EGT

[Tom Cloud]

Dave Williams wrote:

>-> with EGT probes on engines on the dyno.  I think the reaction rate of
>-> the probes is slow enough to make them useless for street mixture
>-> management.
>
> People keep saying that, but I have an EGT mounted on the dash and
>watch it for amusement since the guage cluster replaced the radio and
>tape deck.  Response time is one or two seconds to minor load changes;
>it responds faster to minor changes than major ones, probably thermal
>mass or something.  Since the EGT would be essentially a tuning device
>to build/correct the maps the response time looks useable to me.  Not
>real time control, no, but a useful input just the same.

        [ snip ]

> And of course once you're off the dyno you have no feedback loop at
>all, which makes the EGT look even better.  At least it's telling you
>*something* without hauling the motor out of the car.

so Dave, how do you use your EFT?  If you can't actively vary
your fuel ratio seems t'me all you've got is a temperature.
You need to know the peak (which means varying the mixture
until temp peaks).  Elsewise, how is it of any value?

Tom Cloud <cloud at peaches.ph.utexas.edu>