How are fuel map corrections used in a ecu?

[vuzzi]

Does anyone know how the ecu uses the correction tables?

 

Are the values of the corrections on the base fuel map added or is it a percentage correction for e.g.:

 

Co

Engine temp

Right cilinder

 

And how does a powercommander use it's correctiontable?

[guzzimeister]

Hi

 

the ECU uses a basic table of TPS position i.e. fuelling against rpm. This basic table is modified a few per cent either way depending on what the oil and air temperatures are, the air pressure, and what the lambda sensor is saying about the combustion, The Power Commander simply alters those values for each box in the table depending on what you enter into it. The values given are per centage changes in the original fuelling values for each of the TPS % vs RPM boxes It just adds its values (a tiny voltage correction) to any values in the original ECU map.

 

My advice: don't worry about any of this, just get out there and use it. The beauty of the PC is that if you put in a fuel map that doesn't suit the bike, you can immediately plug it into the laptop and go back to any other mad you like, it takes 30 seconds. You don't need a dyno to optimise the settings although it's easier. I set mine up by trial and error (just like we used to do with carbs), noting the rpm/throttle opening every time I found a flat spot, and then adjusted the value for the combination (and say the two either side of it) by 2%. If it made it better I kept it, if it didn't I deleted it. It took me a year to get it right, but it's very satisfying when you do. And a lot easier than carbs.

 

Any further advice, I would be happy to help.

 

Cheers

 

Guzz

[vuzzi]

I am comparing the maps in the standard ecu with those of the titanium kit. However, they have different values in to maps for temp corerctions (air and engine) end right cilinder.

 

I would like to calculate the resulting fuel injection, to make a good compasison, also with the PC3 maps. So the PC3 used percentual changes.

 

In the ecu map files i read that the map for the right cilinder is an offset map, and looking at the values it gives me the idea that the values have to be added tot the base map.

The temp and also air pressure map are trim maps. I got a feeling these are percentages of change. Am I correct here?

 

And how about the CO-trim? There is no map, and i understood that it works only up to 3000 rpm. is that so?

[vuzzi]

Nobody has any suggestions / ideas? Is this an unexplored area?

[Angelo.M]

According to Meinolf , who's done a test bench simulation with the 15M , right cylinder , start enrichment and acceleration enrichment are offsets to the base map .

Air/oil temp , air pressure and battery voltage trims modify the above sum by percentage .

[Meinolf]

Hi,

 

here's https://db.tt/q479wUGY a description of the interactions of the 15M values I have found so far.

 

Cheers

Meinolf

[vuzzi]

OK, thanks. Good to know which maps are adding or multiplying. Too bad it is not known how the values in the trim maps are used.

 

And how about the CO map. Is it true that it only works up to 3000 rpm?

[Meinolf]

Hi,

 

And how about the CO map. Is it true that it only works up to 3000 rpm?

 

no.

 

Changes of the CO trim value affect the entire rpm range. However, the effect is not linear. From ~2.700 - ~ 5.500rpm the increase in injection duration is more pronounced than below or above those points.

 

This increase is also influenced by the value at B7B3, which can be considered to be a factor applied to the CO trim value.

 

This diagram http://postimg.org/image/4i0nf00c9/ shows the results of CO trim values +50 and -50 while varying the value at B7B3 from C0 to 80 to 40 (hex values).

 

Cheers

Meinolf

[vuzzi]

That's great to know. The extra effect at 4000 rpm is just what I need. I'll try some adjustment soon. 

 

Cheers