[Lorenfb]

"Timing control based on IAT is not limited. It's a programmable variable!"

Again, so what! The key variable is ENGINE temp and NOT air temp which is
the MAJOR factor for detonation, e.g. the air temp maybe moderate, but
because of driving conditions (traffic/load) the engine maybe very hot.

"Cylinder Heat Temp is another input that is used by some of the DME (Air cooled engines).."

It's not useful on the air cooled 911 because once the engine reaches operating
temp, the head temp sensor resistance delta changes little.

"A proper Air Mass conversion will use a IAT and the code must compensate correctly."

Hardly, as it will ALWAYS be too little or too much not knowing when detonation
really occurs (a guessing game), i.e. the need for knock sensors and is the reason
all modern engines use them.

Bottom line: Relying totally on temp to control detonation is NOT a good approach!!!!!!!!!!!