thanks for the sensor info

[auditude at neta.com]

Hey all,

Thanks for the information regarding timing sensors and pins and
such.  I think I actually understand now what the sensors do in a
MAC11.

I've sent an email to my tech support guy, describing how the
stock ignition sensors work, and asking for confirmation that the
LinkPlus ecu can be configured to use them.

I have decided that I will try to use the crank as my reference for
ignition timing.  As far as I know, Audi has always used the crank
as a reference for turbo motors, and the cam driven ignitions are
only for the non turbo motors.  I don't want to take a step
"backwards" in technology, especially since I will be trying to push
the boost and ignition timing as far as I can.  I don't want the slop
in the timing belt and distributor gear (if I use the 4kq one) to affect
my ignition timing accuracy.

(Of course this is not an issue for those using 034EFI, since the
trigger is used for fuel and not for ignition, not to mention if the hall
sensor pickup is off the cam gear, then the distributor lash is
removed  from the equation.)

If I'm forced to use "only" the cam as my ignition timing reference,
then I will just use the stock 4kq distributor/hall sensor.  This is if I
not only cannot use the stock sensors/timing pins/single window
hall sensor, but also cannot fabricate my own crank driven setup
that will work with the new ecu.

So in simplified terms, my new ecu will have to see the flywheel
ignition timing reference pin go by, wait 62 degrees of rotation (or
whatever is appropriate for the amount of advance desired) by
counting teeth (2.667x62=~165 teeth), check to see if the
distributor is sending it's signal to confirm cylinder number one is
on the compression TDC and not the exhaust TDC, and then fire its
spark.  After that, it needs to count teeth and fire each successive
cylinder 27 teeth later (135/5=27).  Does that sound right?

I do have one other question.  What kind of power do the hall
sensors need, if any?  Are they active or passive (do they require a
voltage, or do they produce a voltage)?

Also, I'm not even sure if the two flywheel sensors are considered
hall sensors, are they?  I've been referring to all three relevant
sensors are hall sensors, but I typically only see the distributor one
being referred to as such.

This is crazy stuff, but it's interesting!

Later!

Ken