I am a little confused on this point. After installing a EFI tuner/manager on my 06 EG, what role does the ECM continue to have?
For instance, if I am not sure if my ECM is "stock" programmed, can that have an impact on the functionality of my dynatech USB III or does the aftermarket tuner take over all functions (at least as far as the fuel injection goes).

 

What the ECM does is modified by the piggy-back tuner, so they work together. The tuner does not replace the ECM and can't work without it. Hope that helps!

 

it all depends on what device is installed.

If it's something like a SEPST, SERT, TTS etc then you connect the device and computer to the ECM via the data bus link on the bike, backup your stock calibration "map", make your tune modifications with the software provided with the device and then write that calibration "map" to the ECM and remove the tuning device. These types of tuning devices become "married" to the ECM so they can not be used to tune another bike but can be used for troubleshooting purposes on any other bike that it will work on. If you want to go back to a stock setup, you would then connect your computer to the data bus link on the bike, write your stock calibration "map" back to the ECM and you're back to stock.

If it's something like PC-V, V&H fuel pak, etc. these are considered fuel management systems and ride piggy back to the ECM. Meaning you plug the device inline with the ECM, make your changes to the device itself, it then takes those modifications and rides on the coat-tail of your stock ECM calibration "map". This device has to remain plugged in on the bike. To go back to a stock setup, you simply remove the device and your setup is back to stock.

To answer your last question; absolutely it will have some effect on your dynatech USB III device. With that being said though, you should be able to use that device to compensate for whatever changes (within reason) were made to the stock ECM calibration "map"


Hope that helps.
Ultra

 

Of course my device is the piggy-back type - it sits in-line and I believe simply controls the EFI aspects of the engine.
With that said, what functions does the ECM continue to perform?
The other thing, is that I am not sure what was done with my bike prior to my acquisition (I am pretty sure the previous owner had installed some sort of tuner as it still had the electrical ties around the ECM). As such, I wonder if there are things impacting the usefulness of my tuner. I don't really want to spend $150 with the dealership to reset my ECM to stock (that's half the cost of the set of the Jackpot slip-ons I want).
My indy said I could spend $200 and take it to a local dyno guy who could zero everything in to my preferences without worrying about existing ECM setup.

 

the ECM provides plenty of "other" functionality but I'm not sure of specifics on your particular model. My 09, everything seems to be tied into the ECM. Cruise, Speedo, Fuel gauge and sending unit, radio... not too much that isn't tied into the ECM now-a-days.
I'd venture to say that things like knock retard, engine timing, some air-fuel compensation are all still part of your ECM among other things as well.

2 things here based on what you've said.
1. if there were wire ties around your ECM then odds are it was another piggy-back style of device which means once it was pulled off, it went back to stock configuration.
2. if you're happy with the way it runs, why fool with it at all?

 

UltraNutz - I still think my fuel economy is no where near where it should be at 36MPG. Heck my shovelhead FLT gets 40MPG.
The bike runs well - without the tuner it would have the occasional "burp" at continued steady RPMs. Never happens with the tuner. Bike had ample power for me stock, but I like for things to run as efficiently as possible. Maybe when I add the new slip-ons later this year, things will improve.

 

my 06 roadking got 45 MPG consistently with a set of SE 255 cams in it. My 09 Ultra NEVER got above 40 MPG even brand new with no mods. The average I get with it with the mods now is about what you stated, 36, maybe 38 in a heavy tail-wind. The bike runs perfect so I'm not fooling with anything. :-)

 

Thats one of the downsides of piggy back tuners, most riders are looking for throttle response and power, riding satisfaction... MPG be.. well not an issue. So the vendors program them to add plenty of fuel.

You can get more mpg tuned piggyback maps, but it takes some sophistication to provide both power and great mpg.

Slip ons will not do anything dramatic performance wise on the street, they may in fact reduce the low end torque. Your bike will sound faster and be more fun to ride, however.

You could get lucky, but you usually have to tinker a bit to get both power and mpg, and you need to know a little about what your doing... which is usually best left to a pro.

And yes, the piggyback simply adds or subtracts fuel, so you end up with whatever the ECU is programed to do plus what the fueler is doing. Both have a affect, but the piggy back should be able to compensate. You just don't know what to set it to without knowing the ECU programmed map... or something like a dyno tool to reverse engineer the map characteristics.

 

I won't be messing with the maps. Been there. Just a bunch a numbers. I will do my part of installing new maps, but won't be tinkering with them. I did compare maps and that was interesting.
Even on the exhaust side, it is not the sound I am looking for - I want it as close to stock as I can get (don't like bothering my neighbors at 6 in the morning when I am going to work) but would be doing it to improve "flow." My old shovel is noisy enough for those fewer days I ride it to work.

 

You can have your ECM read at a dealer, they will be able to tell you what Calibration ID is on your ECM, weather it's a stock cal. a download or a calibration from a tuner such as SERT, SEPST or TTS. If your bike has, say, a stage I download from Harley and you add a piggyback Tuner that is set up for a stage I as well, you're bike would be running rich, which could explain your fuel economy. Another thought, if your bike does indeed have a stage I download, a dealer will be able to "flash" your ECM back to stock, this is a free download offered from HD, your dealer will more than likely charge you a minimum shop fee, probably a half hour labor. But it should be alot less than the $150 you're thinking it is. Either way, IMO it is important to know what your bike has in it Good luck.

Oh yeah, almost forgot. You ECM still controls the speedo, tach, radio, security, fuel injection, ignition, turn signals, and a whole mess of other stuff.