Originally Posted by
bilemke
You can discuss a change being safe all you want.. How many people here do long term studies of any onecange they make to the PCM in their cars and can say it is for sure "safe"?
The MBT table has been noted as a mean for calculating a theoretical value that is used for torque management.. Right off the bat, we know that is not intended to be a limit. Go grab a 04+ GP GTP file.. You will notice the stock High Octane spark table is quite a bit higher then the stock MBT table in several cells.
Concerning spark, there are other changes I would be more concerned about that seemed to be considered safe by a few (reducing the knock attack rate or increasing the recovery rate because it is supposedly false knock).. Notice GM didnt really change these values over the years..
Just look at the variation in people trying this timing advance change.. How do you know it will be "safe" or lead to "good" results for the variation in hardware (parts) that so many of you are running. However, GM changed it in a stock 04 and 05 and I imagine that much timing advance was not simply a slip of the hand.