TuneEcu Maps Explained

I suggest that a good place to start in understanding the Triumph ECU and control programs would be to read the Adaptive Fuel Systems overview. It uses correct terminology and explains the system as it pertains to Triumphs. After that there are volumes, literally hundreds of books, written on the subject. Check one or more out from your local library.

The values in the F (fuel) and L (load) tables are NOT of air NOR milligrams of fuel; they are fuel injector "on" time in milliseconds per cylinder event.

The chart/table colors are a visual cue to high light the noted tabular data. One quick look and you can see trends. They are meaningless otherwise. For most riders, the F and L tables, and L to F switch over values are most important. These are "base" values only. The ECU uses these values and then modifies them according to sensor inputs such as barometric pressure, air temperature, coolant temperature, gear position, O2 and so on. None of those algorithms are available for modification in TuneECU (thank God.)
 


THAT SUX!
REALLY SUX
 

I agree with this post for the most part, but for the sake of posterity, i have one bone to pick.... the values in the f &l tables are definitely not injector on time, at least not in milliseconds. For example in my map, the value at 6700 rpm and 100% throttle is over 16000. If it were ms, that would be 16 seconds.... i could maybe believe microseconds, but i think that would then be too low.

I couldn't make a good fit for the numbers being air volume either, though, although admittedly I haven't worked on it very long. The best discussion of it I could find quickly was here . They also came up with mg of air/stroke, although there is some thought it may just be an arbitrary number.

The reality is it doesn't really matter...if you put a bigger number in the cell the computer squirts more fuel. I tend to believe it is an air measurement of some kind as if it directly controlled injector on time, what would be the point of the AFR table?
 
Speedy said:
The values in the F (fuel) and L (load) tables are NOT of air NOR milligrams of fuel; they are fuel injector "on" time in milliseconds per cylinder event.
Click to expand...

Really? That's very interesting. The TuneBoy literature specifies it as milligrams of air (below), and iirc the TuneECU maps have pretty much the same values in the F & L tables as the equivalent Tuneboy (although they index a little different).




Also if the values are actually milliseconds of injector 'on' time, what's the point of the AFR table?
 
Gentlemen, I don't want to get in a pissing match. My statement was based on the data from "Adaptive Fuel Systems Overview" PDF found at TuneECU.org. It was written by Triumph. Tuneboy and Tune ECU may have changed the numbers to be arbitrary (but likely related to hexadecimal code, 8 bit registers and register shifts) but they represent fuel injector "on" time.

Fuel "on" time can be used with only throttle position and rpm inputs. No MAP or MAF sensor is needed. If you use larger injectors, or higher pump pressures, the numbers in those tables are reduced for the same engine power levels. See Claviger's Carp265 map with larger injectors tune for an example. If the values are indicating air weight, and you put more fuel in the cylinder due to a higher fuel delivery rate, the values in the tables would need to be adjusted larger to achieve the same AF ratio. (My statement here is incorrect. With a fixed ratio between air and fuel, reducing air number would reduce fuel flow.)

The AF ratio table is used only for closed loop control. The O2 sensor reading informs the ECU that the exhaust oxygen content doesn't match the AF table using the calculated fuel delivery base value: adjust fuel injector "on" time accordingly.
 
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For the record, I'm reading, trying to learn, and formulating questions.

I wonder if differences of opinion may be, in some cases, just different ways of interpreting the same information. That's what I've found to be true in every subject for which I've ever had an interest.

I hope you guys continue this friendly debate here, wherever you perceive real differences. I actually think it helps those of us with little or no knowledge to gain a better understanding, as more details come to light.

The whole O2 sensor, for example, is an area that I am presently wondering about. The tune I recently installed had the box unchecked, but my sensor is still installed and, pretty much with a wet finger in the air, I decided to check it and see what happens. Well, she runs better than with the "canned" tune, but after insight from @Claviger (assuming I'm understanding correctly) and others here, based on my mileage and other factors, I'm thinking I should get a bung, uncheck the box and, again, just see what happens.

OK, so this, actually, is one of my questions. If trying a custom tune that has been graciously shared by a fellow member with a similar setup, in which the O2 box was unchecked, does checking that box with the sensor in place on my bike hobble, or negatively affect, the tune? In other words, is the O2 sensor fighting negatively against the intended improvements of the custom tune? Inquiring minds want to know.....
 
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And this is why this forum will remain the best around...we actually have people interested in this. I'm just interested in paying a guy who is interested in this level of detail to tune my bike correctly
 

Nope...definitely not my style to argue either. I just want to make sure we get the best info possible as I think this thread will pop up in a lot of searches in the future, and this info is a little hard to find.

The only reference to milliseconds in the 'Adaptive Fuel systems' document is the following chart:

Now for comparison, here is my F1 Map:


As you can see, VASTLY different numbers.

With regards to bigger injectors requiring smaller numbers in the cells, this is due to the fact that you can't tell the computer that you put bigger injectors in. You have to trick it into reducing the injector duty cycle by telling it there is less air moving than there actually is.

I've been noodling around with the numbers, and I can emphatically state the number is NOT mg air/stroke. 2300cc/3=767cc=.000767 cu. m. Using air density of 1.2754 kg/ cu. m, we get .000978 kg= 978 mg/stroke. I suspect it is mg/s, but there's just too many variables. It fits relatively close, but not perfectly.

The factory narrow band 02 sensor can only determine if the ratio is above or below 14.5:1; It doesn't know how far. Any value in the AFR table other than 14.5:1 would then be useless, but in Tune ECU, changing the AFR table values will change the fueling...Likewise with the 02 sensor off, the computer still uses the AFR table to calculate injector time.

If the F tables directly related to injector on time, the computer would have to divide by the requested AFR to get air volume, adjust air volume for density (temp & barometric pressure), and MAP, then re-multiply by AFR to get the correct injector pulse width. Wouldn't it make more sense to start with an air volume number and cut the number of calculations in half?

Again, I'm willing to admit I could be wrong, but the more i look at it the more I'm convinced it's mg air/s.
 

This is one I disagree with Claviger on. Referring again to the Triumph "adaptive fuel systems' pdf you can find on the tune ecu site, it says that the fueling will not be adjusted by the trims produced from the 02 sensor readings in areas of the map that are richer than 14.5:1. This is because the narrow band 02 can only sense whether the engine is above or below 14.5:1, but not how much. The computer then nudges the fuel up or down until it hits that magic number. If you look at the AFR map, only the low load/low throttle area is 14.5:1. Running the 02 sensor will allow the computer to adjust the fueling during cruising to maximize efficiency, but as soon as you roll the throttle open it ignores the 02 sensor and provides fuel based on the F table corrected for air density. Running the 02 allows it to compensate for a particularly humid day, or poor quality fuel for example. Be careful as running the 02 sensor disabled for long will kill it. It has to be heated to prevent water from condensating on it, or it will die. That is the reason for running a plug if you don't want to use it.

If you get the tune totally dialed in, removing the 02 sensor doesn't matter too much (basically like running a carburetor, the system always runs open loop), but for a canned tune I would leave it in. It will make sure that the AFR is at least right in the cruising and idling area where you spend most of your time, which is probably why you notice it running better. My '07 is running a canned tune with the 02 on, and has been for 5 years. It definitely is over rich when under heavy throttle, but it still idles nice and gets good mileage when cruising.

For what it's worth, I'm tuning my '18 with a wideband o2. Once I get the tune dialed in, I will go back to the factory narrow band 02 for the reasons I mentioned above. Also, I'm the first to admit @Claviger has way more experience than me, this is just the way I read the info I can find. I really hope he comes back and jumps in here. Maybe if we all tag him enough it'll light up his inbox and get his attention lol.
 
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