Had a stage 1 SE air cleaner and slip ons put on my 07 Dyna. Added a Race Tuner and Dyna Tune. Dealer provided a dyna graph and my question is this. They (the dealer) is saying my air/fuel ratio is set at 13.1. Does this make sense? I've heard the target is 14.1?

 

Did your dealer provide you a copy of this map? If so, please attach it here. I'd like to see what they did with you're air/fuel tables.

If they indeed set your A/F tables to 13.1 across the board, imvho, they did you no favors.

The AFR should NOT be one set value across the board. The AFR is a valuble tool to manipulate in order to get gas consumption at cruise load and throttle, or better accelleration under wide open throttle.

I like to have an AFR of 14-14.5 at cruise speed and throttle, but under 100% WOT I like to see it at 12.8-13 in order to cool the combustion chamber as well as decrease the chanse for knock.

One-fits-all does not apply to AFR settings, as far as I'm concerned. :2cents:

 

If you had it dyno'd, the actual AFR is right there on the bottom of the dyno printout sheet. How they got there is another story.
More important question, how does it run after the dyno tune?

 

I'm still trying to figure out why you would want WOT at 12.8-13.0 a/f? I assume if you are at WOT you are wanting the bike to pull hard, create power... isn't the most power created between 13.1 and 13.5/6? Is it just to cool down the engine? Do you run WOT that long? I think I have mine set at 13.1 through about 5k rpms then drop it to 13 the rest of the way...

Is 12.8 a longevity thing or a performance thing?

 

Oh, sorry... as for 13.1 accross the board... it won't give you the best fuel econ for cruising... that is the richer end of the "ideal" power creating 13.1-13.6 a/f spectrum. When the engine ain't working hard, and you're just chillin' can be up in the 14s with not problem, and will increase your mpg. But you should check out the A/F at the bottom of your dyno sheet... seems odd though... you need the table set at 14.6 to use to "closed loop" system... I don't know why they would bypass that... you tweak that on another table...

 

The V-Rod runs to 9,000 RPM, Mine runs out to 9,600 RPM. I'm trying to bump the timing to get some better pull, and I'm trying to keep the engine from knocking. So I set it as rich as 12.8 as I'm approaching redline, and the power starts to fall off the curve. (It's more of a safety thing, in the case that I miss a shift and bounce the rev limiter.)

 

28: It's unlikely that the a/f was "set" at 13.1 for all of the various rpm, load, throttle positions. If you have the SERT software, load it on your computer and read the instructions/basic info.

For WOT, the a/f is richer in the lower rpms because the fuel does not atomize as well as it does at higher rpms, so more fuel is delivered to compensate for the less than ideal atomization of the mixture.

Ignition timing also effects the burn. At a given rpm, load, and throttle postion, fuel can be added to what is already say a 13.8 a/f, and by bumping the timing slightly, the burn is improved and a/f remains 13.8; but, because your are getting more fuel burned the bike makes more power. Of course, a point is reached where adding fuel and/or bumping timing don't make more power than the previous fuel/timing setting, so you revert back to the last setting. Going through that process for each rpm, load, and throttle position is why dyno tuning done well is time consuming; shortened substantially by the tuner's familiarity with the build.

 

It is my understanding that the set afr and the actual afr will be different. I thought they were trying to achieve an afr of 13.5 measured with a sensor in the tailpipe. If you look at the map and you have red boxes set at 14.6, your closed loop system is trying to achieve approx. 14.1. I wound up setting taking mine out of closed loop and setting most of the 14.6 boxes to 13.9 to richen things up a bit which helped with heat and eliminated a pinging problem I was having. 13.1 seems a bit rich but if it runs good and mileage hasn't dropped off too much should be fine.

Marc