P.S....are you a prof. in the engeering dept. at PU??? Make us dig for info., throwing little hints till we find the answer ourselves so we'll never forget?&nbsp\\; &nbsp\\; Love it.......&nbsp\\;

 

No, I am not. But thanks for thinking it anyway. Purdue is simply in the town about 45 miles north from me.

There are not any articles that I know of about our version of Adaptive Fueling. That term is variously used so even if you do find an article, chances are it would not describe what goes on with our current-generation EFI.

What I have pieced together is, in non-specific terms, between 40 and 70 kPa throttle pressure while closed-loop, errors in meeting the target voltages from the O2 sensors are kept track of. These errors are used to develop a single VE table shifting factor per cylinder called the AFV. Adaptive Fuel Value.

All the little errors, which should ideally be the same, are learned anew each time the bike starts. The AFVs are kept in a memory which does not get cleared during power-down, and they help jump-start the error compilation.

 

If you install a set of freer-flowing mufflers, say, there will be errors in the fueling because the flow characteristics of the engine will differ from those programmed into the ECU. Since the flow characteristics will undoubtedly differ non-uniformly from stock, these little errors will not all be the same everywhere. The AFV which gets developed will merely be a statistical average of them.

Since the AFV effectively shifts the entire VE table values either up or down, the open-loop areas of operation will also be affected. Since the flow characteristic differences will likely be non-uniform with the different mufflers, the real fuel changes required will be accommodated fairly nicely in the closed loop areas, especially as those discreet values get re-established during any given ride, but the open loop areas will be modified to match the differences in the closed loop areas. This will likely be wrong correction for the open loop areas.

This is why Adaptive Fueling is a form of auto-tuning, but not one designed for tuning to different parts. Rather, designed for tuning fluctuations while using the programmed-for parts. Does that make sense? Say you primarily ride and fill up in rural areas where smog is not a factor. You visit a large city where they only sell oxygenated fuels to combat smog, and you fill up with it. Now you will be too lean everywhere the same and the Adaptive Fueling will accommodate that for you. Or an injector is slightly fouled and not flowing quite enough. or worn and flowing too much, Adaptive Fueling will try to accommodate that for you.

When you first start your engine, the ECU takes a reading of the static barometric pressure for use as a base value for its calculations. If during an engine-running session you change altitude significantly, or move into or out of a significant atmospheric eddy, the Adaptive Fueling will accommodate that.

It is for fixing things for open loop operation, where it cannot check its fueling accuracy, based on what it could determine in areas of operation where it can check itself. But in order for it to work correctly the ECU VE tables must hold accurate information.

If the tables are not correctly populated for the equipment, the Adaptive Fueling can cause wrong open-loop corrections to be made.

If you compound the situation by having both mufflers and airbox different from the ones you are tabled-for and allow closed-loop operation, the Adaptive Fueling can do very wrong stuff. If you further compound that by altering sensor signals like air temp. or exhaust O2 levels, to the ECU you are really, really rolling the dice.

What do you know? They must have rebooted their Windows server. We can post larger amounts of text for the moment.

 

Wow..thanks Glens....soooooo...keep your car, truck and bike factory stock....

 

&nbsp\\;Get a Thunder Max and it will make all those adjustments for you or is that cheating HAHA

 

Wane713
&nbsp\\;
Did you ever considder what happend when the Thundermax o2s get out of calibration?&nbsp\\;What about what happens when an air leak develops at the exhaust flange? What about all those places in the maps that are only visited for very short period of times and vever long enough for the ECU to home into anything it can work with? How is the timing tuned in on those things without a dyno? What happens to the AFR in areas that have detonation, I think you just lost the overheat protection?&nbsp\\;What about your ability to troubleshoot the bike either with the stock gauge or a borrowed SERT, I think you loose all of that too.&nbsp\\;
&nbsp\\;
There are lots of questions that their catalog does not talk about regarding Thundermax.
&nbsp\\;
AW

 

From everything I've read, "AFV" is the same thing as BLM (Block Learn Mode) in a car (narrow band, not wideband), we're just using different terminology for Harleys. Here is a pretty good link explaining BLM (search for "block learn" in the page): http://carprogrammer.com/Z28/PCM/FAQ...on%20Works.htm

 

Don't they have detonation sensors? If they don't, they should. Detonations sensors, linked to the ingnition timing and not to the fuel management is an often used solution.

 

It does not do any detonation sensing.

 

&nbsp\\;
Daytona Twin Tec uses "BLM" on a harley