| Author |
Message |
    
Mr2shim
| | Posted on Monday, July 07, 2008 - 10:42 pm: | 
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^^^ Understandable. Me, myself. I did just that. Aiming to kill some of the popping and lower my AFV #. (112 usually) |
Id073897
| | Posted on Tuesday, July 08, 2008 - 03:09 am: |
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However, many people get the impression that they can accurately and safely tune their bikes using just ECMspy, MLV, VEA, and the single NB O2 sensor. The simple fact is that you can't.
Just out of curiosity: why not?
Why is some tuber able to run from one carb without dying instantly, as the two cylinders differ much more in temperature than the fuelframers?
Why would two cylinders of same displacement, same stroke, same bore, same headers, same valve timing, same intake manifold differ such heavily in their fuel needs that it seems impossible to run them from the same map?
Regards,
Gunter |
M1combat
| | Posted on Tuesday, July 08, 2008 - 03:37 am: |
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I'm not sure anyone is saying it's impossible... Just not "tuned"  . |
Id073897
| | Posted on Tuesday, July 08, 2008 - 05:19 am: |
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Do you define "tuning" as applying some diffs of unknown origin to maps?
You are working with an assumption, but no one so far told us why this assumption ("keeping the diffs is good") is a valid one.
Another assumption is "same layout needs same fuel" - which is somehow validated by single carb multicylinder engines and many FI engines runnig from just one map.
There are for sure good reasons why the maps differ, but as long as these reasons are unknown, it's not a founded premiss for further conclusions.
Regards,
Gunter |
Alex
| | Posted on Tuesday, July 08, 2008 - 06:57 am: |
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Experiences from hundreds of hours on the dyno with wideband sensors in each header:
The fuel maps from front to rear cylinder differ pretty much on a correctly tuned Buell engine with fuel injection. Most carburated Buells suffer from different air-fuel charge within the two cylinders. That´s normal for a 45° V-Twin with one common crank pin breathing through a common induction system. That´s it.
Regards
Alex |
Glitch
| | Posted on Tuesday, July 08, 2008 - 07:01 am: |
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Good points Gunter |
Bombardier
| | Posted on Tuesday, July 08, 2008 - 08:01 am: |
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The issue of temp differences relates to areas other than high speed.
The cooling/head temps may be the same at speed however will vary greatly when riding through traffic.
This is the area in which this bike seems to have its rideability issues if the posts on this and other forums are anything to go by.
The standard cooling/maps seem to work fine on my bike on the highway only to cause issues when riding through traffic.
I am not saying the air entering the two cylinders are of a different temperature.
I am saying that the residual heat of the two cylinders will be different due to their differences in environment( one cooled more than the other ).
This will mean one intake charge will be less dense than the other and require a different amount of fuel depending on temperature.
This can be calculated by the ecm and adjusted by it accordingly in percentages.
This assumes that the head temp sensor is reading correctly.
As has been noted by others the sensor may not be registering a fault code but still may be not reading correctly or has 'shifted' which is a BMC term in the service manual.
I do agree with the wide band sensor for tuning but think the heated narrow band sensor is the best for day to day use.
My opinion. |
Id073897
| | Posted on Tuesday, July 08, 2008 - 08:31 am: |
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Experiences from hundreds of hours on the dyno with wideband sensors in each header:
That the front map is a result of a mapping process meets my expectations.
The fuel maps from front to rear cylinder differ pretty much on a correctly tuned Buell engine with fuel injection.
Are these diffs constant? When one cylinder gets it's fuel modified, (how much) will this affect the other one?
If I got that right, then either air or fuel gets "freeloaded" by one cylinder, therefore it's missing at the other. Knowing the exact amount would then help in estimating the change of fuel for the non-monitored cylinder.
Regards,
Gunter |
Alex
| | Posted on Tuesday, July 08, 2008 - 11:27 am: |
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I didn´t mean that the stock maps vary from front to rear (as a result of Buell´s mapping effort) but that the maps that I develop on my dyno for my engines vary from front to rear proving the long known theory of the Buell/Harley engine filling its cylinders pretty uneven.
I can´t tell You if the difference is somehow constant as I don´t really care if it is. I put two sensors on the bike and spend about two to three days on the dyno to get the mapping right for each cylinder. Time after time.
There may be a baseline in difference but I think there are too many variables to call it a constant difference.
So to be honest I don´t think that You can get a perfect map by only monitoring one cylinder. Even if You knew the difference in volumetric efficiency between the cylinders for every cell in the map You could theoretically calculate injection timing but You would still not know if the A-F-value was the same. For example a little difference in the injectors fuel flow could mix things up easily.
So measuring seems to be the way to go. At least for me.
Regards
Alex |
Id073897
| | Posted on Tuesday, July 08, 2008 - 12:40 pm: |
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So measuring seems to be the way to go.
I think we all agree in this.
Well, would have been to easy ...
Regards,
Gunter |
Slaughter
| | Posted on Tuesday, July 08, 2008 - 01:00 pm: |
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I am another who MUST add concerns about not measuring front/rear air/fuel.
IF you are changing anything that MIGHT affect scavenging or flow in any way (pipes, cams, valves) - or intake mods, and you can't get a map from somebody who HAS measured both front and rear with those same mods, you can't afford to just guess.
I've FINALLY watched ECMSpy in action this weekend at Road America and it is truly an AMAZING asset. HOWEVER - you are taking on some risk if you're making assumptions on how your motor is going to run after modifications without going to a dyno or getting a map from somebody with the same cams/valves/pipes/intake.
Incorrect assumptions can hurt.
...OK - I'm whining at everybody again - but there's NO FREE LUNCH - and ECMSpy is a great resource but doesn't mean you can't do your homework! |
M1combat
| | Posted on Tuesday, July 08, 2008 - 01:56 pm: |
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Agreed with all that .
BTW - I wasn't meaning that "tuned" was using this method or using the same map as the rear , I was implying that "tuned" meant the use of an O2 in each cylinder.
What would be nice though is to find a way to get a system streetable and relatively safe (from a lean point of view) without having to buy the extra equipment (like the WBO2's and stuff). I'm not looking for a "perfect tune". In the long run I'm looking for something I can use to generate a decent useable map for an 88" street build. Once I have that I'll work on getting it "tuned". |
Swordsman
| | Posted on Tuesday, July 08, 2008 - 02:10 pm: |
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LOL, I just want to get rid of my sub-4k rpm stumbling! The thing runs like a scalded cat on top end, but I spend most of my time puttering down the road, and it's annoying!
~SM |
Mesozoic
| | Posted on Tuesday, July 08, 2008 - 04:47 pm: |
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Gunter keeps avoiding the question, possibly rightly so, but when is ECMSpy going to be compatible with the latest reflash of the '08 models? |
Xl_cheese
| | Posted on Tuesday, July 08, 2008 - 06:11 pm: |
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Has anyone else noticed their studdering is less prominent when the bike has a full tank? |
M1combat
| | Posted on Tuesday, July 08, 2008 - 09:06 pm: |
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Has everyone with stuttering replaced their plug wires or made sure they aren't arcing? |
Bombardier
| | Posted on Wednesday, July 09, 2008 - 06:14 am: |
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Have noticed that the fuller the tank the better it runs.
The service manual has a diagram of the fuel pump and it shows a low fuel level pressure regulator.
I am guessing but as the pump already has a fuel pressure regulator this additional regulator must have been installed to combat a known issue with fuel pressure at low fuel levels.
Perhaps this regulator is not reading correctly and is causing the low level issues.
Is it possible the different length exhaust headers are the main reason the front and rear maps are so different?
If anyone has a Force system could they chime in and let us know if the bike ran better after the install particularly in the sub 4000 rpm area? |
Opto
| | Posted on Wednesday, July 09, 2008 - 07:53 am: |
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Very interesting reading in this thread. Thank you very much for your input Alex, that is good advice for tuning a motor that is not easy to tune.
After tuning each cylinder individually, with the stock ecm (Ecmspy and MLV VEA), I am running open loop all the time and have eliminated rideability issues, and retained good power and fuel economy. Running closed loop and AFV shifting seems to cause more problems than it solves during tuning. If the engine is tuned properly, I feel it is not required.
If you get an O2 bung fitted to each header to tune each cylinder, you still only need one O2 sensor, as you can only log one cylinder at a time (with Ecmspy).
To those who are thinking about fuel and cooling issues, have a look at the warmup enrichment table in Ecmspy, that shows you how much extra fuel the factory (or ecm tuners) think the engine needs depending on engine temp. Also, stock XB ecm's have a 2% bias for more fuel towards the front cylinder, that is added on top of the fuel maps, I have not measured it but that is how I read it.
For 08 XB owners I think support from Ecmspy has been discontinued as the ecm makers keep moving some of the data around to different places inside the ecm, making it difficult to keep Ecmspy updated. But using the eeprom for editing will work if you are into computer/hex stuff or know someone who can do it.
Ian.
(Message edited by opto on July 09, 2008)
(Message edited by opto on July 09, 2008)
(Message edited by opto on July 09, 2008) |
Mesozoic
| | Posted on Wednesday, July 09, 2008 - 11:56 am: |
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I feel like an ••••••• now. Gunter and the folks at ECMSpy have been working on figuring out the '08 data address locations already as evidenced by their webpage. Sorry, Gunter... I'll shut my trap now.  |
Mesozoic
| | Posted on Wednesday, July 09, 2008 - 12:04 pm: |
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Just double checking my EEPROMs to see if it was ever the "early" version with different mapping and it seems to be the case. My bike's build date is August 2007. According to ECMSpy's docs, "Some early 2008 models (XB only as far as we know) got equipped with an ECM type OD0CB or OC0C9 with a different data layout."
The stock EEPROM on my bike was OD0CB and after the reflash, the version is now YD0L4. However, OD0CB was legible in ECMSpy whereas the new one is not. |
M1combat
| | Posted on Wednesday, July 09, 2008 - 06:01 pm: |
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"If anyone has a Force system could they chime in and let us know if the bike ran better after the install particularly in the sub 4000 rpm area?"
LOL .
Oh wait... Still LOLING !!!1!11!!!1!!!!11!
Sorry .
No, the Force pipe will NOT make the bike run better sub 4KRPMs . The power is MURDERED below 3400 with a Force pipe (the full setup including header).
I never tried with just the "muffler" though and I think it would work ok. Not as well as a Drummer though. |
Bombardier
| | Posted on Thursday, July 10, 2008 - 12:47 am: |
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Using this pipe as a suggestion as it claims to have equal length primaries.
Logic would indicate that if the upstream of the cylinders are the same then the items beyond the exhaust valve may be the issue.
Tuned length headers are something that have been around and used for years on engines so it would seem logical to apply the same knowledge to this engine.
The fact that the standard exhaust uses a butterfly valve to make the exhaust length longer for the midrange seems to suggest that lengthening one primary to the same length as the other would not harm performance as you suggest M1.
Perhaps the design of the Force is the issue rather than the concept.
My 2 cents ( up to about 54cent so far I think) |
M1combat
| | Posted on Thursday, July 10, 2008 - 01:30 am: |
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I whole-heartedly agree . I certainly wasn't making an effort to attack the concept.
The thing is... You can achieve specific results by having headers of different length. Widening the power band is one of them. |
Mr2shim
| | Posted on Thursday, July 10, 2008 - 06:04 pm: |
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So I was looking at an 1125 today and it has an o2 sensor on both pipes! GASP. Too bad the ones who suggest doing such a mod to our beloved XB is breaking down and handing out their super secret knowledge on how to achieve such a feat....
(Message edited by mr2shim on July 10, 2008) |
Xl_cheese
| | Posted on Thursday, July 10, 2008 - 06:12 pm: |
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FYI - I've ordered a 2nd xb12 pipe that I plan on installing a 2nd bunghole on.
When I'm done playing with it I'm going to put my current pipe back one.
I'd be willing to pass the modified header around if anyone is interested. You'd pay shipping of course. |
Mr2shim
| | Posted on Thursday, July 10, 2008 - 08:39 pm: |
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You'd trust someone with a pipe for only the price of shipping and no other grantee they'd return it?? LOL |
Alex
| | Posted on Friday, July 11, 2008 - 06:41 am: |
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Mr2shim,
the super secret knowledge of getting two o2-sensors on the header is.......
.....bore a hole in the front header and weld a sensor bung to it. That´s it :-) . To move one step further I even weld another bung in the rear header making the header a "three-bung-supernatural" construction.
To be honest I really do it like that but the two additional wideband sensors are only used when I have the bike on the dyno. After tuning the sensor holes are plugged. There is not much sense in trying to use an additional small band sensor for the front header like the 1125 does for one simple reason: the 1125 ECU monitors each sensor and has two AFV values. One for each cylinder. The XB ECU does not have the capability to monitor a second o2 sensor.
Regards
Alex |
Xoptimizedrsx
| | Posted on Sunday, July 13, 2008 - 04:29 pm: |
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note. lots of dyno time and only a wide band O2 reader will only get 2/3 the way tunes. you have to be able to read a 4 gas value to get the whole picture. i can set your fuel spot on yet still lack power. yes it will be a lot better but if you uses a 4 gas in which one is a wide band o2 and other gasses you will net a timing change thats able to get the co2 mix correctly divided between the cyls. then as the co2 moves the fuel value moves. you may actually be too rich in areas when the correct co2 mix is reached.
i have seen it many times i actually have to move timing up in a few areas on all buells to get there co2 correct. and when it moves to the .10 i like the fuel is too rich then so i have to back fuel down and reset the co2 again. then reset the fuel. its a lot of steps but you net a much more perfect map and motor function.
the myth of a wide band only boggles my mind. as there is not a nhra team out there who only rely on wide band. its just one tool.
it wold be like saying your a mech if you only one one socket set. for tools.
there is a little on this 4 gas system online. just search 4 gas dyno tune
and 4 gas analisers. they are expensive but well worth it.
dont trust wideband alone. its really not a whole lot better than NB 02 readings if you dont have a complete picture.
i get my tuning fron years of working on engines. from the drag track and circle track.
remember to never tune on the rainy day for a fair weather rider. it will throw off the map on the water drops per pound of air.
as this is outside the 4 gas its all a requirement to get a maxium tune reading. this is why drag race teams store every data they can on temps of the track to the air a complete weather history. then they have it to fall back on for other tracks on setting there cars tuning up for the correct day and weather.
again a wide band is not enough tools to read the whole picture. it can and will create a mis guided map just as a NB 02 will. a 4 or 6 gas analizer will do the trick. as it allows you to set timing points and fuel for the mix of both will create the picture.
a bad running bike with less time money and all. freeing up ride time. and if you race money saved as i have two bikes that i tuned with the 4gas. that have stock engines running in the 10.5's at the strip. both are 2005 xb12 bike my friends have in arizone and indiana.
mike |
Glitch
| | Posted on Sunday, July 13, 2008 - 07:34 pm: |
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Mike, is xoptiinside your website? |
Glitch
| | Posted on Sunday, July 13, 2008 - 07:38 pm: |
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Yes I guess it is, all I had to do was look!
 |
Siam_uly
| | Posted on Thursday, April 02, 2009 - 01:09 pm: |
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For those who don't agree with the fixed factor increment method ( adding 2-3 pule width) to get a front fuel map, here is a small Excel application that I have developed to calculate the front map based on the ratio between the stock maps.
The spreadsheet modify the tuned msq file ( from MegaLogViewer ) and add the new calculated veBins1.
The application is not bullet proof but does the job for me.
Regards,
Serge |
Buell Front Map Maker