that's what i was getting at. Smooth...

 

Is it optimal? Probably couldn't answer that question without a dyno. Is it good enough? IDK. Would it hurt to try it? Assuming calibrate VE's, probably not? Does it look better than stock, maybe.

If you bought your PV through FM, I might give Jamie a call and tell him what you are trying to do (calibrate VE's, run a tune that's primarily - if not completely - open loop so you can try run an AFR table that's been enriched/more optimized etc.) and see what he says.

Edit: I didn't have to wonder too much about my tune (the TT enabled tune). It was created by FM (AFAIK on a dyno for a stock 1200). Perusing through it, it looked reasonable at the time (still does). I've been running it for the last year and the bike has been running pretty darn good. Seems to satisfy the "good enough" requirement.

If it was a tune of unknown origin or something just cobbled together by someone, then I might wonder some.

If I knew a really good dyno tuner within reasonable distance of me, would I go have an evaluation done? Maybe. Just to satisfy curiosity. There's nothing in terms of how my bike is performing that makes me feel like I need to do so.

 

hey i love learning which is what you've been able to do even more so than the tuner i laid out $375 to do my tune. which is why ive been active here. Im in the process of trying out and figuring out what going on between my legs so I can get the most out of whats there. im talking about the vtwin, btw.
so being lean under low load seems acceptable, but rich / making power under load, and making the most of the ability of the Tune / Map to change that based on circumstances at the moment. Its just a question of methodology I guess. i'm not concerned about running a few points richer if it helps my motor, but if Im saving 10mpg by running 10 degrees hotter than, well, why not, if I can run richer where its under more stress and load. Guess its a lot of tuning theory, and theres various camps. My tuner thought it was best to stick the whole damn map at 13.8 AFR, get correct VEs and turn off the O2s. I disagree with that. Maybe the smoothness Cvaria mentioned is valuable, how quickly you can jump from cruising to full power for that butt dyno torque / passing power is important, which is why Ive spent a lot of time smoothing my tune from lean to rich across the board, rather than 14.6 out to 80Kpa then dumping to 12.5. (I hope).
I spent a bit of time riding with various ones today trying to see if any of them (tuners 13.8 map, my map, or the FM map for 'vibrating engines') worked better. Seemed like mine was honestly the most responsive and pulled the hardest. but I dont know, I dont have a dyno, only the smile-o-meter.
I do know I put down $375 and went from 'my tune' that was very rich @ 65hp to a less rich and more powerful map @ 75hp, and used those settings at the WOT sections of my map. But I would love to figure out what would settle the engine down @ 2K rpm more, its not really lugging but it also is. probably just need new motor mounts, but the engine does seem to dislike 1900-2100 rpm, but thats the best 'sounding' range when Im out and about 2up. but when I have to climb a hill it shakes a bit if I dont downshift which isnt a problem, but if I could get a little more power / torque there without the washing machine action, thatd be nice.

 

Thought I would post the tables from the tune I am running now. 08 xl1200c, V&H long shot slipons, SE/AC. No posting VE tables since they are a work in progress, have done 2 autotunes so far. The AFR table I set myself based on alot of reading and looking at Dyno AFR tables on similar bikes. I also used the PV gauges to watch my engine temp, AFR, and RPM's. The spark advance tables and closed loop bias tables where set by Jaime at Fuel Moto. Btw there is a post in this thread on closed loop biased settings. I called FM and DJ and they said a setting of 700 adjust 14:6 to 14.3. My MPG went up from 42 mpg to 46, engine temp went down from around 390 to around 380 with outside temp around 95. Runs really smooth.
spark advance front


spark advance rear.


front and rear bias the same

 

So is that all FM told you about the CLB voltage? You understand why they are call narrow bands right?



From that characteristic curve you can see that there is only a "narrow band" that is controlled only by changes in O2. Once you go beyond that other factors come in play (in this case temperature). So once you start getting into that 700 mV range or higher, that voltage could be produced by various actual AFR's depending on temperature.

 

LOL I knew you would follow with something. But thats a good thing. Makes me go and read. Is there an article that accompanied the graph?

 

Here is something to read-
https://www.enginebasics.com/EFI%20T...%20Basics.html

 

No... Don't have an article. But the graph itself seems to say plenty.

So what happens when the control loop is trying to seek a set point based on feedback that isn't solely impacted by the factor (in this case AFR) being controlled? The ECM doesn't understand or read AFR. It understands voltage. It's control loop will seek the CLB voltage you set regardless of what that voltage actually means in AFR. Since you are now starting to operate in a region where other factors (in this case temperature) - other that oxygen content - impact the feedback (voltage) provided by the sensor, you can be causing the ECM to seek varying AFR's instead of just the one that was intended/commanded.

Also, what additional impacts come from the fact that once in that part of the curve, large changes in AFR only cause small changes in voltage?

 

Hey T^2.....what is your background? Are you are certified mechanic or an engineer by trade? Just wondering where all this knowledge is coming from....

 

Well with "narrow band" sensors seems to me I only have 3 options.
1. Run with the stock AFR map at 14:6 closed loop.
2. Adjust the table to the AFR's I want which is 14:3 when cruising and
run open loop all the time.
3. Set the closed loop bias table like Jaime did.

Now I am only going by what I have read and that is 14:6 is too lean.
Now from what I got from using my PV gauges on a stock AFR is at 14:6 I was running 490- 400 deg cruising in closed loop. Now running the current tune I posted above I am running 370-380. Now this is just my butt dyno but she seems to run alot smoother and with more power with my current tune. Now based on this table I am below 400 deg so looking at the curve at 400 deg and 700 mv I am slightly less than 1 lamba. Now from what I have read the "ideal" AFR is between 13:8 - 14:1. I am taking the middle road and running at 14:3 closed loop. No doubt widband O2 sensors are the way to go but I am happy with where I am at. Now if they go on sale maybe.