http://www.hondata.net/forum/viewtopic. ... =bar#13899
Based on this, I was doing some calculating of my own based on voltage numbers coming out of my GM 3-bar MAP sensor to make sure I had my MAP settings accurate. The numbers started looking all honked up, so I decided to reference an existing setting to make sure I was doing the calculations correctly. It's just calculating slope and intersections of a straight line so I was finding it hard to believe my numbers weren't coming out. Anyway, I took this setting for reference:
Based on these numbers, the calculations are such:
1.554V @ 0mbar
5.0V @ 3167mbar
3167 / (5-1.554) = 919 scalar
919 * 1.554 * -1 = -1428 offset
So, based on the calculations, we are WAY off from the values used to calculate the pressure conversion used in the software of 625 mbar/V and an offset of 42mbar.
If you graph the values I calculated (X-axis = pressure, Y-axis = voltage), with a slope of 919 mbar/V and an X-intersection of -1428 mbar, at the full MAP reference voltage of 5.0V, you come up with 3167 mbar max pressure and 0 mbar pressure at 1.554V. This works!
If you try to graph the input conversion numbers given in the image above, you don't come anywhere near 1.554V at 0 mbar. Infact, based on the X-intersection, you'll need less than 1.554V at 0 mbar of pressure.
What gives? Can someone help clarify this for me? Thanks!