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[Steve Cole]

Everyone can do it different but IMHO there is no need to run the bikes at cruise range that rich. I run them at 14.4 - 14. 25 and they run just as cool as they do at 13.8. The big difference is I can make more Hp and better torque running the slightly leaner settings and get better mileage. So it's all up to the tuner and what he want to spend the time working on.

Let's look at why these things really happen, if the bike makes more heat with less fuel why is that? It's because the mixture being used is producing more power! After all power is nothing more than BTU's of heat! The function of the engine is to convert BTU's of heat into mechanical energy, so let's get the best BTU's of heat we can from the fuel then work on converting it. When you do this mileage and power will all increase.

The base files we send with Mastertune are a little to the rich side and the timing is a little retarded. This is done so that it is safer, not because it makes more power. Every build is slightly different and the NB closed loop system and Vtune will bring it right in to where it needs to be. Going back to open loop is just taking a step backwards.

[Diamondback]

 

Then, HD's setup from the factory should be the best at 14.7 (or close) because they sure run very hot.  Too hot in South Texas.  Bikes ping even with 93 octane.  And mine for sure didn't generate very much power at all.  So why doesn't HD's solution generate the most power. 

If you read the entire thread, I am an advocate of WB sensor's and there benefits(from the auto racing days and my vettes). I understood that you increase AFR during times of acceleration (and cold condtions) to keep head temp's down, pre-igintion and other things.  Thus 14.7 is the theoretical point where all the air is burned up with the mixture of fuel.

I wasn't aware this was where most power is generated.  So HD is running the bikes as lean as possible to burn as much fuel per cycle as can.  This yields a condition where the margin for error is too small.  Interesting question, why is then that both of my bikes ran the best at 13.8 at cruise and both tuners setup the bike there.

And with both they actually increased the timing with no negatives.

I assume this is Steve from Fullsac and your reputation precedes you.  Maybe I should just reset the AFR to 14.2.  I have a couple of engine manuals that recommend 13.5.

I guess it is the margin of safety.

Thanks for the insight.

Wish I had known about your product before went with the WB solution, although, it runs with any other bike both power and gas mileage.

 
 

[HD Street Performance]

14.7 is the theoretical point where all the air is burned up with the mixture of fuel.

Which is a cruise idle and light load setting most power and economy. There is confusion about the term power and WOT on a dyno is just one set of data. Going through the gears and normal riding under lighter load can benefit from a leaner mixture. Throttle response and fuel consumption both benefit.

Raise the load up over say 60-70 MAP and the 13.8-13.3 is a lot more palatable. In the Delphi or TTS maps you are now out of closed loop (based on the original setting for closed loop) anyway and running on sensor input and VE numbers.

You may find more throttle response and economy with the Tmax by tweaking the map. Many others have. Zippers doesn't support those mods well and the user community has done a much better job of dealing with the possibilities. Zippers will just have you change a map and redo the offsets. The idea is to change the target AFRs and adjust the timing for improved throttle response and ping control.
It can be done and you may be surprised there is even more suds and economy left in your motor.

There is some advanced tuning techniques for Tmax here
http://harleytechtalk.org/htt/index.php/topic,17117.0.html