cat over temp, and spark table

[luvmy01ss2]

I was just wondering what exactly the cat over temp enable/disable feature is? Also wondering if smoothing up the spark table (ex. 25,28,33,27 to 25,27,29,31) helps performance or does it hurt performance?

[Chris@HPTuners]

cat overtemp protection adds additional fuel to stop the cats from melting due to prolonged high exhaust temps.

[jimmyblue]

I was just wondering what exactly the cat over temp enable/disable feature is? Also wondering if smoothing up the spark table (ex. 25,28,33,27 to 25,27,29,31) helps performance or does it hurt performance?

COT is meant to save the cats, but it can be heavy-
handed and persistent overenrichment. It is based on
a bunch of calculations about the exhaust gas temp
and the catalyst temperature rise from the chemical
action. If your cats are no longer on the vehicle then
this function should just be turned off. You can
experiment with raising the temperature threshold
and decreasing the enrichment at your own risk;
don't think there's much out there in the way of sound
guidance.

"Smoothing" the timing table in the sense of getting
rid of back-and-forth changes makes some sense. But
what you are looking for most, is to eliminate any
"holes", "spikes", etc. in the surface. The example
shown is more of a "hill" with a trailing edge and might
be perfectly sensible (timing rises for a while with
CylAir and then falls back off, as needed to prevent
knock; "smoothing" it as shown might take away
mid-MAP spark and part-throttle performance "feel",
yet add excess advance at WOT - depending on which
axis this line is along, etc. But you do want to make
sure the timing "surface" doesn't have some funky
anomaly that gives you instant knock, or a timing
bog you just can't crawl out of.