Ignition Timing

[Dras]

I am looking at designing my own hybrid interceptor / standalone ECU and I have a question regarding timing strategies that I was hoping someone could answer.

According to the workshop manual, amongst other things, the ignition timing takes into consideration the atmospheric pressure and the intake air temperature. What factors do these 2 sensors play in ignition timing?

[Bennoz]

Atmospheric pressure and air intake temp are directly relevant to iginition timing, if the atmospheric pressure is low & the air temp high, that leads to poorer quality combustion - which equals slower combustion. As combustion conditions improve (higher pressure & colder air) its necessary to advance iginiton timing to compensate for that combustion speed increase.

Hope that makes sense..

[Dras]

Yes, thank you it does.

For what I am planning, I will need to know exactly how much to retard / advance timing based on various pressure / temperature readings so I think I will invest in some books on the matter.