Some of the Mopar ECU will retard the ignition timing a little (1 to 2 degrees per 1000 RPM above 5000 RPM :scope) above 5000 RPM
when I first started paying attention to drag race tuning a lot of the faster racers had a switch to turn off one set of points to retard the ignition timing in high gear
It seems like some of the street and strip MSD boxes would also, maybe not as i never used them
ALL ignition boxes retard with RPM. All of them. The best box I’ve tested for that is a early 1980’s DC Gold Box. It retards 1 degree in 10,000 RPM. I think it took 8,000 RPM to get that.
I just tested a well know box for street stuff and it retards 6 or 7 degrees (I can’t remember if that box was 6 or 7 because I tested 5 boxes that day and that one was one of the boxes that had the most retard) and IIRC started retarding at about 4,000 or so and kept retarding to 8,000.
Are we talking MSD boxes etc. or Mopar ECUs / Ignition Modules that like came from the factory 1972 and later ?
I literally have tested a handful on my 71 Superbee 383/432 Stroker , and none of these Chinese knockoffs , fake transistor ECUs , work well over 5,000 RPMs - Like mentioned a few start failing at 4,000 RPMs
Really had me digging deep over a few summers
My 1990s Mopar Performance Chrome ECU was the best unit , until that failed a few years back
Now I have some brand new never mounted Standard LX101s from 1986 and 1987 that where made in the USA I need to try out
I remember reading this some years back
https://www.hotrod.com/articles/mopp-1211-3-2-1-ignition-box/
