or 14.6 afr per the posted SESPT specs. rather than the correct Lambda/afr for the fuel being used. It is this "skewed" Lambda that I believe will have the ECM correcting fuel in a detrimental direction.

I will concede to both of you that I may well be the one who is "skewed". I have only been using TTS and been doing EFI tuning on Harleys for about ten months whereas you have much more experience. I have, however, been involved with fuel management diagnosis and repair in the automotive gas and diesel world so I feel I have a pretty good understanding of how the system works. Please feel free to correct any misunderstanding I may have.

longshooter

[ViennaHog]

  on my side. let me think about it one more time. The alcohol rich fuels require less oxygen for full combustion which in turn means that a base fuel calibration is too lean for full combustion of a blended fuel.

[05FLHTC]

Ok .... and thanks for the replies 

I sure thought it was going to correct for the corn squeezins in closed loop.  I really don't understand what else it could provide but then that should not come as a surprise to anyone here...This is truly my 1st rodeo with this stuff, I am really trying to learn...

[wurk_truk]

It's just a tool that lets you see what the various fuels can do... just for your FYI.  It changes NOTHING in the tune or how the O2s 'read' oxygen, be it SEPST OR TTS.  Longshooter is vastly misinformed if he thinks this changes anything inside of the ECM.  It's a tool, like the CLB tool that converts the CLB to voltage.  Since NO Harley ECM since 2008 reads stoich as 450mv...  its a worthless tool at that.

[glens]

Stoich is still 450 mV out of the sensor, it's just that some system's sensor grounds are floating above 0 VDC anymore so the reported voltage becomes 450 mV plus however much voltage above the bike's ground the sensor's ground is floating.  The floating sensor grounds may be an attempt to thwart voltage dividers in the sensor circuits (though they should still work if properly configured; though this does not mean re-tying the sensor grounds to the chassis as some have done), but I'm more inclined to think that floating the sensors is either an electrical noise filter/control measure or perhaps done to use the voltage-sensing circuitry in a more linear/dependable section of its range.

I'm positive those different "AFR" numbers are informational only.  That's to say they're only for the eyes and brain of the human looking at the fuel table in the software.  When it comes right down to it, the ECM is really working with lambda anyway and it doesn't matter what fuel you've selected to display in the software.  This is just another example of why using lambda values instead of "AFR" values is better in the long run.  If we can train our minds to think in terms of lambda then every bit of this confusion completely disappears.

I disagree with this statement and would refer you to page 43 of the Master Tune Guide. While the referenced material addresses the Closed Loop Bias table, it does point to the importance of selecting the correct stoichiometric AFR value for the fuel being used. Currently, the ECM is programed to look for 450mv= Lambda 1.000. If left unchanged, the 02 sensors would be returning, according to the TTS, CLB table a voltage of .786 = to 0.980 Lambda (14.39 AFR). Since this is less than Lambda 1.000, the ECM will interpret the exhaust as "rich" and adjust the fuel leaner. The outcome is obvious .... poor performance, hotter running and possibly engine damage in the long term.

I'm quite sure you're misinterpreting the documentation.  If you set the CLB at 450, it will be "lambda=1" and this does not change even when the fuel does.  Lambda=1 is achieved at stoichiometric burn.  I'm not going to consult any tables or documentation for this so forgive any error as it's not intended to be anything more than an illustration.  Let's use your numbers from above.  Say you've got CLBs at 450 and have tuned with E10.  If you totally remove the fuel and replace it with E0, the ECM's fuel calculations will initially provide what would amount to a CLB of 786 but the ECM will adjust the fuel to achieve the programmed-for 450.  It will return what started out (this time) as lambda=0.98 to lambda=1, since that's really what it was programmed to achieve.  Even though the fuel table contains AFR numbers, the ECM really doesn't go by them when running closed-loop.  It's effectively using lambda because everything's based on the output of a lambda probe in the exhaust.

05FLHTC:  if you have the option to display the fuel values in lambda and you do so, in the long run this confusion will go away for you.

[wurk_truk]

Glens.  You REALLY need to research sensors a bit better.  These are NOT true lambda sensors...  no way no how.  No way  will these read straight alcohol.  And these DO skew with each step away from straight gasolines 14.68 AFR.

Go start reading all the crap on Bosch's and NGK's sites and get back with that.

Of course, you will NOT do so, because I am a dumbass.

[longshooter]

wurk,

While I respect much of what you post, I also feel you have some misconceptions of how 02 sensors work. Case in point, some time back in another thread, you posted something to the effect of having a concern regarding moving the 02s too far from the original position because they turned off and on and may be too far away when the ECM was ready to poll them. A question of timing. ( Not your exact words but conveys what I read ) Rather than going into all of the 02/ECM poll timing, sensors turning off/on,  throwing in engine speeds and what that would mean to the off/on timing not to mention the ECM is not drawing a gas sample from the 02 area but is relying on a electrical signal which is pretty fast. Well, I guess I did go into it all. I will say this; once the 02 sensors are up to temp and on-line, they are on-line.
What we can see with any tuning tool does not mean the ECM is limited to "seeing" only that for any sensor it monitors.

As for the CLB table, it creates an offset, typically richer, which is applied to ALL tables that affect AFR, both closed and open loop. So, in effect, I would say, Yes it does change things inside of the ECM as that is where the fuel tables reside. You may want to read, or re-read pages 41 thru 43 of the TTS Tuning Guide.

glens,

All I can do is admit that I usually get lost in your verbose and convoluted posts. I will also say that some of what I have read leads me to believe you make a lot of assumptions rather than stating facts or examples of what the system does and why it does it. So, I will refer you to my response to wurk.

For both, I am not in this for a pissing match. I am willing to learn but if future posts smell like piss, this will be my last post to it.

longshooter

[wurk_truk]

Long.  Me and Glens are NOT in any kind of pissin match.  I LIKE Glen and we are simply doing the back-and-forth- ...  ALL trying to learn.

Also, I WILL stand on my stated belief of one CAN move the O2s too far away.  Yes, the do work all the time, but the key MAY be (i did say MAY) when the ECM 'polls' the sensor.  NO sensor is 'on' all the time to an ECM.  The ECM places windows of opportunity and only pays attention to these things at certain times during an engine running.

Polling issues aside.  I don't really care.  Glen IS verbose, but I can read right thru it, and just a difference of opinion between us.

We are ALL wrong at times, and THIS site is THE one to argue and try to seek the truth.

[glens]

Glens.  You REALLY need to research sensors a bit better.  These are NOT true lambda sensors...  no way no how.  No way  will these read straight alcohol.  And these DO skew with each step away from straight gasolines 14.68 AFR.

Go start reading all the crap on Bosch's and NGK's sites and get back with that.

Of course, you will NOT do so, because I am a dumbass.

I looked around on some of the Bosch and NGK websites and didn't find anything about their sensors working better or worse with different fuels.  My take on it is that stoich is nominally lambda=1 and that this represents no extra fuel to burn were there more oxygen to facilitate it, nor no extra oxygen left to facilitate burning any more fuel were it present.  In other words, all the oxygen combined with all the fuel for a complete no-waste (in terms of oxygen and fuel) burn.

I guess you have in mind the extra oxygen the alcohol fuels bring to the table, but it doesn't matter where the oxygen comes from, does it, so long as all the fuel has burned and no extra oxygen remains?  Isn't that the definition of lambda=1?  So why wouldn't the lambda probes a.k.a. oxygen sensors perform exactly the same for either "pure" gasoline, straight alcohol, or any suitable combination?  Hey, you know me, I love to do research.  Got any direct pointers to available (on-line) information regarding this proposed matter of differing sensor behavior for different fuels?

[longshooter]

wurk,
It really is of no concern to me how you and glens interact. Or anyone else on this forum for that matter. What does bother me is the rudeness and disrespect I sometimes see here, not necessarily you, but in general. Having no control over that however, I can only guard against getting pulled into a pissing contest, which is what I was referring to in my previous post.

I will agree that the 02 sensor can be moved too far in the respect that if it is too far downstream, exhaust reversion could pull in oxygen and affect 02 feedback. As for when the ECM polls the sensor, I'd say it's pretty much all the time. Let's consider 3000 engine RPM. For each injector, the ECM is getting feedback from the sensor, determining if an adjustment is required to pulse width, how much adjustment and fires the injector. That's 50 times a second per injector. The ECM is a substantially powerful processor.

I agree that we are ALL wrong at times. I disagree that THIS is THE site to argue. I try to make my posts clear enough to be understood and NOT open to interpretation. I do not always succeed. I will agree this is THE place to seek the truth. In that vein, can you direct me to any documentation for your statement about the ECM placing windows of opportunity and only paying attention to these things at certain times during engine running? I will concede that the MAP sensor is treated this way at "key on" to establish BARO but I am not aware of other sensors being being treated this way.

Thanks in advance.

longshooter

[longshooter]

glens,
If your take on Lambda is correct and there is no unburned fuel and no oxygen in the exhaust, then what are the 02 sensors reporting to the ECM? You may want to consider that oxygen is a by-product if the combustion process.

longshooter

[wurk_truk]

Offline Steve Cole

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Re: FUDGE THE KOOLAIDE- Time for some Whiskey Tuning
« Reply #90 on: Yesterday at 09:27:31 PM »

    Quote

I think most here will agree that they now understand there is reversion going on in the exhaust. So WHEN you read the sensor is a big deal based on it's position in the exhaust and the reversion. The stock ECM reads the sensors once per firing cycle at ALL RPM's, does the TS? How does the TS even know when the cylinder being read was fired? It doesn't! The reads of the stock sensor are timed to the firing cycle, is the TS? There is so much more to what is going on when you try to do this on the street that your just not going to be able to cover with the TS but there are some that believe you just toss it in the exhaust and it's right and everything else is wrong. 




Quote from Steve.  I don't have time to dig it up.  But ir DOES only read once and that 'once' is 'timed'.

[glens]

I will agree that the 02 sensor can be moved too far in the respect that if it is too far downstream, exhaust reversion could pull in oxygen and affect 02 feedback. As for when the ECM polls the sensor, I'd say it's pretty much all the time. Let's consider 3000 engine RPM...

How far downstream in the exhaust plumbing and the resultant extended opportunity to sample diluted exhaust is manageable to a certain extent by the timing of the sensor polling in the ECM's control loop.  The sensor may well be monitored at several discrete timing points within an engine cycle; close to continuous but not quite.  Choosing via the programming which spot to use the information can ensure success or failure.  More on that train of thought in a bit...

I will agree this is THE place to seek the truth. In that vein, can you direct me to any documentation for your statement about the ECM placing windows of opportunity and only paying attention to these things at certain times during engine running? I will concede that the MAP sensor is treated this way at "key on" to establish BARO but I am not aware of other sensors being being treated this way.

It's not just at "key on".  There's a table to determine when "BARO" can be checked during "normal" engine operation as well.  Consider also a TTS cam tune log file.  Note all the various MAP values offered in any given time-slice and later how choosing one over the other within a calibration results in differing reported idle MAP values, for example.  The MAP sensor is indeed polled at several places within an engine cycle and which poll timing to rely on as the "standard" is important for getting the engine to run well and differentiating between load and overrun conditions.  There's no reason whatsoever to believe any other sensor in the ECM's arsenal couldn't or wouldn't be treated similarly.  Including and perhaps especially the O2 sensor as well.  This is a major reason why I'm not a fan of the V&H pipes which relocate the O2 sensors from where they are stock, regardless of whether the bung configurations are otherwise correct or not.

glens,
If your take on Lambda is correct and there is no unburned fuel and no oxygen in the exhaust, then what are the 02 sensors reporting to the ECM? You may want to consider that oxygen is a by-product if the combustion process.

Not pissing at you or anything, but really?  Oxygen a byproduct of combustion?  Oxygen is present in the air mixed with the fuel, and in some cases also in the fuel itself.  My research has led me to understand that the oxygen is recombined with some of the other elements present prior to combustion as a result of the combustion, but not that O2 gets "freed up" (formed as a byproduct) as a result.  What I've seen is something more like: 25/2 O2 + C8H18 -> 8 CO2 + 9 H2O

The lambda probe is merely a unique structure which results in O2 migration through it producing a DC voltage.  The rate at which the O2 is trying to equalize (don't know if that's the best word) from the outside of the probe to the sample side determines the sensor output voltage.  The extent of the oxygen deficiency or surplus at the sample side is what's getting measured by the ECM.  It really doesn't take intimate knowledge of what's going on at the molecular level (knowledge I'm admittedly lacking) to understand what's going on well enough to use it for our present purpose.

[longshooter]

glens,
         " The sensor may well be monitored at several discrete timing points within an engine running cycle;"
Another of your assumptions?

I know about the table for taking BARO readings at various TPS positions. I merely cited the one example at " key on ".

" There's no reason whatsoever to believe any other sensor in the ECM's arsenal couldn't or wouldn't be treated similarly. Including and especially the 02 sensor as well ".
I am looking for facts, not assumptions.

" Oxygen a byproduct of combustion? "  Absolutely. The following is a list of some of the emissions from an engine:

CO2 - carbon dioxide
H2O - water vapor
CO -carbon monoxide
NO & NO2 - nitrogen oxide & nitrogen dioxide, commonly called NOX

There are also N2 - nitrogen gas and,
Hydrocarbons from unburned fuel, commonly called VOCs, Volatile Organic Compounds

longshooter

[wurk_truk]

I had thought that you would take Steve's word on this.  But...  Doesn't matter.   Some damn place...  Maybe some PMs from FBRR?  The O2s don't read continuously, so there simply IS a time during the combustion cycle that they read, or don't read from the ECM.

[longshooter]

wurk and glens,

I guess these are a couple of points we will just have to agree to disagree. In the end, we will continue to do what works for us. I know I will until I am shown a better way.

Thanks for your participation ...... made me put on my thinking cap a couple of times. Not a bad thing to do every so often.

longshooter

P.S. wurk, good luck with your wideband/broadband project. I am following that thread with interest. Should be enlightening to see how the results stack up to the narrowband results if that is something you will be doing.

[glens]

This may come across as pissiness and I suppose it is (was), in part.  It's a little difficult to actually post now after the previous post by longshooter late this morning, but I'd started it late last night and wanted to go ahead and just put it out anyway, so please don't think I'm just trying to get the last word or anything.  Any time we can all come to a more complete understanding of what's going on, we'll all benefit.

glens,
         " The sensor may well be monitored at several discrete timing points within an engine running cycle;"
Another of your assumptions?

Just like my assumption that the MAP sensor has firmware-selectable poll times and suggested (right here in these forums, I assume) that TTS software provide a way to choose between them, prior to the appearance of cam-tune?  What's your point?  You have some history in automotive fuel management diagnosis and repair.  Did this extend to modifying the low-level code or selecting variables used by it running in the ECM?  For not wanting to get into pissing matches you stir stuff up pretty good.

At any rate, Steve Cole's quoted statement regarding the timing of the O2 sensor polling surely isn't based on any assumptions.  Assumptions or no, what would you like to do with the information regarding sensor poll timings?

I know about the table for taking BARO readings at various TPS positions. I merely cited the one example at " key on ".

" There's no reason whatsoever to believe any other sensor in the ECM's arsenal couldn't or wouldn't be treated similarly. Including and especially the 02 sensor as well ".
I am looking for facts, not assumptions.

Your statement regarding alternate use of the MAP sensor was ambiguous.  It left room for the assumption that you were saying key-on BARO determination was the only alternate polling of that sensor as compared to, say, "continuous" monitoring during "normal" engine operation.

You were given in another post a fact regarding the O2 sensor poll timing, even though there's nothing you can do with the information aside from ensure the O2 sensors are located and mounted equivalently to stock in order to maintain best use of them by the ECM.

So we currently know that both the MAP and O2 sensors have specific poll-timings at discreet points in the pertinent engine cycles.  Both of these sensors are extremely fast-acting and readings taken from them at various times will provide various results.  The air and engine temperature sensors probably are not capable of such low-latency operation but those are not low-latency parameters.  How about the Ion Sense mechanism?  That's got to be very timing-critical in the ECM's code flow, too, I assume.

" Oxygen a byproduct of combustion? "  Absolutely. The following is a list of some of the emissions from an engine:

CO2 - carbon dioxide
H2O - water vapor
CO -carbon monoxide
NO & NO2 - nitrogen oxide & nitrogen dioxide, commonly called NOX

There are also N2 - nitrogen gas and,
Hydrocarbons from unburned fuel, commonly called VOCs, Volatile Organic Compounds

I'll give you that; oxygen is indeed still present in various combinations with other elements as a result of non-optimal combustion, but it's totally immaterial.  I believe all we're concerned about in terms of what the lambda probe can use is the dioxygen (O2), which is not a "byproduct" of combustion unless it's been freed up from more complex molecules by the combustion and not used because there wasn't enough fuel.  But hey, that's just an assumption on my part...

NOx can be NO1, NO2, NO3, etc.   Hence the "x".