Thread: Ignition Timing
View Single Post
billjam billjam is offline
Certified User
billjam's Avatar
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,001
This subject has me puzzled as well.
What timing is best to use if your motor isn't strictly US or Euro?

For example, I have an 86 US car (930/68) and I have deleted all the emissions control stuff (smog pump, O2 sensor, cat, etc.) and most of the cold start gizmos. It has SC cams and the dizzy with boost and vacuum ports.

In the Porsche manual (page 28-2b) it gives the following values:
Europe, ROW: 29 degrees before TDC at 4000 rpm (with vacuum disconnected)
USA: 10 +/- 2 degrees after TDC at 1000 rpm
California, Japan: 5 +/- 2 degrees after TDC at 1000 rpm

I have only recently put this engine back together after a major rebuild. I've played with a few settings and have settled on about 7 or 8 degrees ATDC at 1000 rpm and it seems to perform OK, but I don't know if this is the optimum.


Can anyone explain why the Europe and ROW models are timed at 4000 rpm and not at idle?
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ...
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 02-09-2009, 11:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)