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trond trond is offline
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Join Date: May 2008
Location: Stavanger, Norway
Posts: 936
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ignition advance SC with MS

I have been a very happy Megasquirt user since my car was converted to tbitz in 2011 in one busy afternoon at Jamie Novaks in Austin (hi Jamie and thanks again !)
My distributor was worn and I since went distributorless with MSII and EDIS ignition and the system has worked flawless from day one. Not one day of downtime in 5 years and 32000 miles !

While fuelling is easy to get right (Tunerstudio and wideband lamda), even on the street, ignition is another thing. I tried on a chassis dyno, but prior to installing TPS it just was not easy with map only.

So I have been experimenting with ignition maps on the road which obviously is not to be recommended.....

I am lucky enough to have a friend with the exact same engine in his car(all stock CIS and ignition and all). Driving his car I always found his car to be quicker than mine. Seat of the pants quicker that is. Sweeter engine note and rev happy, as opposed to mine.... With my car I always thought 'this car is not really very fast at all', while with his car I always wondered how could a mere 3 liter stock car be so good...

Given that fuelling is hard to get wrong with MS and wideband, I came to the conclusion that ignition is the only real difference. And the significant difference was he most likely had less advance than I. So I started reducing ignition advance and found to my surprise that the engine seems happier with less advance. I am now down from 32 degrees, to 26 degrees and finally a few days ago 21 degrees at WOT. Which is the best setting until now. I am 'all in' from 2000 rpms and more or less 20/21 all the way to stock redline. I am aware this is not by the book but I just wanted to check it out. At cruise I still run around 40 degrees which seems to work fine and good fuel economy, but the slightly hard engine note from before at higher loads is all about gone ! And the engine is without any doubt more revhappy. Seat of pants for what its worth is positive. I am aware all of this is not quantified in any way and I would be be very cautious using my anecdote for anything. See it more an question to the forum; could it be true or not that the 3 liter 9.3 CR likes significantly less ignition advance than what is commonly referred to on the web ? Or do I have something upside/down ?
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80SC (ex California)

Last edited by trond; 01-26-2017 at 12:51 PM..
Old 01-26-2017, 12:37 PM
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