ECU/spark advance/MEP

[digi]

Hello,

As everyone knows, I'm a newbie, and I'm trying to decipher how the ECU
operates exactly, perhaps not in a electrical sense but in a fundamental
sense.

I hear talk about a spark table, I'm assuming this is a refrence table for
ignition timing. Is it a multidimensional table? What factors does the
ignition timing depend on? eg; rpm/maf/temp/map

What about injectors? Do they operate on a static crank event or do they
have variable timing as well? eg; give them a slight headstart at higher
rpms.

This is not really ECU related - but, is there a way to measure the MEP in
a cylinder on the street? MEP being maximum effective pressure, the peak
pressure in the cylinder after ignition.

Also, what about coolant/oil/exhaust temp? This subject has been beat to
death before, I have refrenced the archives, but, have failed to
understand what each fluid and its temperature affects. I have refrenced
the archives already.

I realize that specifics are unique to each type of engine(eg; cylinder
temp affected more by oil or coolant), however, I am just looking for a
general/typical answer.

What about EGT? I have heard that retaining heat in the manifold/headers
close to the exhaust port increases velocity requiring less work by the
engine.

Would a thermocouple close to the exhaust outlet on the manifold/headers
suffice for a quick-acting EGT sensor? Or must the thermocouple be in the
airflow for adaquate effectiveness?

What about nitrous on EFI applications? Can you just burn a new prom? Do
you measure the nitrous flow? Whats the ideal mixture of
nitrous/air/fuel? I have seen advertisements for nitrous on EFI
applications but have not seen any information on what changes the ECU
takes.

Last thing, I saw some mention of a cone-shaped heater that converted the
gasoline to a gas state prior to entering the engine, and was patented but
dramatically increased milage. It said there was a mention of it in the
archives but I've failed to find any information on it.


Thanks all,

- Brian