I am glad to see this post most of all since I am the average Joe Schmo on a motorcycle engine. I just got off the phone with the guys from Fuel Moto 10 minutes ago with my order. I guess I have three business days to wait.

 

Check out that link I posted (post #16) above for a great thread on tuning with the PV on a Sporty.

 

Will do, Thanks

 

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Rotho- you'll be fine. It really isnt that hard. Only 1% of the work takes 99% of the brainpower, the rest is pretty mindless.

Check out the thread that Canuck Sporty suggested, there are some good tuning points on there.

 

Lol, Thank you sir. I have been reading that thread. It pretty good actually, I found more videos on Fuel Motos website too.

 

I know it's been a few days since this post but since others are stumbling across this I thought I'd throw in my two sense...and yes that's how I meant to spell that.

First, I HIGHLY encourage you to make a decision based on what works best for YOU after carefully understanding what it is you will be doing and the tools available to accomplish your goals. While I use a PowerVision, each person needs to weigh their options and choose what is best for them.

So, let me break this down for you in very (emphasis here on very) basic terms.

How your ECM system works.
That said, you need to understand how your ECM system works. In your stock system, you have sensors that report various information back to the ECM as to what the engine is doing at that exact moment. The Manifold Air Pressure (MAP) tells the ECM how much air is coming into the engine and the Throttle Position (TP) sensor tells it how far open the throttle is. There is also RPM information being sent back to the ECM. These three give the ECM some idea of how hard your engine is working. While cruising, RPMs will be at a low level, the TP will be 5-12% and MAP will be close to full vacuum (MAP is vacuum based...-14.7 is 1 BAR of vacuum and 0 would be the pressure of the air around you. When you are at Wide Open Throttle, or WOT, the pressure in the manifold is about equal to the pressure of the air around you).

The ECM also looks at what your Oxygen sensors (O2) are reading in the tail pipes. This tells the ECM what actual fuel/air ratio the engine is running at. Based on this information, the ECM will control the fuel injectors to try and get the air/fuel ratio where you want it. So, for X TP setting, Y MAP reading, and Z RPM, the ECM will command G amount of fuel to get R air/fuel ratio and it checks the O2s to see if it got it right. If it didn't, it adjust.

Obviously there are a thousand different combinations of TP/MAP/RPM. For instance, going up hill you may see low RPM, mid-range MAP, but a huge TP. So there are a lot of variables that determine what these three readings will be and how much fuel you'll need at any particular time.

All this is how "Closed Loop" works. The ECM also has what is called an "Open Loop" mode. Open loop is when you are not cruising. When you go WOT, things are happening so fast that the ECM cannot wait to get readings from the O2 sensors so it ignores them. It takes what it has learned from them while operating in Closed Loop mode to "guess" how much fuel to command under Open Loop conditions. Part of this guess work comes in the form of your Volumetric Efficiency (VE) tables. These tables basically are the base fuel map (not to be confused with the MAP sensor) that all the calculations the ECM makes are based off of. Having these tables right to start with is the base of any good tune.

How the tunners work.
Understand that the stock ECM tune is designed to run very lean by HD for emmisions reasons. Putting on an air intake and pipes will change the way the engine runs substantially but the stock ECM can compensate for it in Closed Loop. In Open Loop, the ECM may not be able to compensate enough and you can run even leaner under these conditions. Thus most people go with some sort of tuning option to allow the ECM to command more fuel and let the engine run better by running a bit richer. ALL tunning options do this from the XIEDs to high end tuners with a Dyno the difference is HOW they do it.

We'll ignore XIEDs since you're not asking about them but realize they are the first way you can "tune" your ECM to run richer. The second way are the "Piggy Back" systems...the Vance and Hines, PowerCommander III and V, and other similar systems. These systems "spoof" the ECM. They plug into the system between the ECM and the wiring loom and MUST stay on the bike to work. What they do is change the signals coming in from the sensors before sending them off to the ECM so that the ECM will try and "correct" the "problem" and get the reading from the O2 sensors it's expecting.

For example...and again, this is REALLY oversimplified...say you want to richen your Air/Fuel (A/F) ratio from 14.3 to 13.7 (remember the number is how many parts of air do you have to 1 part of fuel...thus 14.3:1 is leaner than 13.7:1). Now if you just tell the PowerCommander to run the injectors more, thus providing more fuel, the problem is the ECM is going to see the rich condition on the O2 readings and command less fuel to try and bring the readings back to where it's programmed for them to be. To keep this from happening, the PowerCommander will "fool" the ECM by reporting the O2 readings at a "leaner" condition than what they are. So while the O2s may be seeing the new 13.7 ratio you want, the PowerCommander is going to tell the ECM that the ratio is 14.3 so that it thinks everything is as it should be.

This is why your service guy was telling you he's seen problems with the PowerCommander. If it fails, the ECM is going to revert to it's stock settings and, if the engine is heavily modified, this could result in a disasterously lean condition. Also, since the device is on the bike all the time you're adding to the complication of the system and allowing more places for things to go wrong. I've heard of corrosion issues in the plugs of the PowerCommander leading to issues. Lastly, to me this is the worst way to "tune" an engine. The ECM system is designed to operate a certain way and to allow it to do it's job the way it was designed is always a best practice to me.

A proper tuner...ie a system that actually re-writes the tables stored in the ECM...is a much better choice and this is what the PowerVision is. You plug it into your diagnostic port, upload a tune, and then you can remove it completely from the bike.

You are also correct that a "canned" tune, ie one that was developed in Michigan but the user lives in Vegas, is only going to get you so close. What you're wrong about is geographical location is but a part of that problem. You can take two completely identical bikes, run them side by side in the same geographical location, and they will still need slightly different tunes to achieve the same exact results. Thus even the tune your dealer is offering is a "canned" tune. To get a tune specific to your bike, you need to scan it while you're riding to see what "real world" values the sensors are reporting and then change your VE and other tables to bring those values to where you want them.

Sounds complicated? It can be. However, this is where the PowerVision shines. You can leave your PowerVision attached to your bike and "scan" the ECM as you ride and "log" that data for later evaluation. Now, you're not a tuner but they have covered that too. You can download a free program for your PowerVision that will look at those logs you create, compare them to your tables in the ECM, and make new tables to try and bring them closer to where they need to be. It makes getting a custom tune REAL easy and the system works pretty good. You can use the basic "AutoTune" (what they call this process) which uses your stock narrow band O2s or you can opt to get their "AutoTune Pro" kit which includes two Wide Band O2s which are far more accurate than the narrow bands and get an even better tune (I went nuts and have both narrow and wide band O2s installed in my pipes at all times...the narrows allow the ECM system to operate as it should and the Wides provide very accurate tuning information...but I'm sick that way).

I believe the TTS also does this but the products from Harley do not. Something to think about.

As for warranty, the product the guy at the dealership is recommending will void the warranty just as easily, or as improbably, as the PowerVision. They are both doing the same thing...re-writing the ECM. Now, WHAT you re-write to the ECM could be really bad, damage the engine, and void the warranty but that's not the product's fault, that's the person who's doing the tune's fault. Obviously if you're having a dealer do the programming they are liable if they mess up. If you're doing it, well, you're liable. That's the real risk you take here. Using the PowerVision though and starting with a canned tune from Fuel Moto is really is a very safe way to go. They are very good and have a ton of experiance tuning HDs. They'll be the first to tell you that all their canned tunes are on the conservative side just to be safe.

Yes, this is long and there's a lot of info here but at least now you, or anyone stumbling across this, can make a more informed choice about what tuning product to get.

 

Just got the Power Vision from the guys at Fuel Moto. Took five minutes to load the custom tune they installed for me. Running the wires to the handlebars looks to be another ball of wax. Do you have to take off the gas tank completely or just raise up the back or front?
I think I'm going to really get to like this unit.

 

I took the tank off and ran the wire down the backbone after I had issues with the unit cutting out due to interferance with the coil and ignition wires. I know others who have just ran it along the bottom and not had any issues as well.

 

Well Canuck I followed your advice and removed the tank. I gotta stop doing crap like this or I'll start to think I'm a mechanic lol. You're faith in the PV looks to be well founded. It looks great mounted and from what little I've done with it, it rocks.