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fredmeister fredmeister is offline
Smart quod bastardus
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Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,229
Well did some more testing and this is what I have found:
Timing at 4000rpm with vacuum line attached= 45 degrees BTDC. No engine load.
This is in line with previous findings on my 79 distributor of 22 degrees retard under vacuum and 18 degrees approx of mechanical advance.
Now the boost retard measured under 10-15psi = 10 degrees additional retard.
So all in all I have the following with 7 degrees BTDC timing at idle vacuum line attached:
at 4000rpm under 10-15psi boost = 35 degrees BTDC.
This is the best I can get with my stock (dual port canister) distributor which is in perfect working order.
I am now at a loss on how to get back to anywhere near 29 degrees BTDC at 1.0 bar boost 4000rpm without setting static initial timing to 1 degree BTDC at idle. At these settings the low rpm performance off the line is worse than my old VW beetle.
Anyone running anywhere around 34-35 degree BTDC at 4000rpm on pump premium gas?
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 04-17-2008, 12:01 PM
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