power comander all the way at my bike shop we replace the harley ones all the time because they fail after a few years. i know guys with 10year old pc and they work great.

 

i have been happy with my pc3. there are a ton of maps availible for different mods if you dont want to tune. I ran mine for a few years with a "canned" tune it it ran good, i have had it dyno tuned recently and the bike runs perfect.

 

TTS is the best one i think..

 

I was very surprised NOT to see the TFI or Gen3 by Dobecks Performance mentioned.. I have a 09 with V&H slip-ons and HD's SE Air using a TFI... No More running Lean and runs Cooler too, it really works good..

I recently installed SE 255 Cams.. The TFI handled that very well.. TFI is a piggy Back and installs easily and also is adjustable like a carb...
It come with Suggested settings on its 4pots.. The adjustment I needed to do after the install of the Cams ,,, was to turn down on the Green light pot...Yes down as the Breathability of the SE 255's brought More Air and didn't need any More fuel but Less..

I get about 40/42 mpg...

No, I don't sell these. I only suggested you LOOK into them as I have and Save $$ over Other fuelers you don't need for the Light modifications like I (we) have done.. around 250$$ for either TFI or Gen3 by Dobecks..

The best thing is the easy install and It WORKs...

I would never go for the HD download for the stage one as it only gives More fuel at the WOT position and RPM that can damage the engine....
Who wants to rev a 4.375 stroke motor over 5600 RPM in the first place,,,, On the Street ?? maybe the track...

signed....REDHEAD

 

Don't know if anyone completely addressed this but let me try (key word, "try").

Your bike is controled by the ECM, or computer. This computer has pre-porgrammed tables that use input from your various sensors to determin how much fuel and spark advance to command based on specific situations.

One of the inputs it uses under 80% of your driving conditions are your factory O2 sensors. They are not smart sensors (narrow band O2s) and can only tell the computer if it is lean or rich but not exactly how much to either side of correct it really is. However, the computer is smart enough to use this information to tweak fueling needs to get the fuel demands close to what it is programmed for.

Now, in the other 20% of the time the computer "guesses" based on what it has learned during that other 80% of the time as to what your fueling should be. When in this mode, it ignores the O2 sensors.

Knowing that, there are a couple different options out there.

1. The factory download. Harley downloads new tables into your ECM to overwrite the factory tables. This download is very basic and is the same for the particular model of bike you have, not the mods you have put on it. (ie, the download for a Fatboy Lo with SE slip ons and stage 1 A/C would be the same as the one for a Heritage with V&H Short Shots and an Arlen Ness A/C). While better than nothing, the general consensous is this option is only best if you use SE parts on your bike.

DYNO TUNING: If you go this route and then get it Dyno tuned right after you've actually waisted your money on the factory download. The Factory Tune is designed to be an inexpensive "good enough" option for those doing stage 1 modifications (or in the advent you do SE cams/heads/etc, those specific modifications).

2. O2 Spoofs. These devices plug in between your O2 sensors and the ECM. They are designed to Spoof the ECM into seeing a leaner condition than actually exists. This causes the ECM to command more fuel. A very basic option and has no tunability but works for stage one mods for most people. This is the cheapest route but also one of the most generic ways of "tuning" for Stage 1 upgrades.

DYNO TUNING: Like with Option 1, the idea behind the O2 spoofs is to save money. If you dyno tune your bike and have your tuner modify the stock ECM, the spoofs are no longer necessary.

3. Piggy back system (non-adjustable). This is like the V&H fuelpac. It will act similar to the O2 spoofs but will go between the ECM and sensors/injectors/ignition to do more than just change what the ECM is seeing from the O2s. The benefit to this is that you are modifying the ECMs output in a more controlled fashion to get a more accurate result than with just O2 Spoofs. Downside is like option 1, this is just a "canned" tune and has no...or very very basic...adjustments. Again, works good for stage 1 upgrades (with V&H parts if you're using their fuelpac) but you'd need to go with another solution for further mods.

DYNO TUNING: I'm not sure just how much tunability there is in these kinds of systems and, from what I can tell, they cannot be tuned directly. You would have to tweak the map in the ECM and, at that point, have gone with option six down below. Like the factory download and O2 Spoofs, this tuning option is good for a very specific set of parts used for a Stage 1 upgrade.

4. Piggy back system (Adjustable). This is like the PC3 and PCV systems. These systems go between the ECM and it's sensors/injectors/ignition to make adjustments to what the computer sees and what it commands. Two nice things about this solution is that you can always revert back to stock by just removing the device yet it gives you a great deal of customization if you expand your modifications later. Usually these come with just a "canned" tune for your modifications and require a Dyno tune to fine tweak the system. Because of their complexity, they will not use the stock O2 sensors to modify fueling needs. This means it is far more critical to get their settings (or their "map") just right for your modifications and riding conditions.

DYNO TUNING: For this option the devices have "out of the box" maps that will get you close. However, you can further "dial in" the tune by running it on a dyno, looking at what is coming out of the exhaust, and making changes in the device to affect fueling. This is one of the major advantages these systems have over the previous systems we've talked about.

5. Piggy back system (Adjustable with Autotune). This is the PCV with the autotune feature. These now replace the stock "dumb" O2 sensors with Smart (wide band) O2 sensors. This is one reason why these systems are so expensive (wide band O2 sensors are about $125/each last time I priced them). These smart O2 sensors are what dyno shops use when they do their tunes. These sensors give very accurate feedback as to the air/fuel ratio that is coming out of the exhaust. This allows the Piggy Back system to actively adjust the tune as you drive. With this system, a dyno tune is not required to get better performance.

DYNO TUNING: The autotune feature negates the need to dyno tune these devices. The idea behind the autotune is your piggyback system is constantly tweaking the tune as you drive.

6. ECM Custom Reflash or replacement. This is what the SERT does and what the Thundermax allows you to do (but replaces the stock ECM completely). It allows you to physically change the tables within the ECM like the factory download (option 1) but now you can change all the values in those tables for any kind of modification you make to the engine. The benefit to this is that you are adding no additional devices to your bike or trying to "Spoof" the ECM in any way to get the right results and have direct control of the tables in your ECM. The drawback also happens to be the strength of this option. While you can use the canned tune for your modifications, you (or your tuner) MUST know what you're doing when modifying the tables and the SERT option needs a dyno tune to get the most out of it every time you make a modification to the engine. With the Thundermax ECM system, you physically replace your stock ECM with their system. If you get the Thundermax system with Autotune, it now will automatically tweak the base tune using Wide Band O2s. Coupled with the available table maps for different modifications, this eleminates the need to dyno tune the Thundermax ECM with Autotune like you would need to do if reflashing your stock ECM with the SERT.

DYNO TUNING: The main difference between this option and option 1 is that with option 1 you are stuck with whatever the factory map happens to change. Here, you now can change everything and that ability can only really be beneficial if the bike is ran on a dyno and tuned. Otherwise, using a canned tune with one of these devices is not much different than the canned tune of option 1. The only benefit of doing that is that you only have to pay once for the device used to install the canned maps as you make modifications rather than paying the dealer each time to download a new map as you make a new modification. Note: with the Thundermax system with Autotune you get the best of both worlds, making changes to your map directly and having it done automatically with the autotune feature. Thus, like with option 5, a Dyno tune is not required when using the Thundermax with Autotune.


Now, which is best for you...well, that's up for you to decide. There are pros and cons to each...and I've only outlined them...but this is a basic overview of the different types of tunning tools out there.

Some basic thoughts on which option is "right" for you...

1. Is "good enough" good enough? If just getting your bike "close" to right is okay and you're not looking to get that last 2-5 hp out of your setup, then certain options may not be for you. Options 5 and 6 probably are right off the table, with one exception...

2. How far are you going to mod your bike? If you are only going with stage 1 modifications, all of these options will work for you on some level. However, if you are doing more than just stage one modifications then some may be better for you, some may be worse, and some may not be good at all. For instance, O2 Spoofs are stage 1 solutions only. If you're going to do a bunch of big mods at once (stage 1 plus heads, cams, etc), then a factory download will work for you (as they will put all the modification tweaks into the map and download it all at once) but if you're going to do them over time then a piggyback system with Autotune or an ECM reflash/Thundermax with autotune system would be better as it will allow you to make changes as you go without spending any additional money other than the initial cost of the tunning option.

3. Your budget. While you may be able to use either a Piggyback system or a full ECM reflash with dyno tune you might only be able to afford the cheaper piggyback system. Good news is you can always save up for that dyno tune later with the piggyback system.

 

Except for the fact that the ThunderMax is not a piggy back system, it is a complete ECM replacement unit.

 

Thanks for the clarification on that...edit to reflect the change...

 

TTS actually reprograms your stock ECM unit with what ever you want,

 

How can the 'harley ones' fail after a few years? As far as I know the only 'harley ones' are either a dealer-fit map or a SEPST. Neither of these leave anything on the bike to fail.

So, just what 'harley ones' are you saying fail after a few years?

 

An excellent summary and would make a good sticky as this stuff gets asked about over and over.

Couple of minor points...

Not sure that needing to remove the stock O2 sensors is due to 'their complexity'. Rather its because otherwise the stock ECU will read the AFR as rich or lean (as set by the PC) and try to override this and so undo the tune applied on the PC i.e. its more about overcoming a limitation of the PC+stock ECU combination than because its a good thing to remove the O2 sensors.

That might be over-stating it a bit. The SERT & SEPST do come with canned maps (like a PC does) and the bike will run pretty good with these as long as the hardware is a reasonable match to the map, usually most likely if you have HD hardware of course. Some Autotuning with the SEPST afterwards is usually all that's needed to bed things down. A dyno tune is a good idea, of course, but then that's true of most of these fueling solutions.