[jpnovak]

These curves are most helpful. Maybe it has to do with the large jump in Fuel trim at WOT between 2000 and 2480. Could it be compensation for a low-speed acceleration event based upon timing and not fuel enrichment.

I am sure that some will not share their information and I understand the reason why but I will ask the question anyway. AFtermarket tuning chips make changes to the fuel and ignition maps. In what areas are the factory specifications too conservative? Where are the areas that need improvement and how much can you improve safely? These can be approximations without specific numbers. One might say that after peak torque the engine is too lean(or rich) or that the timing in this area is too advanced for peak output. I realize that once the fuel trim is changed that timing should be altered to take advantage of the increased (or decreased) AFR.

I am currently running a twin-plug distributor. I run 12 deg at 1000 and max of 27 coming on at 4000. This is a converted SC distributor. It runs well but I think I can gain some smoothness for more lean cruise.

I have been reading the book "Internal Combustion Engine Fundamentals" by John B Heywood. There is some very good information regarding spark curves in there. I will summarize once I finish digesting.

Jamie