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Magnum engine and timing

Detective D

Well-Known Member
Local time
8:39 AM
Mar 3, 2021
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Recently I decided based on observation that like most old V8's, my 318 Magnum in the Dakota prefers not to consume ethanol. The exhaust is smoother, it responds better, runs better period.
I can only basically get 91 or 93 octane with no ethanol in WI. probably because there are only two pipelines from the refinery coming up here and a major ethanol plant is in the middle of the state.

Anyway, it got me to thinking.

If I commit to premium 91, it may open the door to being able to reset the timing to take advantage. However, I am not versed in the 90's Dodge truck ECU's to know how sensitive they are to fuel octane and/or if they have adjustable timing tables based on sensor feedback like some other brands and newer vehicles, or if like Ferd back then they added timing at WOT or not.

has anyone here, using factory ECU, messed with timing on their 318 or 360 magnums? I am sure plenty here owned a 2nd gen Ram with either or. I had a 2001 with the 5.9 but never went that far, it didn't seem to mind the ethanol as much, although that was some years ago and admittedly the fuel quality has declined over time in general.
I don't want to buy a tuner chip. Looking to do this on the el-cheapo.
I can say, the ecu is crude enough when I took the rear O2 and zip tied it to the frame rail so I could cut the plugged up cat off, the ecu found it to be just fine. Mine is a 98. I know as close as 99 they started the 4 O2 sensor set up where they are on both sides of a cat off of both sides of the engine. So I may have the last of the old school where the O2 is only used on the front end to monitor A/F ratio for the ecu. I just don't know if there are knock sensors or other data the ecu uses for timing or fuel control.

Any experience on this would be helpful.
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