| Author | Message | ||
     G4string |
So I started reading through the "ECM Tuning Notes for Buell DDFI and DDFI-2 2nd Edition" (found here - http://xoptiinside.com/tuning_guide). This is my 1st step at starting to learn and understand the tuning process. However, after reading it, I must admit I have some questions as to why we need tune in regards to the way the ECM actually works. Hopefully, I know enough to explain myself and state my questions in a way that makes sense; So as I understand it, and the way the manual states it, the ECM found on all Buells operate under 4 conditions; close loop (CL) close loop learn (CLL) open loop (OL) open loop wot (OL WOT) The book states that ALL ranges are defined by TPS position and RPM. This would mean that there are definitive boundaries for all 4 modes. Easy enough.... During close loop, the o2 sensor is in charge of maintaining the proper AFR. It is striving for a stoich mixture. In CL, the ecm will automatically adjust itself to maintain stoich. In CLL mode, the same things apply as in CL mode. However, in addition to that; the ecm is setting it's adaptive fuel value. The AFV is what is applied when operating out of the CL range. In the OL mode, the AFV values are put in place in lieu of the o2 sensor monitoring ego. Since the AFV is "adaptive", vaules can/will change. However, (if I get this right) the value will only change unless the ecm goes back to the CLL range. At that point, the ecm obtains/updates the AFV parameters. In OL WOT, same thing happens as the OL mode except ecm will create a more rich mixture for power where OL is more lean to decrease popping on decel, for effective engine braking, and to ensure a quick return to idle. What I dont understand is that if the ecm is always learning and adjusting, then why do we need tune it?? I mean, while in CL and CLL mode, we "should" have no worries as the ecm is in continuously monitoring ego and making the needed corrections as need be. During the moment that you drop in to the CLL mode, the ecm is setting up the AFV. The AFV that the ecm just learned is "today, in the moment, right here, right now" specific. So why wouldn't the AFV parameters be good enough for fuel metering when one is out of CL mode. After all, the ecm just learned it? So the way I see understand it, what good does tuning do us after intake and exhaust mods if the ecm has the capability to compensate for the changes we made with said mods?? I am confused.....please help me understand!!! | ||
| Xtremelow |
My 2¢ We need the tunes more or less as a baseline as our bikes due self learn they can only do so to a certain point within legal restrictions. | ||
| Vospertw |
G4string, I'm at the same stage (not really - I haven't read the guide yet) as you. Except for a little roughness riding near idle - which I could care less about since I rarely do that - my 09 has been one of the best running bikes I've had. The FI is far smoother at low RPM than my 99 GS. My "normal" ride is from sea level to 6000' and back and except for the normal loss of power due to altitude, I've never noticed any lack of smoothness, rough running, etc. Bike is stock except for the 2010 XB RSS and ECM flash. Maybe I need to ride a well-tuned XB to see what I'm missing? | ||
| G4string |
So I spoke with Al at American Sport Bike. I have to say, I am still confused as to why we need to tune in CL and CLL mode. One thing he mentioned was that CL and CLL tuning were the most important areas to tune. To me, this made absoltuely zero sense. I mean, why tune in an area that is constantly adjusting and tuning itself. We did talk about some wideband/narrowband stuff. That stuff makes some sense. He did mention that one of the best ways to tune with a single narrowband o2 sensor is getting a preadusted map with your mods already logged....and then fine tuning the CL and CLL areas. And again, that makes sense. What I am still strugling with is understanding why tuning in the CL and CLL areas is the most inportant and even necessary? Sorry to be a stupid PITA....but f***, I just dont get it. | ||
| M1combat |
The AFV adjusts the MAP up and down. Not each cell. So... With the stock setup you have a specific VE (Volumetric Efficiency) curve. Once you change something the VE curve changes. The AFV only adjust the stock curve (with a stock map anyhow) up and down. So... Say you throw a Drummer (I highly recommend them) on it and settle the AFV at say 3200 it will indeed settle to stoich mix just like it did with the original exhaust. Now... Say the Drummer wants 2% more fuel at 3200 than the stock setup, but 4% more at 5500 than the stock setup. It adds 2% by settling the AFV at 3200, but when you get to 5500 it's 2% lower than it needs to be because it still thinks the stock pipe (stock map) is on it. Anything else? | ||
| M1combat |
The solution is to map the entire learning area to Stoich at whatever AFV your bike likes to run at the altitude you run (I think mine stay at like 95 or something because I live in the mountains). Once you have that done (with the O2 correction disabled so it doesn't move the AFV around) then tune the rest of the map to whatever you'd like. One note... Many people feel that setting the AFV to 100 and disabling the O2 correction is the right way to start. I disagree. That would work fine if you tune the bike at whatever altitude Buell decided should correlate to a 100 AFV, but if you are higher or lower than that you should use the AFV your bike likes to be at. You can use 100 all you'd like and I don't think there's an issue with fueling in general, but what you're doing is skewing the altitude range that the AFV numbers correspond to. So... You MIGHT get to a place where your AFV reaches the limit of it's adjustability in one direction or the other. So... If you KNOW there's nothing wrong with the engine and you KNOW that at your elevation with a stock setup you'd see a 92 or a 104 AFV... I propose you use THAT AFV while tuning  . | ||
| Krueger08xb12s |
Don't forget about climate changes. It's not just altitude, but also air temp and humidity that affects air density and your afv | ||
| G4string |
"Don't forget about climate changes. It's not just altitude, but also air temp and humidity that affects air density and your afv." Climate changes affect the stock map, right. The ECM adjusts for climate changes automatically....I dont see this is a specific reason to tune. If that was the case, riders with stock maps would need to tune everyday day because the weather changes day-to-day "The solution is to map the entire learning area to Stoich at whatever AFV your bike likes to run at the altitude you run (I think mine stay at like 95 or something because I live in the mountains)." This is exactly what I am not getting. I thought the ECM in cl-learn mode was going to run stoich no matter what with the help of the o2 sensor (or as close to as possible, thus the lambda sensor).....and then it adjusts the AFV from the values it learned. Does the ECM automatically adjust itself to run as close stoich as possible while in cll mode????} (Message edited by g4string on August 25, 2010) | ||
| Buell_41 |
The base map in the ECM can only be changed by re-flashing. Climate, altitude, engine load, engine temp., etc affect the AFV. If the map and the AFV followed eachother you'd always be at 100. The AFV is an acquired variable that the bike decides on which may be above or below the base value in order to maintain stoich for your specific setup and riding style. So some poeple have an AFV of 95, 102, 100 whatever. G4string's question is a good one... Thinking out loud here but what if the bike only gets the AFV it needs for the cell its currently operating in? By that I mean each time you move to another cell, its always having to learn and apply the correct AFV... even if you return to a cell that it previously "figured out" There's a time lag where it would have to figure out the value. But if you go into the map and modify that cell (or cells) so they are closer to what the bike keeps wanting in those cells, you don't have to "wait" for it to adjust. Did that any even a bit of sense? Kinna did in my head... I think... | ||
| Brightbuell |
I like that thought. Makes sense. The less time the ECM spends adjusting to its desired #, the more time its running great, or at its best. | ||
| Xoptimizedrsx |
the trick..... stabilize the afv. if you have an AFV at 80 or 130 it really does not matter as long as its persistent through out the entire map. so let i ride my bike at 2700 rpm and the afv is 90 and 3200 its 90 but at 4000 it 100. the issue is not the 90 its the 100 because at 4500 again the afv is 90. so to fix the problem my fastest way is adjust the 4000 fuel up till the afv is also a 90. this is smoothing. the 90 is the true base fuel to be stioch. 14.7:1 +-.1 afr... the fuel also is adjusted from map(where applicable),air intake sensor and engine temp sensor. this is besides the O2 sensor. if the o2 functioning the sensor is only a report tool reading how much oxygen is in the pipe. not how much is in the cylinder during and after the burn. the misconception is the sensor is locked to 14.7 on a nb.. it's not it has a range it works best in where 14.7 is a government mandated setting due to pollution. the sensor can work fine as low as 14.0. It's just not posted very much and a lot of the places were required to remove the postings. makes you wonder. so if my afv is 90 at 14.7 and i change the o2 target (used to set global fuel) to 14.2 my new afv will rise aprox. 1.5 points per .1 change. new afv= 90+7.5= 97 because the ecm will drop all dec in this degree to zero untill it hit. 97.6 which will read 98 afv. so over all the number does not matter on the actual afv as long as its persistent as stated earlier. the cl loop uses a static adjustment based on live data. locket to target O2 setting. adjusted from the ego reading balanced to the map values and the acceleration position and rate of change. ego= afr/traget~ afv+ tps  2 do this per cylinder. and if the cylinders are off from one to the other you get the bucking feeling. low power. poor mileage. the biggest issue is mis matched afr between the cylinders not the lean or rich conditions most people complain about. you can run fine very lean and very rich as long as the target o2 voltage is set to that value and the cylinders are matched. the leaner the more accurate the match has to be to not feel any surging or bucking. try it and test it you will find the same results... written on the fly but you get the point i hope. its more about balance than afv or afr. leaner less power richer more power. why ride at no load cruise 13.0/13.2 full power gasoline N/A. when 15.2 will do just fine and give you a boost in mileage with out any heat issues. fuel burns the hottest at 14.7. at 15.2 it burns cooler. more air flow less burn less heat. timing is the issue on heat 99% of the time. leaner runs less timing with equal HP/tq to a point. you will see these results on a static dyno which 99% of the shops dont have a way to test static load on the engine for setting timing. my 2.68 cents... remember balance between the two. treat each cylinder as if its the only one.. no balance, no power,mileage or nice ride. xopti!!! | ||
| Al_lighton |
The CLL domain map determines how the AFV learns. If the CLL map is off, you won't have AFV stability, and that will affect how it runs in Open loop, regardless of how well open loop was tuned. That is why CLL is so important. Here's a kinda simplistic way of looking at how the AFV learns. At each operating point within CLL, the amount of fuel that is needed for stoich as determined from closed loop operation, is compared to the amount of fuel that it calculated from the map for the same operating point (even though it isn't RUNNING on the map). That is the "instantaneous AFV". The long term average of all of these "instantaneous AFVs" is the real AFV. It's a rolling average, the AFV is ALWAYS learning in CLL. If the "instantaneous AFV" is being set differently at different RPMs, because of different mismatches between the map and the O2 CL derived values, the AFV won't be stable, and the open loop map derived fueling will be scaled by this unstable AFV. So the bike will always run inconsistently in open loop operation. OTOH, if the CLL fueling AND the map derived fueling match stoich across all of CLL, the AFV will be stable. The goal is to tune the map so that at sea level, the map AND the O2 sensor both will yield stoich, and that the AFV will stabilize at 100% (i.e., no up or down scaling of the map at sea level). Read what M1 said again about the effects of intake and exhaust configurations at different RPMs, and you'll understand why the map has to be changed by different amounts across CLL to yield an AFV of 100 consistenty at sea level. AL | ||
| Al_lighton |
If you consistently tuned it rich over all of CLL, the AFV would learn down. If you tune it lean over CLL, the AFV will learn up. If you're tuning with wideband O2 sensors and tune by the Air/Fuel ratio (AFR), you tune CLL to 14.7:1 regardless of altitude. But if you use the loop to tune the Adaptive Fuel Value (AFV) directly, you SHOULD tune the AFV to the normal AFV for the altitude that your dyno is at. If you were to tune to an AFV of 100 at 5000 feet, and did a great job of the whole map with it set there, the bike would run just fine (per what mike wrote). But the bike would be non-standard. That is, if you operated it at sea level, the AFV would be much higher than 100. It would run fine if it was consistent, but the AFV would scare a sea level tech that hooked up to the bike and read the AFV. Al | ||
| Dynosaur |
You should always tune the CLL with the sensor you are going to use to control with, i.e. a NB. A WB and a NB aren't necessarily going to "agree" at lambda 1 ("assumed" to be 14.7:1 with pump gas). | ||
| Xoptimizedrsx |
what Al posted finishes the theory on how to do it. Its all balance to your bike your area. no matter what and how you must balance the O2 to the afv. If not you can have very low numbers but actually be fine or crazy high numbers on the afv and still be fine. the issue is tecs look at charts and could think you have an issue when your bike is spot on. example. my street bike its set to run a afv at 99/101 most of the time its 100. my race bike its set to run a 130/135 afv (on purpose) so if you put my map in your bike you see very low numbers in the map. (my max fuel value is 189 on that map. where standard xb12's have much higher values unless they are running a high afv as well with the setpoint moved on the O2). this is because the global afv will pull the overall table up to make it run at the 13.2 afr it set to regardless the afv. my map number + avf= 13.2 afr now if you have a cylinder (rear) and the afv is at 95 at one rpm then 100 at the next up then back down again at the next even further up in rpm. you have unbalanced afv/afr. you need to adjust the fuel zone till you know the afv is stable at that area. this must be done across the board. the cl must be set to the setpoint of the O2 midpoint setting as afr setpoint. go to rich it will lower the afv go to lean it will raise it. no Now OL it will learn in open loop unless turned off. dont let it fool you. if on you are stuck at the stioch values. if off its fair game to set it to your afr of choice. but make sure if the front cylinder afr is at one setting match it to the rear to be the same. thats adjusting in a nut shell. | ||
| Xoptimizedrsx |
to go on what Al stated on AFV about scaring people. back when I did tunes for people the ones i did would remember a working afv from you bike was needed. This is and was so I could scale the setting to read as if I was on your bike in your area. without knowing the afv and the map from the bike it was on you are clueless as to what direction to go. knowing the afv at each rpm zone tells you exactly what the bike is doing. as well as what it is asking for. do this guys. look at the rpm table make a list on what rpms you have. now go ride one zone and pull over read the afv. write it down then do aprox 8 miles steady at the next rpm zone centered. drop gears if you have to to keep speed down. write it down again. keep up the process till you have covered the cl area. once done either add to the area it was lower or remove from the high. balance the afv's thats all you need to do at first to complete the zone. later you will refine the map to open loop power based on afr. which you can use OL learn on to do this as well knowing how much more to add to set the afr. if you have no o2 and no temp correction . well thats a new topic... very messy over time... be ready to buy parts. | ||
| Brightbuell |
What parts will i need to buy cuz my 02 is boxed in? just a question noting to read into. | ||
| Speedfreaks101 |
Good thread.  | ||
| Brightbuell |
Ok, I just changed to 99 low 101 high and it is running great. Even better! Im happy with it. Im not changing it anymore, its runnuing perfect. Tons more power. Im done with tunning threads! WOO! HOO! (Message edited by brightbuell on August 27, 2010) | ||
| Pash |
Arrr (as we say in the Kingdom of Wessex) but AFV is only applied to OL and it is the EGO (an instantaneous correction) that is applied in CL and CLL (and CL Idle) and that when in CLL for sufficiently long enough AFV = EGO. So, if you unplugged your O2 sensor and pushed the AFV up to 110% for example, you would not be applying 110% to what was, but what can no longer be, the CL and CLL area. We need to adjust the CL and CLL areas cos the further the map is away from the target (lambda = 1), the more eratic the control due to overshoots etc. The stock CL and CLL areas are fine for the stock headers, but once you change to a Free Spirits, a Ti Force or a Micron (to name but a few), the peaks in volumetric efficiency move and hence the peaks in the fuel maps need to move too... Hi Mike  | ||
| Xoptimizedrsx |
Hi Pash!!! some will get it some will not... this has been a ongoing issue where the target afr is just as you stated. match it up allow it to work with the O2 and all is wonderful. go back woods tuning on it a its a mess. as we all know dyno sheets of paper always doesnt mean its going to preform well on the road. That has been proven many times over. any way between what Al wrote as well as yours and mine. if people dont get it from that they never will. Hi Al as well... Mike | ||
| G4string |
Mike, I dont know if your post was directed at me?? However, I am not trying to undermine anybody.....I am merely trying to wrap my head around the theory of how our ecm works. That is all. To all others, the same applies. Please dont take questions with any offense. Again, all I am trying to is FULLY understand the what's and why's of tuniing our ecm. (Message edited by g4string on August 28, 2010) | ||
| Xoptimizedrsx |
my post was not directed to anyone only to how things work. I speak(type) in general. hopefully with the more and more info accumulated over time the better and more aware people become and don't fall into traps on tuning. some place acclaim to be the best at doing ecms on the dyno. but they cant just bring a pre-made map to the a different location and be correct. It had to be custom tailored there on a different dyno. that's proof the maps are not accurate Every where just because it was correct at one location. this is something any decent dyno operator can do. reguardless the dyno map and the true road work map will not be the same. map it on the road if you ride it on the road to be best for the road. map it on the dyno if you ride it on the dyno. Their is a difference in the two. dyno maps get you in the ball park. But, only if its done on the bike within reason or altitude,fuel composition,and ect. example 1 my sea level made maps ran like crap in my bike at 5000 ft on different fuel brand.had to datalog to adjust, tunerpro Rt. ex 2, my race map in exactly the same built bikes ran bad in another race bike. where mine ran fine. ex 3 a well known very good exhaust company I do many of there maps for free. i made a bike identical to there's made the map. they tested it and was bad. I hooked the logger to the bike did one reading and a slight adjustment and it was good again. rechecked my bike with the same map at the same location same logger. my map was great no changes needed. two alike bikes same parts and ect two different maps are required. | ||
| Paint_shaker |
I think my carb needs to be re-jetted... LMAO | ||
| Vospertw |
All, I'm sure I'll catch some grief for this post, but I'm not trying to say anything discouraging about anyone or our bikes. Before I start, let me say that there are guys in this thread who have forgotten 5x as much about engine tuning as I know. I've had 8 bikes in the last 7 years. Half carb'd, half FI, everything from 650 thumpers to 1100cc I4's, Yamaha, Suzuki, Kawasaki, BMW, and now the Buell. Like most of you, I'm a motorcycle nut, so if someone says "wanna ride this?" I'm on it like a hobo on a ham sandwich - so I've ridden quite a few models in the past few years. I ride consistently 1000 miles a month. I don't state any of that to impress anyone - I know there are many of you who ride better, faster, more, etc. - only so you can see where I'm coming from. I'm not a brand loyal guy. I buy the bike I think will work for the riding I want to accomplish. I bought my Ss because the longer suspension seemed to be a good thing for our less than smooth back roads, the ergos were comfortable, the extra gas was a bonus, and the bike was fun as hell. Also... maintenance is minimal. Although I actually enjoy taking care of my bikes, I don't have much time right now between job and family and "minimal" maintenance is a good thing. As I read this thread, it sounds like I NEED to be doing some level of tuning just to get the bike operating properly for me. That might be a bit of a chore according to what I'm reading here, since I normally ride from SL to 6K' and back every weekend. As I read Xopti's post on 26 Aug (third one up from here) about reading and writing the AFV values while out riding, that would literally take me more time than I've spent on fueling/fueling issues with all 8 of my previous bikes combined. If that's really what has to be done to have a properly operating Buell, then I'm worried I bought the wrong bike. Again, sounds interesting and kind of fun, but I can either do that with my riding time... or ride. I choose to ride, and the bottom line is that I could buy any number of bikes that would do what I need to do, and that would require no FI tweaking at all for my riding. Heck, my 11 yr old GS runs fine at all altitudes, all year long, and has 65K miles on it. Now, all of that being said, as I mentioned in my earlier post, I haven't noticed anything adverse about my bike's performance except for some off-idle roughness (and suspect a breather reroute will likely fix that) which is another reason I'd rather go riding without worrying about AFV's and tuning maps - I've got no complaints with my current map. Am I misreading this thread? | ||
| U4euh |
Nope! I think the original poster just wanted to know why others are tuning their bikes. Most will tune because of some other modifications done to their machines. They do it to get a little extra out of it or to make it better with the mods they have done. If your bike is running great, like you say, go out and enjoy it and worry about any of the above. |
