Believe it or not... NOT

Phil Lamovie phil at
Fri Jan 21 01:58:52 GMT 2000

How does the hot exhaust gas cool the fresh charge....  is a good
question. Unfortunately it's not the right one.

How does the introduction of exhaust gas lower the temperature of
combustion is a better one.

Keep in mind that the engine is a sequence of discrete events.

The combustion temp is lower beacause there is less fuel burned
and this is achieved by first using exhaust re-entry to help raise the

As the exhaust is 70% nitrogen and nearly 30% CO2 it is very nearly
inert gas. Adding this gas without any change in throttle position
increases the relative compression ratio.

The raised compression allows the engine mapper to
lower the amount of fuel  i.e. increase the A/F ratio to a greater
number prior to the onset of unstable combustion.

The Exhaust gas is NOT suddenly cooled.

your in the pursuit...


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