Exhaust Gas Temp

[Jim Staff]

> Now that I am posting; Has anybody ever tried to use exhaust gas temperature
> as an input for engine control ?
> 
> Kind regards 
> 
> Joeri de Haas

As a matter of fact, in one of my travels in the epic of trying to improve lawn 
mower engine efficiency I came accross one such device. It was a themal couple, 
and it used exhaust gas temp to make sure it was being efficient.
  In depth : I asked!
An engine exibits a certain exhaust temp when running at optimum performance. 
This performance is a function of RPM, fuel mixture, surroundings, and it very 
hard to deal with. As your exhaust system may be at say 10¡F (I live in 
Minnesota) when the system starts taking effect it would give you an incorrect 
value. Even if you were to add sentinal values to the inputs such as say it has 
to be at least 120¡F before the system cares, that would be fine if the ambient 
temp of the atmosphere was always the same. In fact the system I saw, I asked to
see it run. The instructer replied "I'm sorry it can't run when the temperature 
is below 30¡F"
  So other than a novelty it's useless..