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MAC-11 and MAC-14 Timing Maps


Things are getting interesting during my search for more boost on my 89 200TQ.

With some hints from RDH I think I located the timing maps (Premium and Regular fuel)
 in the  two different EPROMs for the MAC-11 and the MAC-14 ECU's. 
That's the good news.

This past weekend after receiving the "the Data"that  RDH sent to me on his 
MAC-02 ECU I de-soldered the EPROM's from the spare ECU computers I had from a 
86 5000CSTQ (MAC-11) and from a 89 200TQ (MAC-14). I downloaded the data into
a file and then using some of RDH's clues I was able to locate the maps. 

How do I know  I found them? Well, when looking for the timing maps in the MAC-11
EPROM, I compared the timing map that came from the Audi publication booklet
"1986 Model Change Information". The booklet has a nice timing map with actual 
values for the timing advance versus the engine RPM and the variance with engine load
 (From high boost to vacuum) . I took the timing values out of the 16X16 matrix
that I thought "might" be the timing map and charted them against this actual map.
 They matched exactly!!!!!

The MAC-11 has the most agressive timing at the highest boost timing location, 
with the MAC-02  having the least aggressive. This is not too surprising given the
 MAC-02 has no knock sensor, and the MAC-14 engine has the higher compression.
 At 3000 RPM the MAC-11 (Premium map) shows about 22 degrees advance, 
the MAC-14 shows about 19 degrees advance, and the MAC-02 shows a little less
at 18 degrees. I need to verify the actual timing values with some vehicle
testing and then changing one of the values in the EPROM.

The bad news is that now I am consumed by this "project" and must find the boost 
maps/overboost shutoff location, rev limiter etc. The rest of the map locations for these
values will likely be MUCH harder to locate. What have I got my self into!

More info to come................soon I hope. 
Scott M.