Question from one who has never used a flash tuner so cut me some slack.


If I order a tuner and it comes with a map installed for my Stage 1 mod, does AutoTune change that map and if it does why would I want to do that ?


I always figure the dumb question I ask is the one some one else had but didn't want to.

 

Not dumb. I have the FP3 with autotune. Any preloaded or downloaded map is going to be an "average" map based on similar equipment. It will probably run just fine as long as it matches your setup fairly well. It will probably not be the most aggressive map since it needs to work with a variety of bikes. Using the auto tune will tweak the map based on your actual bike, weight load, riding style, etc. and fine tune the mixture. It is a good compromise between a "canned" map and a dyno tuned map.

 

The basis for all maps are the VE's. Unless those are set first for each cylinder of each motor (assuming the constraints were properly set), the rest of the map is nothing more then guess work.

And keep in mind that any map using an "auto tune" program is using parameters set by the tuning program's manufacturer. Typically, they build in a lot of "safety margin" and those might be more conservative then some owners may want.

 

none of the maps anyone sends you are going to be right for your motor no matter how much you (or they) think it is. It needs to be finessed for your bike, your riding style, and your expectations.

You don't mention the specific tuning device so there are many factors that go along with that choice as well. Piggy back tuners are not capable of the same tuning parameters a flash tuner is.

 

I agree with UltraNutz, a proper MAP will be calibrated for your mods on your bike, a generic MAP is just that. There are more variables in a tuned MAP than just the components you put on your bike. Besides the fact that every engine breathes different there's fuel grades (different regions of the country have different fuels).

 

depending on the autotune unit and the owners ability in understanding a/f ratio, timing and egt the "canned maps" are tweaked by the auto tune feature. Some allow the canned map to be overwritten by the owner installing the tweaked map as the new "canned map".
There are other parameters (throttle position, etc.) that go into the adjustment of maps. Getting familiar with the software, downloading and looking at the canned and resultant data and reading up on optimal settings allow an owner to not only operate the software, but edit maps and understand the bike.
There are other data that goes into the auto tune that allows on the fly tuning that accommodates for air pressure and temp changes incurred while, for example, crossing the rockies and dropping to a coastal town.
My feeling is auto tune has allowed me (whom lives in a rural area with no dyno tune shops) to have a bike that rides optimally with changing conditions.
Lastly, I have no way to verify this, but dyno tune is good for the conditions that prevail at the shop when the tune was done. (temp, elevation, fuel quality).

 

AFAIK, most flash tuners only try to tune the areas in the map where the AFR is close to stoichiometric. The reason for this is that the stock HD EFI uses narrow band sensors that only work near stoich. This AFR is mainly for cruise an not for power. A much better system would be one that uses wide band O2 sensors and allow adjustment in the range of 12 to 15 to 1 (and more) compareed to the narrow bands that only work in the 14.6 range +- a few tenths.. Currently the only full time compete unit that runs closed loop over the whole operating range is Tmax..

http://www.thunder-max.com/

I understand that the Dynojet power vision might start doing full time closed loop soon but expect that it will have a additional attached unit to connect up wide band sensors..

Nice thing about closed loop is that the AFR adjusts automatically.. Changes can be made to the motor / exhaust and intake without having to dyno-tune the bike.

 

There's a lot wrong with this statement.

1: Newer HD's have wide band sensors
2: Dynojet has had the add on auto tune module with wide band sensors since before the came out with the Power Vision, it was used on the PCV
3: Autotune does NOT adjust the AFR tables, it adjust the VE tables.

 

1. How new? From what I've seen they are still narrow band non heated sensors.. When did they change? AFAIK the 72344-10 is still a narrow band sensor..

2. The PCV is an attached unit.. The main reason why I specifically excluded it.. Tmax is a drop in replacement.. Since it is an attached device, it has to trick the original ECM and has certain limitations on what it can do..

3. Not sure I mentioned that autotune changes AFR tables.. How can a power commander change VEs? Closed loop systems in this case are not even sampling AFRs.. They sample O2 to come up with AFR.. How they correct can be a number of different ways? As you say VEs in some systems is one way. Simply adjusting remembered injector PWs is another..

Still not sure anything is wrong?

 

Hopefully without getting in too much trouble I will see if I can clear the VE table questions up. The VE table is Volumetric Efficiency of the engine or how well it moves air at a given set of parameters such as Temp, Rpm, Manifold vacuum or throttle position, and Oxygen Sensor inputs. Changing the VE table is only way we have to adjust the fuel mixture directly. The afr table is only used in closed loop and is a target reference. The VE table and the AFR table have to work in conjunction with each other to achieve the target AFR. If you set the cruise range too rich in the VE table say ideal maybe 85 at 2500 rpms and you set it to 95 there is no way the narrowband O2 can change it enough to bring it to say a target of 14.4 which is pretty common. If you happen to set the ve real low like 75 instead of 85 the bike will likely be surging very badly and the AFR of 14.4 will not be achievable and you will have popping and pinging. With the rich mixture the only short time problem will be poor mileage. This is cruise area only I am referring to. There are several other tables that make changes also and they either change the timing or add or subtract from the injector pulse width. The decel enleanment when made smaller adds time to the injector pulse width at 0 throttle position. The Accel Enrichment adds time if numbers are made larger to the pulse for so many Milliseconds. You can also change the multiplier and do the same thing.
As far as the Power Commander add on they are foolers and do essentially add and subtract from the injector pulse width to richen or lean the mixture. This is what the VE tables do also. We fool them to make changes to the mixture by changing their numbers. They add or remove time from the injector pulse. The ECM uses the % throttle opening, MAP, inlet air temp and engine temp, rpms, and O2 sensor inputs. These are all measured inputs and are not adjustable. You can't use the O2's with a PCIII or PCV as the O2 sensors will send corrections to the ecm to counter the add on outputs to the injector pulse width.
I also haven't seen any widebands on any model Harley from the factory. They are heated and have been since 2010 on Touring models. The old 18 MM in 09 were not heated. When they went to the 12 MM they are heated.
Hope this clears it up some, I almost got myself confused.