Looking for air/fuel meter

[Mark Boxsell]

> Anyone out there know of a source for an aie/fuel meter other than Motec.
> (they want too much for theirs) I hear there might be some Motec clones
> in Australia.
>
> Maybe this hould be a good project for a group of diy_efi members.
> It looks to me that since Motec uses a 4 wire O2 sensor, they must monitor
> heater current to determine sensor temp and then trim the sensor output
> accordingly. Shouldn't be that dificult once you figure out the trim curve,
> and certainly doesn't justify what they want for these boxes.
>
> I have been tuning Electromotive TECs for about 5 years now and am starting
> to get into Autronic systems a bit also. It has been really dificult setting
> mixtures at full load(esp rotarys & turbos) due to O2 sensor drift with temp.
> It varies with sensor placement, turbo size, advance, etc.
>
> Fred Miranda
>
>

  Fred,
        with all due respect, if (you are using a standard O2 sensor) you
are another 
of the band of silly people that tune using standard O2 sensors. If you are
setting mixtures at full load I sure won't let you near my car.
I know the NTK, Bosch units are expensive but you are wasting you time with
a standard sensor except for tuning around 14.7. You have no idea how rich
you are.
If you get the chance (one day) put a UEGO (NTK) sensor beside the standard
O2 and you will see what I mean. It will scare you !!!!!

In regard to the general discussion on A/F meters. As for people building
their own electronics "good luck". By the way the Motec unit DOES NOT use
heater current to determine the temperature of the sensor.
Everyone underestimates how easy these things are to use. It is not as
simple as hanging an op-amp on the end of the thing.

Yes, there is another manufacturer of wide range sensors (don't worry
everyone it's not me !), the company is called Microtec (Australia). It is
not as fancy as the Motec unit but it sure is cheaper! Fred if you live in
the US contact Gene Berg in California (the VW man) and he should be able to
help you.

         regards to all,

         Mark Boxsell.
         MRB Design
         Sydney  Australia