This image is the entire Map data section of the ECU flash converted to an 8 bit grayscale image 160x160



You can see the repeative patterns with minor variations if you copy it and zoom in on it with a graphics program.



-- Edited by RidgeRacer at 17:32, 2006-12-19

I was reading a thread on anothe site where someone was talking about modifying the water temp signal to the ECU to richen the mixture when they activated their nitrous system.

The nitrous shot adds more oxygen to the combustion and requires more fuel to keep the A/F ratio correct. The ECU runs the bike rich when its cold, like a choking a carb bike, and uses the water temp to determine how much fuel to add.

The water temp signal is a simple resistor to ground that changes resistance with temperature. Their idea was to use a relay to disconnect the temp sensor and substitute a resistor of a known value when they hit the NOS switch. What value resistor should they use?

I went through the software and found the following two maps





The first map confused me at first. I expected to see an increase in fuel when the bike was cold that would rapidly fall off as the bike warmed up. It turned out when I looked at the software closer that the first map corrects for the non-linearity of the temp sensor and makes it linear. The second map is the acutal fuel vs temp map.

After tracing out the internal temp sensor schematic of the ECU and using the map data I came up with a method of selecting the amount of enrichment you want.

1) On the bottom map select how much enrichment you want on the Y axis 0-70 (at this point I still don't know how much actual injector duration that translates to)

2) Go across the bottom map and find the intersection, then down to find the corresponding X axis value

3) Take that value and find it on the y axis of the top map. Go across to the intersection and down to read that x axis value (1-29)

4) Find that value in this table which shows the voltage required and the resistor needed to get it in K ohms

---Volts---K Ohms
01--0.29----0.112
02--0.45----0.178
03--0.61----0.248
04--0.76----0.324
05--0.92----0.405
06--1.07----0.493
07--1.23----0.588
08--1.39----0.691
09--1.54----0.803
10--1.70----0.927
11--1.86----1.062
12--2.01----1.212
13--2.17----1.378
14--2.32----1.564
15--2.48----1.772
16--2.64----2.008
17--2.79----2.278
18--2.95----2.589
19--3.11----2.951
20--3.26----3.378
21--3.42----3.889
22--3.57----4.512
23--3.73----5.289
24--3.89----6.284
25--4.04----7.604
26--4.20----9.439
27--4.36---12.164
28--4.51---16.632
29--4.67---25.306

See how easy

-- Edited by RidgeRacer at 17:34, 2006-12-19

I wasn't aware of that. I'll mention it to them. There may be a an additional ignition map I didn't specifically look for one.

Learn something new every day

I created a rudimentary ECU definition of the '02 ZX-12 for the Enginuity Map viewer/editor from Enginuity.org Here is a 3D image from the software.




You can view the map data and in the case of the 3D maps create a rotatable topo map image.

As I go thru the code I will update the definition so that the X and Y axis will show RPM, Throttle Postion, etc and the data will be in actual fuel amounts delivered. Right now it is just the raw data.

[EDIT]

I've seperated and moved the files to the
You can find the Viewer Software, Map file, and latest Map definition in the Map Files Download Thread. I seperated them because the map definition file is the only one I will be changing as we go along. No need to re-download the others files.






-- Edited by RidgeRacer at 17:35, 2006-12-19

Boy, you can really see the resonances in the stock system in the fuel map especially. A lovely rising sine curve with larger throttle openings, totally textbook for having an intake, cam timing and exhaust that all are tuned with the same resonance.

The ZX-12R is better behaved with coolant temp adjustments than some bikes out there. Hondas in particular are notorious for going pig rich if you get the coolant sensor much over 205 F. The bike becomes a real bear to ride, and non-responsive to the throttle. I wouldn't be very happy with fooling the ECU with coolant temp changes, looking at the course stair-steps on that map. Not a very accurate and repeatable way to change your mixture... This is why aftermarket companies abandoned that strategy in the motorcycle market a long time ago (the Power Commander II was the main unit using that strategy, and it was replaced some time ago in all markets, AFAIK, with the PC III, which alters injector pulse width).

Yeah, I think we can learn a lot from each other. :D

I do sell copies of my book outright, signed if people want. :) I usually ask $20 plus shipping; it's a shade more than Amazon.com, but not a huge amount, and I make a bunch more selling them myself (not that I get a whole lot either way!).

If the cams, intake and exhaust are all tuned to make best power at a certain engine speed, you will tend to see the torque curve changing in a sine curve at different engine speeds with the throttle wide open. You're seeing the resonances of the individual parts working together, and like any resonant system, you have a peak and a valley that are harmonics of the tuned frequency. I'm slightly surprised that Kawasaki set the bike up this way; presumably they did it to be able to advertise very high peak bhp numbers, and possibly to push the potential top speed a little for promotional purposes as well. Typically, manufacturers will have the different tuned bit set to different resonant frequencies so that the valley on one part is canceled by peaks on one or more other components; this gives a very smooth torque curve if done right, which means predictable and even throttle response, which makes the bike easier to ride AND more confidence-inspiring, too. They have added flappers in the airbox and valves inside the exhaust system on many newer bikes to allow power to be increased across the board by changing the resonances of the various components, as well as keeping gas velocity high at lower engine speeds and smaller throttle openings. Much like variable length intakes and variable valve timing in cars, it re-tunes the systems for best power over a much larger operating range.

I've figured out how to convert the ignition advance map data to actual degrees BTDC




Referring to the Diagram above:

The timing wheel is shown with cylinders 1 and 4 at TDC. You can see that the sensor is mounted 10 degrees off the TDC line. This means that when tab 8 is directly in front of the sensor the crank is at 10 BTDC. Which is the idle timing advance specified in the manual.

In looking at the software I find that actually tab 7 would trigger the Coil timing calculation. It would pull the value from the coil maps shown above and then subtract it from 67.5 degrees. The idle figure, and lowest value shown, in the map is 64. As explained above this is a fraction of 90 degrees, 256 being 1/1 and 64/256 = 1/4 = 22.5 degrees.

Now when tab 7 is in front of the sensor 67.5 degrees in the future is half way between tabs 1 and 8. Of course 67.5 - 22.5 = 45 degrees. 45 degrees after tab 7 is in front of the sensor would be tab 8 in front of the sensor or as stated above 10 BTDC.

So the formula ends up being 12.5 - ((mapvalue / 256) * 90) = degrees BTDC

I'll update the Enginuity definition with that formula and post a new map in degrees BTDC