| Author | Message | ||
     Only1beard |
Back in 06 and 07 there was some talk of running lean after changes to air box and exhaust. Would this be the case with the 08 and latter?? Link containing referenced info http://www.badweatherbikers.com/buell/messages/327 77/206506.html?1150442264 | ||
| Froggy |
Yep. I wouldn't alter the intake or exhaust unless you got a way to retune it, they run lean enough as it is from the factory. | ||
| Only1beard |
So you saying ECM for 09 does not learn at 3200-4500 RPM.??? I may be in trouble here.  | ||
| Froggy |
It does learn, and make adjustments to the AFV, but you still would be too lean. | ||
| Only1beard |
So now what? I got to get the ECM spy. I made my exhaust and while I was at it I took some of the innards and made a removable baffle. Guess I run that till latter then.  | ||
| Percyco |
Many on this board have said that it is completely safe to run a modified exhaust with no other alterations. Seems to be a few different opinions on this....you can probably do a search and read more on the subject. | ||
| Only1beard |
I was under the impression that the ECM would adapt to changes made. I have seen no lean running conditions riding. Sputtering, backfiring, or running hot. Looks good to me. I don't run very fast close to home but there is one rout I will do on average 80mph and stop at a truck stop to check vitals. Never any problems except the exhaust strap. | ||
| Percyco |
My dealer told me that the ecm could correct up to 10%. And that there wouldnt be a problem just adding a exhaust such as Spec ops. Theres plenty of real nerds on here that know alot about this..... | ||
| Spdrxb |
MY .02 is this..... In stock form (08 XB12S) seemed to be running very rich when new. I would always end up with carbon spatter on my left leg when stopping at stop lights etc..Pipe outlet was covered in a lot of carbon residue ,fuel mileage was 42-44ish mpg. Last summer I put on the Voodoo exhaust. Gained fuel mileage now (46-48ish) no running issues, no more carbon splatter and cooling fan seemed to run less than it did before. In my case I think it did make it leaner but it helped out an already too rich condition. Every bike is probably a little different hope that helps a little. (Message edited by spdrxb on January 14, 2010) (Message edited by spdrxb on January 14, 2010) | ||
| Chainsaw |
Back in 06 and 07 there was some talk of running lean after changes to air box and exhaust I ran a race filter and a Special OPS pipe on my 2003 for a year on the stock ECM with no detectable ill effects. The spark plugs came out looking perfectly normal, no indication of running lean. YMMV, but I really don't think it's a problem. | ||
| Only1beard |
YMMV ? This has been a good topic. Lots of different opinions. As long as I dont change the displacement the It should be able to handle it. As long as the CO2 and MAP is in place and ECM learning It will always adjust the fuel map accordingly. mb | ||
| Chainsaw |
YMMV Your Mileage May Vary | ||
| Gunut75 |
When I had a stock pipe on my 12R, I got a little popping on decel. It actually sounded the same as with the Hawk pipe, just muffled. So I know the bike did not develop a lean condition from the pipe. After installing the pipe, 600mi. so far, and the spark plugs look great. I guess I'll find out for real when I get the bike dynoed. | ||
| Nik |
The ECM can only adjust the entire map by some multiplier, not each individual cell. So yes it 'learns', but that might mean it richens up the whole map so its decent at the learning cruising rpms, super rich at idle, and lean up top. | ||
| Froggy |
Bingo. A retune is highly recommended, even with the stock pipe.
Good luck finding a MAP sensor on the XB. They have a narrow band O2 sensor, AIT, ETS, speedo, tach, CPS, TPS, and BAS. No MAP, MAF, or any other sensors that many other fuel injected vehicles have. | ||
| Boney95 |
Go ahead and run the bike with the exhaust and filter. I've been doing so for the past 6k,and I'm fine. That being said, I'm going to buy the race ecm when it becomes available. | ||
| Only1beard |
I was under the impression that the sensor mounted in the bottom of the air box it a temp sensor ( Manifold Air Pressure/ Temp ) MAP ???? The rear head has a temp sensor and the the exhaust has a CO2 sensor. These sensors working together create a closed loop allowing the ECM to learn. The ECM Will learn! The question is now how much. ? | ||
| Nik |
There is an air inlet temp (AIT) sensor in the airbox, it is not a MAP sensor! The temp sensor in the rear head is just for startup enrichment (ie. the choke.) The sensor in the exhaust measures O2, not CO2 (otherwise Al Gore would collect that information to tax and guilt trip you.) Anyway, I said before how the ECM learns. There is a multiplier (AFV) that scales the entire map. It is meant to compensate for changes in density altitude only! Will you blow up your bike with just bolt ons and a stock ECM? Probably not. Will it learn an optimal tune? NO! | ||
| Only1beard |
Thanks Nik ... Now I got to get this bike tuned. Does 3 hours on a dino sound like too much? | ||
| Buelldyno_guy |
Wow, not too sure where to start and before Blake yells at me for this post I want to ask you all something! Can we lobby to have a stand alone board across all bike types just for All Things Fuel Injection / ECM, not a technical how to, but just discussions like this one? Back to the subject, Nik has got it sort of close, but here is what I have come to believe goes on. The system is not the Speed Density type, so no MAP sensor is used. On X1 thru XB's Buell designed and used what's called an Alpha-N system. Alpha-N control uses some serious math inside it's algyruthims. If you can ever get chance to see inside one of Henry Duga's old Kimble DOS For Race Use Only ECM's you can start to see how such a system works. But back to the street model. When first started and cold, the ECM simply adds warm up fuel via a fuel table, which can be modified. The Feds want everything out of an un-controled warm up mode ASAP, so as soon as the (non heated) single wire 02 sensor comes up to temp it goes into "closed loop idle." This is where the math starts inside the ECM and where 02 sensor voltage starts to tell the ECM the A/F ratio. A narrow band only sees 14.7 which is still way to lean for a cold engine. The ECM uses the 02 sensor voltage, then by looking at what I like to call a look-up tables (fuel / timing) to see the value in the active (RPM/TPS) cells it continues to skew those table value as the cylinder head comes up to temp using the warm-up table. At full operating temp the same process us used with the ECM fuel map having three different areas. The first being "Closed Loop" the AFR in those areas of RPM/TPS map controlled to 14.7, which by the way just happens to be 100% AFV. Inside the CL area lives cells called "Closed Loop Learn" and is where even more serious math takes place. In learn mode the system continues to controll to 14.7, but also remembers the 02 voltage on both the lean and rich sides. It is during those lean / rich swings it learns as it adds or takes away fuel to get the controll to even out. But it does this across the entire map and we see it as a new AFV. (Note) a rich AFV can cause the ECM to remove enough fuel to cause a lean miss-fire on the uncontrolled front cylinder. This is getting way too long, but the last thing to remember is the third section of the map, "Open Loop." this where the WOT lives and where the serious HP is made. Defined by both RPM/TPS using the fuel/timing look-up tables offset by inlet and cylinder head temp sensors. While the 02 sensor does not controll this area there are safe guards built into the ECM limits that will bump the AFV up to the max if it sees a very, very, very lean condition. From experence can tell you it won't run well and can even foul plugs like that. Sorry about how long this was and the spelling (I can't sleep and used my iPhone to write it.) But In hope it helps someone Terry - www.jtsperformance.com } |
