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xmadmax
June 28th, 2009, 12:56 PM
I was working on making a chart to show % of injection BTDC vs RPM and Injector open time vs RPM. I was doing it at 100mm3 and compared a few different tunes, and as I was doing it I noticed that both of the edge evo tunes I was comparing were commanding injector pulse width at fuel pressures that are not on my table (B0720). My table maxes out a 190MPa, while the evo tunes were commanding up to 210MPa.

So does edge just have access to more stuff then we do, or does the ECM just interpolate out to get values that are not defined?

I also attached the excel sheet with the chart I made, its pretty instersting, I don't know if it really tells me anything yet... I am still trying to figure that out

GMPX
June 29th, 2009, 09:47 AM
Are you saying that the commanded fuel pressures (eg B1001) was up to 210Mpa?
The ECM won't interpolate beyond the end of the table, but say between 80 and 100MPa it will sit somewhere between those two values. When it reaches the end value anything above that is just referenced to the end number still.

xmadmax
June 29th, 2009, 10:11 AM
yea the command pressure is over 190MPa, i attached the table.

I guess that might explane the 'flat' feeling when you get over 3/4 throttle. I mean you can feel it making more power untill 3/4 throttle, then after that it doesn't matter how much more you press it doesn't do anything more.

But why would they do that if it doesn't do anything?

FYI, in case you are wondering, I own the edge evo

JoshH
July 1st, 2009, 04:23 AM
I can just about guarantee you the commanded fuel pressure doesn't go over 180. Log it and find out.