What affects to the idle spark timing? Minus spark timing..

[shinysun]

Hello,

As the weather is colder, I noticed the rough sound from exhaust , then I checked the spark timing showing -3~-2* degree.
On the log of a day before the above, it showed 14~16* degree.
After searching the site, there was the similar question.

At idle, minus, but going back to normal as the car moving. The post said the ECU is trying to get RPM down with minus timing due to many reasons like air leak.
I checked any leak on the system, but seems not.

I am wondering what affects to the idle spark timing? I understand just after start, it pushed the timing to get the temp up.
However, after long driving, it still shows minus timing. Is it bad?

Nothing wrong, except the sound. If I accel, everything is working good.

Thank you,

[Higgs Boson]

torque based controllers, adjust the torque model

[shinysun]

torque based controllers, adjust the torque model

Thank you,

How can I adjust the torque model at idle? By changing the Max torque timing vs. RPM vs. Cyl air table?

[shinysun]

17-11-02 12-33-08.hpl17-10-26 22-22-20.hpl

Here are my logs.

The setting is the exactly the same, but the first one has minus spark timing while another one has 15~18* positive timing at the idle.