I changed my LS2 heads out for some ported/polished LSA heads so I'm doing some re-tuning. Specs are in my sig. I'm running OLSD with a 50% scaled tune.
I noticed when giving 40%-60% throttle in a tall gear (say 5th) that it would cut out slightly. Air/fuel was good, so I checked spark and it was reading extremely low, like 11*. I thought it might be the "Piston Slap" table, so I zeroed it out. Still did it. The spark tables in the Histogram Display is showing the Cylinder Airmass readings properly scaled by 50%. In my Chart Display and Table Display it is showing the Cylinder Airmass unscaled.
In the pic above my Chart Display is showing Cylinder Airmass at 0.54 g/cyl and the Histogram Display is showing approximately half at 0.28. I assumed that the Histogram Display is directly related to the Main Spark vs Airmass vs RPM tables, which are scaled 50%. What I found is the ECM is using the Airmass readings that are displayed in the Chart Display. So, in the pictures the Histogram Display is showing Airmass @ 0.28 and RPM @ 2000. In the Spark Tables this should be 24*. The actual timing is 19* which is the Commanded Timing for Airmass @ 0.52 and RPM @ 2000. This trend is consistent throughout with some some places showing 11* when commanding 28*. Have I left something out when scaling my tune?
log.JPGspark table.JPG
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Originally Posted by Ben Charles
