To add to what Rode Runner said, you will be targeting an Air Fuel ratio. The safe side of the ratio (i.e. rich) is about 13.0. The unsafe side by most accounts is somewhere slightly above 14.0. The higher the number, the better the mileage. Depending upon your engine's configuration, exhaust, and use you may want a richer setting (your engine has to be able to make use of the extra fuel with higher performance parts).

The Air/Fuel ratio is part of what is called the "map". A good dyno tuner sets the best relationship between A/F ratio, timing, and RPM's to give you the kind of performance that you want for your application. Me, I wanted efficiency in fuel consumption and touring torque.

Most systems come with software that allows you to play with your map. Let's say that you get a dyno tune and you are really happy with the performance but you would like to improve mileage. You spend a lot of time idling at lights, you ride your bike every day, and it never gets very hot where you live. You aren't worried about blowing other bikes off at the light when you're riding to work. So, you can save your old map that was dyno tuned and lean out the lower rpm ranges a little bit, improving your mileage and save the map. Then you can switch between them using a laptop with relative ease.

If you think that all of this is a little over the top for what you are after, and you want a system that will allow you to easily change parts in the future, and you aren't worried about gettting 1 more horsepower or .2 mpg better mileage, then you won't need a dyno tune. You can, with some good advice from the dealer of your ECM, tweak the settings via the software to get what you think you should be getting by modifying the AFR. Then the autotune feature will adjust, within reason, the injector timing to meet your desired target no matter what the weather conditions or the elevation you are riding at. That's good for long distance riders, for example.

The average mileage on my bike is 44 mpg. The other day I was on some pretty vacant back roads, didn't get above 60 mph, and the weather/temperature was perfect and I got 52 mpg. That is because the dyno tuner that did my bike set up the fuel curve so that I had good acceleration but good mileage at lower throttle positions. My bike doesn't have an auto tune feature. If it did, I might see better mileage all the time instead of when everything is just right, without losing performance. I could have installed my own O2 sensors (in other words I wouldn't have had to pay someone to weld in the bungs) and run a closed loop T-Max had I realized that I would want a dyno tune for about the same money back when I bought my new bike.

Since I haven't made any changes performance wise, it hasn't made any difference to me yet. Someday, it will, and I have figured in making the change to a closed loop wide band O2 sensor system along with the performance mods that I want to make to the engine when setting a budget. I don't know if I will decide to get a dyno tune or not. I am hoping that I have learned enough about this stuff to get pretty close by listening to the ECM manufacturer, knowing what I should expect from my performance mods, and my comfort level with the software and let the auto tune do the rest. I think that some systems will even let you do on the go tuning to see what you like while you are riding... I haven't done that research yet, however. They provide you with feedback as to your AFR, for example, along with other data that you can pull over and look at... but don't quote me on that.

 

I will add myself to the list of unsatisfied tmax owners.
I have had zippers look at it at a show where they had it for an hour to tune it. They found that it was very lean at idle and rich in a certain range.
It ran pretty darn well afterwards but before long the poor startup came back and I could again feel it was rich around 3000.
I discovered the email feature and sent them my map.
They changed it and even said it was rich etc.
It ran well for awhile and then is back like it was.
I am tired of messing with a $750 piece of crap that is suppose to be the future. SERT, PCIII other auto tuners will be what I soon go to.

 

sportncruise, are you riding that thing with the stock tune currently?

 

No, I have 500 cams from HQ and zippers said their map for the 575's would work.
They then tuned it twice themselves with it eventually running poorly each time.

 

Actually, I meant now. Are you running with the stock tune and those mods? If so, how is it doing? Lean?

P.S. Sorry you had trouble with it. At least they are hookin' you up. Why not try a different system since Zipper's sells others?

 

Presently I am running the last tune zippers sent which when they sent it ran fine. It has tuned itself out of tune again.

Didn't know they sell others, I wonder if they will do anything for me since they have to have my bike on record of working on it twice with no success.

 

I bet they will. they do seem to go out of their way to make and keep customers happy. I hope they can do the same for you. Forgive me if you already said this but did they try swapping units out to see if it was just a bad box or o2 sensor?

Doh! Scratch that about the different systems from Zipper's. Fuel Moto is who I was thinking of.

 

They have never mentioned swapping units as an option. I might ask about it.
I might try working with them a bit more come spring but selling it this winter while not riding it was my plan. So I could take the money and use it to buy a SERT and dyno tune before the riding season.

 

Good luck. I hope they make it right for ya. Believe me, I know how frustrating this kinda crap can be. I am usually the one with this kind of problem.
My Craftsmen bike jack had one of the "welded on rod" safety stops snap off and almost dump my ride. I took pictures and let everyone on this forum know what happened and I got numerous responses telling me how theirs work great, so I know how frustrating that can be , too. LOL
All I was doing was trying to give everyone a heads up to not trust the so-called safety lock. I use a 2x4 inside it now. LOL

 

I know exactly what ya mean.

I am not trying to bad mouth zippers, I will say only they aren't perfect and I have only seen a small percentage of people with problems. The odds are most will have none.
The PCIII is very well known but most technical people I know who understand how it works such as many of my harley mechanic friends wouldn't recommend it to anyone. But with that said it is very popular.
To the OP of this thread I went to the zippers simply because I wanted to try something different. I had used the PCIII and the Techlusion TFI on other projects.
I have never used the SERT but I have a friend who has used it on 2 of his HD's, 1 103 and the new SE 110 and he is extremely happy with it.