I agree with the other comments. A couple considerations: 1) New HD touring bikes run very lean from the factor. Even if its completely stock, benefits can be gained from getting the motor a little more fuel (runs cooler, for one). 2) You can get by without fuel management with just slip-ons, since you're not changing the motor's air-to-fuel ratio (only the exhaust flow/sound). 3) Pastor John is right, in that the AN Big Sucker has increased the air intake to the motor (which is what its designed to do), and your stock ECM will not compensate for this. As a result, you're running lean and need to richen the air/fuel ratio. Hope this helps!

 

Does ayone know if the bike has a manifold absolute pressure sensor. If it does and I assume it has a air intake temperature senor and you combine this with engine rpm the mass air flow throught the engine will be known. Now if you change the air filter with a higher flow unit the pressure sensor used for measuring mass air flow will measure a higher air flow and the fuel will be increased to maintain the programmed air fuel ratio. Maybe a Harley doesn't work like this but a FI system should be able to adjust for changes in air flow. If an oxygen sensor is installed the FI can trim the air fuel ratio even better.

 

The TFI from Techlusion is available for 09 Models. I know because I ordered one. They are less than $300 shipping included. Here is the link. It says available for HD 08's but contact them if interested as the 09 models are available. Did some research and these have a good reputation. Check out their waranty, kinda funny.
http://www.techlusion.com

 

nigelgeast, I haven't heard much about TMax's warranty issues...any details?

 

I had the local dealer tell me the same thing about my 06 SG. Took it in for the 1k service, told them I wanted the SE a/c and download done, hoping that would cure the sneeze it had. They put on the a/c but then tried to sell me a powercommander for $$$. I have a friend that has a shop so I stopped to talk to him about one, he laughed and pulled out a box with a half dozen used p/c's and said "You want one of these?" Well, long story short, he put the SG on his dyno, got me about 10 hp and 10 ft lb extra, cured the sneeze and didn't hurt the gas mileage a bit. Find a good tuner, spend the money, you won't be sorry, I know I'm not. I like the stock pipes, the sound kinda reminds me of an old four-barrel carb when I get around 4 or 5 grand on the tach.

 

Yes, our bikes have one of those.

Yes, but you've left out a factor.

Yes. And yes, a Harely doesn't work like this. Probably for the biggest reason that a Mass Air Flow sensor is impractical for the environment, at present.

The system we have works by measuring the temperature and pressure of the air to determine its density. Then it uses lookup tables for values which intersect from throttle-position and rpm axes to determine the amount of air flowing. Now, with the measured density and the hard-coded amount, the fueling calculation can be completed.

There is at least one more consideration in the calculation, though, and it's called the Adaptive Fuel Value (a long-term fuel trim). Whenever the engine is operating closed-loop, it keeps track of the difference from its calculation that it took to produce the correct measured AFR. There are several areas (various by engine/model configuration) where these values are used to update a single fueling factor, which is always part of the calculations.

So if you put a higher-flow airbox on the engine and don't program the lookup tables appropriately, the computer will think the engine's still only flowing so much when in cases it will be flowing more. The computer will provide insufficient fuel and when this happens mostly (if not entirely) outside closed-loop, the corrective factor will remain unchanged by it. Thus, no remedy provided.

If the new airbox flows some better in closed-loop areas, that much better will (probably) be considered in the Adaptive Fuel Value.

But a new airbox really does most of its improving in the open-loop areas of operation so its chances of getting "autotuned"-for are slim at best.

This mechanism is actually quite clever. As an example, if you get a tank of ethanol mix it will require more fuel being sprayed for the same amount of work with the current EFI programming. The EFI detects that something is causing more fuel to be required (because the O2 sensors are responding to the extra oxygen introduced within the fuel) everywhere the same while it's running closed-loop. The current stage of our EFI (so far as I know) does not yet know that the oxygenated fuel is the reason why, but this must be a situation where the same change should be made while open-loop, too, and it takes care of that for us.

Same thing if one/both injector(s) started flowing 5% more or less for some reason; or if the fuel pressure regulator started either saving up or bleeding off too much fuel. You get the picture?

But this system only works as well as it can so long as the airflow lookup tables are properly filled for the running configuration to begin with. Which will not be the case if you've changed breathing gear, cams, etc. and not programmed in the correct airflow figures.

There are several options to either directly or indirectly adjust the fueling. This stuff gets beat to death here on these forums so you shouldn't have any trouble finding page after page full of discussion of them. Good luck wading through some of it...

 

Thanks for all of the good info guys. My bike had the injecters swithed out on it because of motor idle being to low. It was a service bulletin where the changed out the injecters to the CVO five or six nozzle injectors instead of the three nozzle that came stock on my 06 SG. I was also told they did a remap of the ECM/ECU at that time. When i pull the plugs and look at them they have color down 2-4 threads and do not appear lean. However the bike does pop on decel at times. Have any of you had this procedure done on your 06 with the injecters??

 

FWIW: The HD '09 Parts and Accessories catalog says, at page 505, that "All EFI bikes require ECM calibration" when using the SE a/c kit.

 

Thanks for the lengthy description of the FI. I think I understand your description but it still a little foggy about the air density. I understand using the temperature and pressure to get density but I am having trouble with the air cleaner thing. If a high flow air cleaner is installed won't this affect the absolute pressure which will in turn change the density which will change the called up value from the lookup table.

Do all Harleys have the O2 sensor? I have an 06 SG I bought used with Rinehart exhaust and I haven't seen a device that looks like and O2 sensor. Without an O2 sensor is the system open loop?

 

Yes, but to a too-fine degree. Once the butterfly quits being the major choke point, or location of the greater pressure drop, the airbox (if one is used) will show its stuff. Our system still needs to know how much air is flowing, though. Our MAF is effectively done manually with the current parts and hard-coded. At any rpm/TPS point, the amount of air flowing through the system needs to match what's been recorded; either directly, or effectively with a piggyback controller.

Any actual density changes will still be fine-tuned-for on the fly, just like always.

No. O6 Dynas had them first, then 07 (I believe all air-cooled) models got them. Then in 08, I believe, the revolution motors got them, too, so all the bikes in the lineup come standard with them.

Yes, open-loop operation is all that's being used, much less available.

I believe the O2 sensors might be able to get incorporated into the more recent older systems.