after-run modification/addition

[Brett Dikeman <brett@pdikeman.ne.mediaone.net>]

Greetings all,

This may be of interest in particular to those that do track events and
have problems with heat soak, or those of us that like to fiddle all the
time with our cars(or have no choice, right Phil? :)

On the turbo cars past about 86(I assume the UrQ's are similar), there is
an after-run switch that activates and turns on a small can pump and the
Stage 1 of the cooling fan.

I added a toggle switch, which I tie-wrapped to the
top-of-radiator-to-top-of-coolant-resevoir hose.  I used a bunch of crimp
connectors so that my "harness" plugs into the sensor and the original
plugs.  Works very nicely, and the switch+solder connections are
heat-shrink wrapped.

In a quick test, with the engine at normal temp(tad left of the "center"
mark) I managed to get temps down to a tad down from the "1/4" type mark,
in about 6 minutes of after-run running+hood open.  Voltage afterwards was
a bit above 12v on the gauge.

This was in an enclosed, small(2 car) garage that heated up _very_ quickly
when I turned on the switch.  I imagine things might work better in an open
area where the heat will dissipate and there is likely to be a slight
breeze.

I debated between putting the switch in the engine compartment and under
the dash, right where the footlight is.  I went with the compartent since I
couldn't see an easy way to get there and I realized that most of the time
I would use the switch would be when I wanted to do work on the car+hood
would be open anyway.

If I wanted to get fancy, I could make up a circuit with a 555 timer and a
solid-state relay to have the fan run for a set(well, adjustable) period of
time.  One could even use a thermistor to do it.  You could also use a
injector fan switch from a 5k to turn on the after-run.


Also, you could, during the track run, leave the A/C on, but pull the relay
for the clutch.  A sneaky way of getting the Stage 1 fan to run but not the
compressor.

Brett

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Brett Dikeman
brett@pdikeman.ne.mediaone.net
~)-|
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Ita, scio hunc 'sig file' veterem fieri.
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