Thread: MSD Success
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fredmeister fredmeister is offline
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Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,217
Garage
I have been following this thread and finally bought the 6AL-2 unit as part of the winter rebuild.
I have not run the timing curves I am presenting here, but wanted to offer them up for opinions by you guys. I developed them trying to emulate the stock ignition curves from the factory manuals. I used the 78 California dizzy as a guideline since this is the unit installed in my 79 930.
My engine is a 3.4 with SC cams and 7.5 to 1 compression. I am limiting the boost to 0.9 bar currently and have a B&B intercooler along with headers so that I can take advantage of the extra intake charge cooling and lower boost thresholds to improve the engine response.
I did adjust the boost retard curves to take advantage of the 3bar MAP sensor and run some more timing advance under vacuum conditions to improve the low load fuel mileage. Then I start retarding under boost to finish at 20 degrees BTDC at 0.9 bar.
In case you cannot read the comment window in the image....total timing advance is set at 34 degrees BTDC. At no vacuum it retards 5 degrees to 29 BTDC like stock Euro timing or US 26 plus 3 degrees tolerance. Total boost retards 11 degrees at 1bar.
Just looking to get some comments on these curves and add some insight to this excellent thread.

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1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"

Last edited by fredmeister; 11-26-2012 at 12:02 PM..
Old 11-25-2012, 02:01 PM
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