Originally Posted by lazzer408
Joe, does anyone here know someone at Bell or FM that might have that information? I think it was Corky (Bell), Justin (FM), or Henry from AEM that told me the Eclipse curve was very close to the Miata curve fwiw. If anyone is interested, here's AEM's ignition map from the basecal file they provide with the EMS.
Nice find- that's a very cool chart. Which engine is that for, exactly?
The closest data I've seen from FM is the chart in the documentation for the non-piggyback Link, which gives ignition advance for RPM vs. KPa. I don't know where they got that data from however- it might have been the result of dyno sessions rather than observing the stock ECU. And I doubt that Bell has anything like this available since the XCEDE is just a piggyback (although in fairness I've never actually asked).
I believe that someone once was on a project to reverse-engineer the ROM section of a stock 1.6 ECU, however I don't recall seeing any actual data come out of that effort.
The biggest point of confusion for me has always been that the stock ignition curve is based off a "load" parameter, which is a pretty arbitrary concept given that AFM voltage varies with RPM for a given manifold pressure.
If someone had a lot of time on their hands, it would actually not be too difficult to slap an EMU onto a stock engine and datalog the whole thing. That's basically what I did to reverse-engineer the AFM voltage vs. MAP/RPM table when I did the writeup on AFM removal. It took about two weeks' worth of "average" driving, plus another couple of evenings to crunch all the numbers and build the table.
Unfortunately I do not have my CAS wires connected to the EMU so I've never been able to chart actual ignition advance. Someday I may go back into the dash and put those wires in, but the way I've got my EMU mounted it's a real trial to get to.