Using commslog ....... and logging timing..... what does that value represent and how can you tell if you had a knock event that the ECU pulled timing for?

Here is a portion of one of my runs....This section reads all 118 but while in boost I see it go from 120-118. I just want to know how much of a change that really is.

TIME--RPM-TIMING
6.23,6776,118,
6.24,6792,118,
6.25,6792,118,
6.26,6804,118,
6.27,6830,118,
6.28,6830,118,
6.29,6850,118,
6.30,6857,118,
6.31,6857,118,
6.32,6877,118,
6.33,6877,118,
6.34,6884,118,
6.35,6884,118,
6.36,6903,118,
6.37,6918,118,
6.38,6939,118,
6.39,6958,118,
6.40,6958,118,

 

Anyone know what those number really translate to?

 

You might want to change your logg into a csv file, it goes to exel and is a LOT easier to work with! Thanks to Sackett for this tip, it makes logging a lot easier....

 

To translate to degrees, subtract 128.

118 -> -10 degrees

d

 

see, shouldn't i have numbers like that on the pyxede log? or not?

man, im really sorry for all of the questions...i would just really like to get a grasp on this stuff!

 

You sure about that?

On a 0-255 scale with 128 = 0deg, I would think that 118 corresponds to either -2deg (from the documentation about "double retard") or -1deg.


EDIT: ^^^ that's looking at the "timing offset" maps (e.g. SMART timing with +/- 12.7deg). In the regular timing map (typically setup as +/- 10deg), I think 118 would correspond to -1.56deg or -0.78deg.

 

No. Xmap just gives the raw signal reading (0-255). pyXede actually knows what the signals are on the evo and applies the appropraite transform. For example, you don't see 0-255 for AN1. Instead you see AFR. You don't see 0-255 for RPM. Instead you sell, well, RPM.

d

 

Well this is taken directly from chiptorque documentation:

" ("Crank timing out (tuned timing shift)","0 = -max?; 128 = 0?; 255 = +max?")"

d

 

OK, and what is -max and +max?

In the timing map, it's +/- 10 deg (but can be changed to +/- 1, 2, 3, 5, 8, 10, 15, or 20 in pre-3.2 versions of XMap).
In the SMART timing map, it's +/- 12.7 deg.

 

I know this but the number would still be 118 and I have no idea what that refers to.

I doubt it means -10 because that would indicate heavy timing retard correct?

 

I was under the impression that it's also +- 128. I'm probably wrong. :-p

This is true, but those authority ranges are used for the Xede's internal programming to modify the signal. While these can be changed, the actual range of the signal must be fixed otherwise the ECU would get really confused.

d

 

This still doesn't make sense to me......why would I see negative timing all the time?

Even at low RPM cruise?!?
2700 124 -4
2705 124 -4
2705 124 -4
2712 124 -4
2712 124 -4
2722 124 -4
2722 124 -4
2736 124 -4
2752 124 -4
2752 124 -4
2768 124 -4
2768 124 -4
2786 124 -4

Then at WOT

6523 120 -8
6545 120 -8
6559 120 -8
6588 120 -8
6595 120 -8
6604 119 -9
6620 119 -9
6620 119 -9
6641 119 -9
6646 119 -9
6655 119 -9
6655 119 -9
6655 119 -9
6663 119 -9
6671 119 -9
6671 119 -9
6690 119 -9
6723 118 -10
6734 118 -10
6750 118 -10
6753 118 -10
6776 118 -10

 

*sigh* I'm sure I'm going to get this wrong, but here goes.

There is no "timing" signal. What you actually modify is the crank angle sensor. So to apply a postive timing value, you apply a negative value to the crank sensor. The ECU is fooled into thinking the crank is at a different location and then does its thing.

d

 

The authority range of the signal is defined in the map's parameters.

In XMap V3, try making a map that uses "timing change" and a range of +/- 1. Watch the graph as you hit Page Up or Page down on a cell in the map. I have to hit Page Up 7 times before the displayed value goes from "0.0" to "0.1", and another 13 times before it shows "0.2".

So, in the case of a +/- 1 deg map:
128 = 0
129 = 0.007874016
130 = 0.015748031
131 = 0.023622047
132 = 0.031496063
133 = 0.039370079
134 = 0.047244094
135 = 0.05511811 (shown as "0.1" due to rounding)
136 = 0.062992126
137 = 0.070866142
138 = 0.078740157
139 = 0.086614173
140 = 0.094488189
141 = 0.102362205
142 = 0.11023622
143 = 0.118110236
144 = 0.125984252
145 = 0.133858268
146 = 0.141732283
147 = 0.149606299
148 = 0.157480315 (shown as "0.2" due to rounding)

135 - 128 = 7
148 - 135 = 13

 

Correct. The Xede can't calculate ignition timing from the CAS signal alone.