| Author | Message | ||
     Marcodesade |
Can someone help deepen my understanding of AFV's please? My bike is an 08 R (Cali), denoided, with airbox off. I had values of 87.5 in the front and 100.0 in the rear. After my most recent service, which included upgrade to k&n filter, the bike came back at 100.0 in both, though the tech claimed not to have had to touch the AFV's. Now though, 2 weeks later, they are back to 85.5 front (!) and 100.0 rear. I guess I have a few questions: *I understand the target is about 95-105 for both. Why (that is, why are higher or lower values bad)? *What would/could cause my values to jump so radically in just 2 weeks? *Is there something I can do to adjust them myself when necessary? Is that advisable for a n00b? *What's this everyone is saying about locking them? *Am I in for more headaches when my Jardine exhaust and Pro-Tune3 card arrive in the next week or two? Thanks for the help! | ||
| Bob_thompson |
+1 Marco, I also asked about this in another thread. Guys? | ||
| Daggar |
Higher means fuel is being added. Lower means fuel is being taken away. If the AFV is too high or too low, it could indicate that there is a problem somewhere. I'm not a mechanic or anything, so hopefully someone smarter will chime in. AFVs can be locked with tuning software. You should tune for your exhaust for maximum benefit. | ||
| Unibear12r |
I think the AFVs will reset with just disconnecting the battery even if the Digital Tech was not hooked up to your bike. I haven't tried it so I don't know for a fact. Might be what the tech did while working on something else. I've seen five point changes in the AFV in a half an hour of riding. I suspect the ECM can make far larger changes in far shorter times. Unless you are getting a trouble code for your AFVs I wouldn't be too worried at what they are doing. Be watchful, but not worried as long as your bike is running good. I don't think you'll get any trouble codes until one (or the other) AFVs drop to 80 or you get more than a 20 point difference between the front and rear. That's what it appears to have been when it happened to me before. No ill effects and the bike was running great. I suspect (but have no proof) that the Cali bikes get extra fuel to the front intake from the evap system when the temps are up. So the ECM is compensating for it and dropping the front fuel rate like it should. And you are not waisting the fuel that the 49ers are out the vent tube. It's just that it seems that this effect can push the AFVs past the set points set for a CEL/trouble code. If you do get a CEL for this it will be when it's very warm weather, the bike is quite warm, and you are stuck where you have to ride 25 mph or less for an extended time. In my case I'd say the ECM has a far better idea of what its doing than I do so I wouldn't be locking mine. Headaches with a Pro-Tune are quite possible if you don't know what you are doing. | ||
| Ponti1 |
Getting the latest flash automatically resets AFV to 100/100, with the intention of forcing the bike to learn "from scratch" on the new calibration. | ||
| Fresnobuell |
In my case I'd say the ECM has a far better idea of what its doing than I do so I wouldn't be locking mine. True but remember the EPA and CARB are restrictive of what the ECM can do regarding fueling. I can tell you for a fact that the stumbling/hesitation (primarily off the line) }came right back this weekend when my AFVs were set back to 100% and allowed again to adjust themselves. (Message edited by fresnobuell on June 08, 2009) | ||
| Marcodesade |
I always hate it when someone adds some BS to a thread just to keep it in rotation near the top. However, that is exactly what I'm doing, because I'd really like some more information on this. This has all been really interesting stuff so far, but I'm really looking for the kind of info that might actually get me started adjusting things. Can someone help? Thanks! | ||
| Dirty_john |
I thought the AFVs were updated to suit conditions, i.e a change in altitude, if this is so then an identical set up at sea level would show a different set of AFVs when ridden in a mountain area I suppose. As someone else has stated if the values suddenly change and all other variables are more or less the same does this indicate an abnormal condition? | ||
| Spectrum |
Take this with a grain of salt as I have no real expertise here. But I can't see any beneficial purpose for the AFV's as far as dynamic engine tuning goes. There is an air intake sensor and baro sensor to adjust for variations in atmospheric conditions. The baro sensor would adjust for air density and altitude changes. While the air intake sensor would adjust for air temperature changes. These sensors seem to do a good job of keeping the bike running good in changing conditions. So what exactly do the AFV's adjust for? We know the AFV's are adjusted in closed loop using input from the O2 sensors. I can't see a need for them other than emissions control. My none scientific experience shows that if you disable closed loop and lock the AFV's, the bike runs better and does just fine. | ||
| Fresnobuell |
I agree Spectrum. I only hate that I am shooting in the dark as far as where to set the AFV. Also, you can't set the front value different from the rear. AFVs increase fuel across the whole range and that can't be totally correct (can you say tuning?) Obviously running rich has its own consequences and wastes fuel. | ||
| Spectrum |
I only hate that I am shooting in the dark as far as where to set the AFV. Oh? seems to me 100% is where the factory engineers thought the tune should be. Easy for me to say though. I had mine put on a dyno and the AF ratio was spot on at 102/97. | ||
| Fresnobuell |
Are they locked at 102/97? If so, how did you lock them at different values? | ||
| Socoken |
Oh? seems to me 100% is where the factory engineers thought the tune should be. To meet EPA requirements, not to make the most power or run the smoothest. What is spot on AFR? From everything I have read these engines like to be in the low 13/high 12 to one for max power. I just ran mine on the dyno and where it went above 14 to one, the power dipped. | ||
| Fresnobuell |
So dyno tuning revolves around analyzing the AFR and targeting the 12:1 or 13:1 ratio? Most dyno runs are wide open in 5th gear? If so, how are partial throttle openings handled in the tuning process? Obviously, we aren't WFO all the time. | ||
| Ponti1 |
Isn't that why wideband and more extensive data logging is preferred (over dyno only) to get a full tune across all RPM and throttle positions? | ||
| Hellgate |
Depends on the type of dyno being used. For an inertia dyno, yes, WFO, and it doesn't really tell you too much. If an Eddy Current is used you can hold the bike at a given rpm. As far as AFRs, they really don't matter and they are a dynamic reading, not a static one. Instead of a lambda probe a 4 Gas EGA is a much better tool to analyze the exhaust out put. The 4 Gas EGA provides a look into the combustion process by giving CO, O2, CO2 and HC percentages. The idea is to look for and tune to complete combustion at a set of RPM, and throttle positions. With the new PC5 you can now create a map for each gear. | ||
| Socoken |
Obviously, we aren't WFO all the time. While this is true, we only really care about peak hp at WOT. As long as you set your AFV at a setting that allows a smooth running engine for most riding, and have boosted fuel tables for 100 percent tps to allow for peak hp, that should work, right? In other words, if you lock the AFV at a setting that works great most of the time, and tune for 13:1 on the dyno, wouldnt that be acceptable? | ||
| T_man |
Perhaps this has been answered elsewhere - but as per Fresnobuell's earlier post here- Can WE lock the AFR's WITHOUT external tuning aids? Can we do it through the bikes cluster? It seems to me the bulk of 'fixing' the 1125R's fueling issues can be resolved with global enrichening. Perhaps the 'forbidden' tools are necessary to do this - but I have a sneaky suspicion that in general all this bike wants is more fuel... Comments? | ||
| Ponti1 |
T_man, AFV can't be manipulated via cluster or other built-in method. Further, other tools are needed to disable the closed loop operation, which if not done will just overwrite whatever AFV manipulation is done. Does that help? | ||
| T_man |
Thanks Ponti1 - that does help. So much for my hope of a simple way to richen up the system! Looks like I'll have to turn my attention to 'other tools' to get this bike sorted. | ||
| Xelerator |
"...with airbox off. I had values of 87.5 in the front and 100.0 in the rear." Is this difference in A/F values proof for a negative influence of taking the airbox cover off? Airflow, mass distribution? |
