Adam---A/F monitors is one of my favorite subjects, having installed the
K&N kit one in my own '73 about seven years ago. Conversations with
Nelson about ths prompted him to build
a better one, to suit the TR6 with a double downpipe.
Ideally, there should be one 02 sensor for each (carburetor's) exhaust
output, with each one reporting to its own A/F monitor. It's also
possible to use just one monitor, with a handy toggle switch to go back
and forth to the exhaust side you want to isolate.
One can also use just one 02 sensor, if placed in the exhaust stream
that sees all of the exhaust. Doing so will make the tuner have to
initially "guess" as to which carburetor needs tuned, if the LED reading
is out of the expected range.
i.e. If one carb is lean and the other is rich, the sensor could
conceivably report that the mixture is "ideal". I don't know how FI
engines deal with this, if, say, one or more injectors was
malfunctioning. (It is said that some car makers are trying one sensor
per exhaust pipe).
A/F monitors could be considered window dressing for a stock, or mildly
tuned motor. Stock carburetors can be equally tuned to compensate for
such setups, using traditional methods. Those using different
carburetors, or different needles, along with other major changes,
benefit most when installing a system that tells us what's going on. No
seat- of -the-pants here! These systems report instantly thru a series
of LED's, to changes in the A/F ratio, thruout the rpm band.
My monitor is in the dash, replacing the spot once occupied by the
driver's side eyeball vent. (See p.240 of Kastner's new book) No holes
need be made in the dash.
Chris---I don't know if a SMITHS analogue gauge could be adapted, for
more of a factory look that you are after. There are monitor faces that
look very similar to the TR guages, if you want to place it n the dash.
Combine two other guages as one?
As Kai reported, welding or brazing in the bung that the 02 sensor
screws into is easier done in a steel exhaust pipe. About half-way down,
and slightly below the level of the starter motor is a good place. Face
the sensor(s) to clear surrounding hardware.
To keep the sensor hot enough for accurate reporting, I found that
wrapping this pipe six inches on both sides of the sensor with an
aluminized "header wrap" works well. Long periods of idling the motor no
longer causes a drop in sensitivity in the sensor. A thee-wire sensor
can be used, but they're really not necessary if placed as descrbed
above.
Tick-tock!
For more info, there are excellent web sites on 02 sensors.
Dick Taylor
Adam wrote:
I'm thinking about installing an Air/Fuel sensor in my TR6. should I
put the O2 sensor on the exhaust manifold or on the exhaust pipe? Should
I try to install two or would one suffice?
Thanks!
Adam
73 TR6
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