| Author | Message | ||
     Bobup  |
ok..the question is because of my local dealer saying that adding a K&N filter alone would void warranty because it would lean out the mixture and possibly cause burnt pistons... so here is my ? wouldn't the ECM (stock ECM) adjust for the higher air flow and adjust accordingly? it would be just like going into higher elevations where the air is lean and backs down the fuel, the programed ratio is what the ECM tries to maintain i would think... more of a curiosity than technical question since i will be adding a TFI unit at the same time thanks bob | ||
| Cataract2 |
To an extent, the EPA limits on the stock one kinda hurt how much it can adjust. Just get the race ECM and race pipe (or some other after market one.) and let the smiles shine. | ||
| Wyckedflesh  |
I would find a new dealer. The K&N by itself is not sufficient to cause the lean condition your dealer is claiming. (Message edited by wyckedflesh on February 11, 2005) | ||
| Tank_bueller  |
I just slapped a 12 lid and K&N on my 03' 9S last weekend and have put about 100 miles on it.(no techlusion yet, and stock pipe) So far, so good, and the old "butt dyno" gives a  . Sounds better too! tank | ||
| M1combat  |
Find a new dealer... Assholes. I ran a K&N, Cut airbox, no snorkel for about 10K miles with no problems. AND I live in the mountains... | ||
| Wheelsleaning  |
I was told (BY MY DEALER  ) to keep all the factory parts on hand in case of a warranty issue. | ||
| Blake |
Bob, What the fine BadWeBrs above said! To clarify one tech point in your post though... When going up in altitude into ever thinner air, the mixture would tend to become richer, not leaner (less air, same fuel equals richer mixture).  | ||
| Opto |
Bobup, another direction is to fit the K&N with the dealers permission with the condition that you go out and do a few miles to let the ecm settle in and then bring the bike straight back into the dealer to have an AFV (adaptive fuel value) check. Then the dealer will know if the bike's running lean or not. This may satisfy him. This is what I did with my XB12 a year ago and dealer was happy with that. | ||
| Blake |
How would the dealer diagnose if the bike is running lean or not by inspecting the AFV?  | ||
| Keith  |
If the dealer has a dyno, he may the ability to check the air/fuel ratio. That is how you can confirm rich/lean condition across the rpm range of the engine. | ||
| Opto |
Blake, I'm not sure exactly how it all works but from what I was told by the service dept manager who was actually checking my bike, if the AFV is sitting around 100% then everything is OK. When I was having driveability and pinging problems with the race ecm the same manager checked the AFV and told me it was at 88% and the ecm couldn't lean out anymore, and that my bike was running too rich. Then I refitted the stock ecm and had the AFV checked at 100% (with Drummer pipe) which satisfied his fears of my bike running too lean. | ||
| Opto |
IOW, I believe that the AFV reflects the deviation in percent of delivered fuel from a factory defined ideal baseline. | ||
| Bobup |
Ok...so this has been quite informative. Blake....i would still believe that going higher in elevation will result in the ECM adjusting (decreasing) the amount of fuel in order to NOT have a richer mixture. thus you will get better mileage at higher altitudes. I have experienced this in my '93 Cherokee while in the Sierras. This is also why EFI is better at high altitude than 'old carburation'...no more flooding due to a richer mixture. | ||
| M1combat |
But it won't lean out the mix. It'll reduce fuel as physics reduces air. | ||
| Blake |
Opto, A race ECM was running too rich. Okay, I'm with you. It was pinging? Lost me there. Pinging won't likely occur with a too rich mixture, only a too lean one. The AFV value tells you almost nothing concerning mixture. It might help with a semi-educated guess, nothing more, but there are too many variables. Bobup, I agree, the ECM will reduce fuel as you climb in altitude to keep the mixture from becoming too rich. One other tech clarification: A vehicle will achieve significantly improved fuel efficiency at higher altitudes more from the lower drag of the thinner air than anything, but yes, maintaining proper mixture (A/F ratio) also helps improve fuel efficiency. My '97 Cyclone's stock CV carburetor does a decent job of self-adjusting mixture with altitude changes. You might be surprised at how well it does. Certainly not as good as your DDFI though. | ||
| Craigster |
Check page 120 in the March Cycle World for the answer to the power vs. altitude vs. speed question. I know many would not believe my post so I'll refer those to another's published thoughts. | ||
| Opto |
Blake, I stated above what I was told, not what was actually happening. I was having probs with the race ecm, and the manager thought that because the AFV was at 88% and therefore the ecm couldn't lean out any more that the bike must be running rich causing the drivability probs. What was really happening was that it was running lean which I confirmed after fitting an O2 sensor monitor. The AFV value tells you almost nothing concerning mixture What I read from what he said indicates to me that the AFV has a lot to do with the amount of fuel delivered, but I guess that depends on personal interpretation. This guy is one of the highest-trained Buell techs in Oz. They gave me a couple of free tps resets to try to rectify the problems but little else could be done at the time because I was running a non-Buell pipe of unknown quantity and the race ecm was bought from o'seas, so warranty was understandably out of the question. | ||
| Rr_eater  |
Forgive me, but may I chime in here, for a second.... HOW does the DDFI know when you are going up in altitude? My understanding, which is above the average on automotive fuel injection application, that in order for the vehicle to TRUELY know it is increasing in altitude, a sensor registering barometric presure is required, IE a MAP sensor. NOW, forgive me if I am wrong, but in my thumbing through the manual, I did not notice or find any reference to a MAP sensor, but I do not have the book right here in front of me now, so I may be talking from my behind. So, if I am correct (maybe) then the only way for the system to know that it is increasing in altitude, would be by seeing the mixture richen over time, and try to lean it out accordingly. BUT, this does not tell the ECM it is actually increasing in altitude, just assumes based on mixture, and there are TONS of reasons for the mixture to go lean or rich besides altitude. Just babbling now, but please enlighten me if I am WAY OFF line here guys Bruce | ||
| Craigster |
You got it RR, It's Alpha-N with a closed loop map section. | ||
| Blake |
You are right, the DDFI doesn't know anything about altitude or barometric pressure. It adjusts for its effects on mixture through sensing mixture directly via the O2 sensor. The DDFI adjusts directly for what the EFI must be directly concerned about, the state of the mixture. Ambient pressure is immaterial to Buell's DDFI. |
