| Author | Message | ||
     Al_lighton |
We finally got Directlink able to talk to 07 XB12 ECMs (not released yet, soon), and as a result, I've been able to get a peek into the differences between the 06 and 07 fuel and spark maps. I won't post the entire tables here, they are Buell proprietary stuff. But I can describe the general differences. As expected, the AFV learn mode values were richened just a little to match the extra air that comes in. If they hadn't made that change, the fueling in the map would have been a little lean, which would have the effect of driving the AFV up. But other than a little bit of leaning in the upper reaches of the WOT front cylinder map, the majority of the fuel map is unchanged. And the differences aren't very big to begin with. None of the changes I saw would drive the AFV more than about 5 points, and mostly much less. The Spark map was also largely unchanged, but they did pull a little bit of advance out of the high throttle, high RPM part of the table. Not a lot, mostly between 1-3 degrees max. This is not to say that they didn't make other changes that aren't shown in the fueling and spark tables. Remember, we can't read or see the algorithms that use those tables, we can only see the tables themselves. For instance, they could have thrown a constant scalar in there that scales the entire map slightly richer or leaner, and we would not be able to see it. So we don't really absolutely know more than before. But given what the physical changes were on the airbox, I'd bet that the changes were primarily in the tables. Al | ||
| Hogs |
Thanks Al, Good info, guess they wd. have ha to add fuel for the increased in air flow, Anyways any news yet on the 1450 kits getting Dialed in yet,or if ya don`t know your self who may I ask? | ||
| Scooter808484 |
So if all the changes are in the tables, as you suspect, that would mean there's no significant advantage in reflashing the ECM when putting the '07 airbox on an '06. The AFV should be able to compensate, right? | ||
| Diablobrian |
scooter, subtle changes can have large impacts on rideability and performance. There is a measure of artistry involved in building maps for injection and spark. | ||
| Davo |
It would be cool if someone could figure out how to shift the timing map off of the fueling map. Then moving the CPS would not effect the fuel timing if we could figure out how to create a phase shift variable (Message edited by davo on January 03, 2007) | ||
| Thespive |
Interesting info Al, but what does it all mean? I am with Scooter, curious about what your thoughts are for those of us with '06 bikes that have '07 airboxes and K&Ns, with everything else stock. Can the stock ECU compensate, should we get the '07 map loaded, or will you have a better map for our bikes? --Sean | ||
| Scooter808484 |
scooter, subtle changes can have large impacts on rideability and performance I'm not sure I agree with that. I've spent way too much time building maps for my HD via the Race Tuner (Wideband O2 sensor for feedback.) There's a really big range of AFR values where the thing will burn just fine, particularly in the cruise range which is where the Buell does its learning, and where Al says the changes were made. About the only thing you'll notice is changes in fuel mileage or maybe some low speed surging. Subtle changes can be very important at WOT, but those ares of the map are apparently unchanged from '06 to '07. The changes that Buell made, sound as though they were only intended to make the map "correct", and because it is correct, the AFV will be 100 at "design" conditions, instead of 105. That keeps thing centered and problems won't arise under vastly different conditions like high altitude. Just my guess!! | ||
| Lenb |
What's the effect of the 07 airbox on performance with the race ecm? | ||
| Al_lighton |
Correction: The front cylinder on the 07 map was richened in the WOT upper RPM part of the table. I wrote earlier that it was leaned, my bad due to the way I interpreted sign convention in my comparison spreadsheet. There was a fair amount of fuel added in the 4000 and 5000 RPM rows at WOT on the front cylinder, much less so in the other rows, and no changes in the other TP columns. The rear cylinder didn't get the same WOT fuel additions. The changes down in the low end were similar on both cylinders. No other changes were made elsewhere, the fuel maps are identical otherwise. What does it all mean? I think Scooter nailed it, they were just making the map more correct for the current physical configuration. The new air box would appear to flow more air, and it is better to compensate via the map than to let the AFV do it. It is possible that the AFV going up could have compromised EPA compliance since it scales the overall injector durations richer. There are likely legal requirements for Buell to submit data that shows it is burning correctly when they make physical configuration changes, but I can't say I'm familiar with those legal requirements. I'd have to guess that the extra fuel added up top on the front, plus the backed off timing, was to reduce potential detonation issues there, since that is out of the EPA compliance test areas. In looking at the previous years stock maps in those same locations, the front cylinder had generally leaner values than the rear cylinder in those same cells. The new changes make the front much closer to the rear, and a bit richer instead of leaner. Hard to say exactly why, but I'm sure they do it the same way we do, they run it, measure it, and adjust it until it has the right mixture. It does seem a bit odd that the rear wouldn't have needed more fuel if the new airbox configuration flows more air. But it can't be flowing that much more at WOT, otherwise they would have had to change the fueling on both cylinders, and in the other columns (i.e. 68% and 48% throttle) and they would be claiming a higher HP rating on the engine. I'm surprised the changes weren't more widespread, given the amount of openings added to the box. All 100% conjecture and guesses on my part. I don't have any more info than anyone else, other than the map visibility. Al | ||
| Impulsespcg |
Hi - First post - though I've been reading most of all you good folks' comments for a few months since I bought a New 05 12SCG in Sept06. I axed the airbox after 2 mos. and the MPG went down from 55 to 42. I have no other mods (yet) Might the 07 ECU flash help restore MPG, etc for the 05? | ||
| Thespive |
I had the Race ECM with the '07 air box and stock pipe and I didn't like it, so I took the Race ECM out and returned the stock ECM. --Sean | ||
| Raceautobody |
Gerald, Your MPG change might be caused because the longer you own a Buell the harder you ride it. Also when you moded the air box you are now getting a cool sounding intake honk so you maybe just twisting the right grip more. Just a thought. Al | ||
| Diablobrian |
Also when you supply more air (open air box) the ECM compensates by adding more fuel. |
