Recently I was tracking the IM pressure and Engine Load on my OBD-2 scanner and when I saw the chart it was interesting to see how the engine load is like a mirror image of the intake manifold pressure. I used Kpa intead of inHg or psi as units for IM pressure so I can use the same axis/scale on the chart.
In the below image, Blue is pressure, Magenta is Engine Load. (Yellow is timing).



Notice how timing is also mainly affected by IM pressure.


Then I was curious to see at what the IM pressure (and thereby engine load and timing) typically is at what throttle position. Here's what I got -
Blue is pressure, Red is throttle position, yellow is timing.
Interesting to see that around 30% throttle the engine load is already 80-90%.




anybody know where I can find a timing map for this motor (sig) ?

Sampling rate is about 3hz per sensor. So about 8-9hz total.

 

Can't help you with the timing map, but what app did you use for the OBD2 datalogging?

 

actually I used wOBD for logging the data and pulled the file into Excel to create the chart (wOBD does not have charts, but its free!).
The hardware is OBDPros.com .

Some commercial apps are good but cost almost as much as the hardware.

But there are some free ones that I'd like to try - like FreeDiag.



Modified by AnAccordIsForever at 1:48 PM 3/14/2007