Ecmspy question: disabling O2 sensor

[OldGeezer]

Hey snrusnak,

I was poking around the web and found this at: http://www.steveturnbull.co.uk/buell/buelltuningguidev1.4.doc

Here is an excerpt:

"Understanding the AFV
The Adaptive Fuel Value is how the Buell automatically compensates for changes to the environment, eg riding up mountains, or swapping the exhaust silencer. It is not perfect, but does a good job to compensate for minor changes.

When the bike is ridden in Closed Loop mode (explained next) the ECM monitors the O2 sensor and learns the appropriate AFV value to apply to the fuel maps. This AFV value is applied across the entire fuel map range, hence it is critical that this is accurate. AFV values can vary from 80 to 160% but should be kept between 90 and 110% whenever possible.

The AFV can be your friend, fine tuning the bike to suit your location, or it can be your worst enemy! If you setup the bike on the dyno for maximum power across the range, you will probably aim for 13:1 – 13.5:1 Air :Fuel ratio. If you then go for a ride and enter closed loop mode, the ECM will reset the AFV to maybe 80% to reduce fuel and try to get the default 14.7% AFR. When you next accelerate hard at full throttle, your perfect map as setup on the dyno will now be running at 80% of your values hence weak!

To compensate for this, it is recommended when on the dyno to disconnect the O2 sensor, reset the AFV to 100%, then tune the bike for an Air Fuel Ratio of 14.7% within the closed loop area. This will then allow you to set the Air Fuel Ratio for optimum power in the high rpm, throttle areas. 

Always reconnect the O2 sensor after tuning and check the AFV periodically."

Hope it helps

 

[snrusnak]

Thanks oldgeezer. I haven't had a chance to do anything with it right now, been busy. Today I worked about 14 hours (ugh) and just got home. Tomorrow and wednesday night will be busy as well, then going on a cruise with the wife for our 1 year anniversary. Maybe I will be able to do some more reading on this while on the ship

 

[FlaXB9R]

Sean if your reading about your bike while your on your cruise your wife is probaly going to slap you and I don't even know her but you will deserve it . Enjoy yourself and worry about the bike when you get back . I think it would be safe to say your bike is going to be the last thing on your mind anyways there's just to much to do on the ship and off when at port . Have fun and happy anniversary

 

[snrusnak]

Curtis, you're probably right lol! I've never been on a cruise so don't really know what to expect...we are going to the bahamas; 1 year down, many more to go

 

[FlaXB9R]

Bars/clubs , casino , pools , shows etc... The comedy shows are usually pretty good or I've been a few sheets to the wind every time that I just found them entertaining . Captians night I think its called is a must attend (free drinks for atleast an hour) also you need formal waer this night and may have other formal nights for dinnig too . And I cant forget to mention free food all the food you can imagaine . The bahamas are nice but I would recommend doing an excursion I personally didnt find it to nice around the island and seemed easy to get lost . My last cruise was in the bahamas and I rented scooters because the wife and I enjoyed it so much in cozumel but not so great there. JMO . Also they will give you an itinerary evryday check it out to find out was going on they have alot off cool stuff going on all the time that you wont even know about if you dont check that out .
Thats just a little of info . Have any questions just shoot me an email .

 

[snrusnak]

Thanks man!

 

[Morbid]

Dude you ever get this sorted out? Or did you decide to stay in the tropics

 

[snrusnak]

LOL we did return from the cruise! I actually have not ridden the bike since though. I put some fuel stabilizer in the tank this past weekend and rode it about 15 minutes, then ripped the whole front of the bike apart to get parts powder coated, rebuild forks, new brakes, and fix some broken parts. After it gets reassembled I'll be focusing on this again. Probably a month or so out.

 

[mmcn49]

Hi Snrusak,

I’ve been playing with the maps and doing a bunch of things over several years. Finally a while back I got the bike running the way I want it. I’ve figured out several things on my own, plus I’ve had input from several folks on the three forums including Xopti. Here is what worked for me:

Replaced the throttle body seals with Genuine James seals.
Removed the exhaust valve actuator.
Wired the exhaust valve open.
Replaced the air filter with a free flowing UNI filter.

In the 3D view of ECMSpy I smoothed the fuel maps, eliminating the mid range dip. Also along the top of the map I eliminated all the high spikes. GB suggested adding 3% to the center portion of the rear map and 14% to the front after smoothing. I tried that and found it not necessary. You may have to play with this a bit to dial it in.

To stop decel popping I changed cell values on the right side along the bottom two rows. Along the bottom row, when the cell value dropped below 25, I changed the value of those cells to 25. On the next row, when the cell value dropped below 28, I changed all those cells to 28. These values eliminated all the popping plus it did not effect engine braking. Do this on the front and rear maps.

NOTE: I’ve tried all kinds of race maps including custom maps that forum members e-mailed me. What I ended up with is a smoothed variation of one of the custom maps plus the decel changes. I also tried datalogging with MLV but only had fair results.

I tried a half dozen timing maps and ended up using the stock timing maps with this variation. Bottom two rows, three columns on the left I put in 7 on the rear map and 9 of the front. Now when I blip the throttle the engine picks right up.

I also run a WB o2 sensor and LC-1 controller. The air fuel ratio in the LC-1 is programmed for an AFR of 14.55:1. If you leave the NB o2 in you can trick the ECM a little by changing the NB mid point in ECMSpy to .52. It’s probably at .49 now. This will make ir run a little richer.

In the other maps page set the Open Loop Enrichment to 108 for an XB9 and 113 for an XB12. Set the second from 3 to 0.

The Red Box in the fuel maps is Closed Loop Learn. You need to shrink the size of the Red box. I’m not at my home computer so I can’t give the values of what I’ve done but you want to shrink its area by 40-50%.

If you click on the red line while dragging the mouse over it and small boxes will show up on the line. Click on the box and blue arrows show up at the bottom of the page. Click these arrows to move the little boxes to shrink it.

With the change I made on my two TT’s one is running with an AFV or 96 the other one is at 105.

I done a few other things but this should be enough to get you started.

 

[snrusnak]

Thanks for the info, when I get the bike back together I'll follow this advice!

 

[Morbid]

I think I am going to go the route we did on our 990 Superdukes and just turn the O2 sensor off.

Worked darn well on the superdukes and they came from factory with an O2 for each cylinder. We used them to find our tune then turned the darn things off so they would not try to correct our maps back to emmisions levels. It's not like I am planning on riding up Pikes Peak any time soon

The arguement over to turn off or leave on the O2 sensors on the superdukes went on for awhile but the majority of us found that turning them off left us with a much more predictable and better running engine overall.

 

[xpwarrior]

I've been making some mapping changes on my bike and was tempted to disable the O2 sensor also. My last bike was a Triumph Speed Triple and I had the O2 sensor on it disabled and it really helped it. The difference between the S3 and the Buell is that the S3 had a MAP sensor and the Buell does not. I didn't realize this until reading this thread but the lack of a MAP sensor may be a good reason to leave the O2 sensor active.

I've got free flowing exhaust and intake and have switched to the race map. Even with the race map the ECU has increased the AFV to 104.

 

[snrusnak]

Mine is doing the opposite and going lean... FYI there is a mod you can do to add a MAP sensor to the bike.

 

[xpwarrior]

With yours going lean I would defeinitely check for any air leaks or other problems and possibly swap out the O2 for a new one. When I first got my bike the previous owner had added the intake and exhaust but was still using the stock map. The ECU had increased the fuel to 117 and the bike ran OK. I switched to the race map and the bike didn't run as good until the ECU increased the AFV to 104 where it has stayed.

I noticed the mention of the MAP mod and will have to look that up but so far the stock O2 system is working good for me. I do think that the bike needs either a MAP or an O2 to consistently work right.

 

[snrusnak]

Yeah I may have leaking intake seals. After I get my front end all back together I'll be doing the seals and a few other things. That will be over the rest of the year most likely as I'm always short on time. My goal is by 2013 to have everything done and just be maintaining it.

 

[dsmithurst]

snrusnak,

Any updates?