Originally Posted by
ATS4me
S2H, I don't understand what prompted such a harsh post, but obviously I'm not copying anyone's tune because there are no ATS tunes in the repository or posted on here other than my stock tune. I've looked at the 1.4l and Cobalt tuning threads for ideas since the PCM tables are similar, but nothing has been copied.
To see if I'm making more power, I log engine torque, g/cyl, and MAF rate. I use g/cyl as the more important measure because it ties into the high octane spark and knock airmass tables.
I'm not sure what calculated knock is. I log knock retard and timing. As far as I can tell after knock retard goes over about 2, timing starts getting pulled. At about 4* of KR, g/cyl, boost, and desired boost all drop significantly, which makes sense given how the knock airmass table is set up. I have tried reducing timing at higher g/cyl levels and also tried adding a little more fuel in areas where this pops up.
What I've found is in the 2500 - 4000 rpm range, I can run a higher g/cyl in 2nd gear w/o knock than I can in 4th gear. If you can help me understand what might be off, or what to look for that would be useful.