This thread is getting so big its hard to find stuff, but see here for timing computation. http://www.supramania.com/forums/sh...bly-Analysis&p=1712465&viewfull=1#post1712465
Another thing to consider is that the air intake temp goes through the roof on a hot day because the AFM is beside the exhaust manifold and gets heat soaked. Its not unusual to see intake temps above 60C on a hot day after 30 minutes of driving, even though the air intake for the factory filter is in a cool place. That will also reduce power.
So, on a hot day you will see some impact to timing.There is a hot coolant table that retards the timing for coolant above 95C, peaking out at 105C (max correction is 4 deg retarded).
Another thing to consider is that the air intake temp goes through the roof on a hot day because the AFM is beside the exhaust manifold and gets heat soaked. Its not unusual to see intake temps above 60C on a hot day after 30 minutes of driving, even though the air intake for the factory filter is in a cool place. That will also reduce power.