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fredmeister fredmeister is offline
Smart quod bastardus
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Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,232
Great thread guys.....
I am having similar issues with pinging last nite since I changed from a 0.8bar boost spring to a 1.0bar spring.
My car is a 79 930 with the dual port can, the boost retard is open to atmosphere. Vacuum side is connected as normal.
Checked timing and here is what I have which confuses me:
at idle of 1000rpm..... timing = (neg) 7 degrees BTDC VACUUM PORT CONNECTED
at idle of 1000rpm..... timing = (neg) 29 degrees BTDC VACUUM PORT DISCONNECTED
Honestly I was shocked because I thought that the 29 was aweful high at idle because as I rev to 4000rpm (NOT DONE AS YET, SO CANNOT REPORT RESULTS) I expect the mechanical advance to go even higher.
Now the safe limit from other posts I have read under full boost and high revs indicates 26-28 degrees max timing BTDC......I wonder what it will be when I run it up to 4000rpm with vacuum disconnected.
1) In short, how much more advance does the mechanical advance add by itself?
2) Are my mechanical advance weights frozen at idle to explain the above results so far?
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"
Old 04-10-2008, 02:41 PM
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