'88 5kcstq/MC-1/MAC11 timing reference pin location?

[auditude at neta.com]

Hi all,

I got a call from the place I'm getting my LinkPlus engine
management system from, and he's requesting information about
the stock timing reference pin location on the flywheel of my car.  If
I can avoid having to add five pins to the cam gear, and use the
stock (hall?) sensors at the flywheel, I'd prefer that.  I'm told that if I
provide the details of the stock system to the manufacturer of the
ECU, they can tailor it to use the stock sensors.

I'm going to do some research in the archives to see what I can
find, but I thought I'd post this to see if I get any responses.

I know that the stock setup uses two sensors, one for rpm by
counting teeth, and the other for timing reference by the single pin
on the "back" (engine side) of the flywheel.  The location of that
reference pin was probably told to me back when I was getting my
flywheels turned, but I wasn't this far along in my thought process
back then and didn't note it.

What I need to know is how many teeth there are, and where that
pin is in relation to TDC for the first cylinder in the firing order. (what
does that mean, anyway?)  Is the first cylinder the one at the front,
and I want to use that for TDC, or is a different one the first to fire?
I know the firing order was just posted somewhere, either here or at
that other Audi site that usually has a lot of A4's.  I think it's on the
casting too, but I'm sitting here typing anyway...

Everything in the documentation for the LinkPlus seems to indicate
that you absolutely need a cam trigger, if not both crank and cam
triggers.  IIRC, it's because of the odd cylinders.  Otherwise you
could just mathematically divide the crank signal by two.  But then
again, they are asking, so I'm going to give them the info.  I
suppose if it can count teeth like the MAC11, then it shouldn't be a
problem.

Anyhow, thanks for any info.  It would certainly be pretty cool if
they developed it so that there was a 5 cylinder application that
uses the stock sensors. :-)

Later,

Ken