Playing around with the 2.7 software (ECU and TCU)

[RTB]

As an example of what I am currently seeing. This is just from one duration map, as we do have five.

In all tables, Throttle position on top, RPM down the side. This creates some static values as I don't call for high fuel at low RPM, so some numbers at lower RPM are constant. Equally, above 2200 rpm and 65% throttle I call for full fuel, so values in this range are also constant in this example.

Start of Injection (deg BTDC) and fuel rail pressure.



Injection duration (degrees of crank rotation) and End of Injection (deg ATDC)



Midpoint of injection (degrees crank rotation). I have seen other tuning sites that use a ratio here, but this kind of makes sense in my mind. A value of zero means the SOI and EOI are perfectly centered around TDC.



It all looks reasonable to me. What does the wider community think? Right track, or way off the mark? Have I got my calculations all stuffed up??

[RTB]

OK, so after some time in the spa, I am doubting the wisdom of the youtube teachers now. Maybe the WJ is a little different.

Just calculated SOI a different way, and I'd say it looks slightly more reasonable.

Start of Injection (deg BTDC) and fuel rail pressure.



Injection duration (degrees of crank rotation) and End of Injection (deg ATDC)




Midpoint of injection (degrees crank rotation). I have seen other tuning sites that use a ratio here, but this kind of makes sense in my mind. A value of zero means the SOI and EOI are perfectly centered around TDC.

[RTB]

Well, this thread was about sharing so here was my journey below.

Not all maps in the ECU can be taken on face value. Some need an offset, or a multiplier, or both to turn them into something readable. So I started looking at forums and YouTube for info from others on what the SOI and Duration maps needed. Many forums mentioned a multiplier of 0.023437 for the SOI and Duration. This is what I applied to the first set of calculations, and the result looked reasonable, but did leave a couple of spots that had me questioning it.

Even though the initial image of the SOI map I posted was in raw form, JeanLuke challenged the numbers which helped me to remove my blinkers and look at it another way. Strange thing is that while looking back at earlier posts in this thread for information for someone else, I actually saw that the mighty AdrianD had already given the answer.

So the second set of calcs was done using a time based conversion to crank angle for both the SOI and Duration maps. This has resulted in what looks to me to be the right way forward.

Take the value from the map and convert it to milliseconds. Find the time it takes for 1 revolution of the engine at the chosen RPM in milliseconds. Using the ratio of these two numbers, multiplied by 360 gives the crank angle.

At 4000 RPM, the engine completes 4000/60 = 66.67 cycles per second. Therefore, the duration of one engine cycle is 1/66.67 seconds or 15 milliseconds.To calculate the number of degrees of crank rotation for which the fuel injector will be open, we need to convert the pulse width from microseconds to milliseconds. 382 microseconds is equal to 0.382 milliseconds. The number of degrees of crank rotation for which the fuel injector will be open is given by, 0.382 / 15 ​× 360 = 9.2​ degrees
Therefore, the fuel injector will be open for approximately 9.2 degrees of crank rotation. What is important to remember though is that this is the time the injector is powered, the actual open and close time is slightly delayed.What I can't tell is if this mechanical delay is compensated for inside the ECU, or if the real world injection will just be slightly retarded from desired.

Now, the search for any other SOI, Rail Pressure, or selector maps needs to begin. If anyone knows any other addresses and dimensions of other maps, any chance you can post them up? Map searching is less fun......

[JeanLuke]

The search for maps includes the relationship between hydraulic fan speed and air conditioning system pressure. I know it is in there somewhere, but cannot find it.

[RTB]

Originally Posted by JeanLuke

The search for maps includes the relationship between hydraulic fan speed and air conditioning system pressure. I know it is in there somewhere, but cannot find it.

I shall keep that in mind while searching. What sort of numbers would you expect to see on air con system pressures?

[JeanLuke]

It seems to start ramping up the fan at around 16 bar pressure. I have not seen it drive the fan much more than about 40%.

[JoeTe]

Hi guys!

I tried somes mods on SOI in my jeep

EOI normally should be around 5-10 ATDC optimal and maybe you can go until 20 ATDC if the car is heavy mod but a lot of EOI will give you smoke and high EGTs that of course you dont want . A lot of people said that for tunning economy play with SOI and with "n75" of turbo(lowering boost in that areas). Im not a freak of fuel consuptiom because I only use my car for offroad so Im not interested in that way.

A lot of people advance SOI in EGR range (if you have OFF) I did although I cant feel differences but SOI should go in upper way and you can see in stock map that in some parts are decreased (like in all cars) less EOI will reduce emisions.

A lot of people say that for find optimal SOI (at least for performance) you need go to dyno others said that did some test and only notice was the noise. and dont see too much diferences in power just keep eoi in that range (5-10 atdc).

My conclusion probably if you go with EGR off I increase that area and mod higher areas to try to keep 5-10 degrees or at least dont go more than 20 degrees
Our SOI map is conservative and I think very bad high IQ range if you go near to 100mm3 to fuel SOI is very high becasue SOI is only 17º if you compare other engines like M57 of bmw or even C30 amg the SOI could be around 22 degrees in this range (probably you have avoid go more than 30 degrees).
C30 SOI map have a lots parts wih 3-4 degrees more than our SOI map

Duration maps was scaled until 100mm3
Stock at max power - 4000 rpm run with 60mm3, SOI 16,71 BTDC and EOI is fine, around 9 ATDC
instead
If you go 4000 rpm with 100mm3 - SOI still is 16,71 BTDC and EOI is 25 degrees so In my opinion you should increase SOI around 24 BTDC and your EOI will be ~17 ATDC and if you can increase rail pressure to 1400-1450 you will have better EOI too. Of course with 100mm3 at 4000 rpm you will have around 270hp