Dodge IAT/ECT timing retard thresholds??? How does retards work

[GrannySShifting]

How exactly do these work? Noticed the deadbands can be set to a minimum of 32 degrees. So if ECT Part Throttle Red is set at 212, Hot Spark Ref is 203deg, and Cold Spark Ref is 158deg - and the Hot Spark and Cold Spark tables are -4 and +4 degrees respectively... what would timing be doing at 158, 203, 212, 240 degrees???

[fumanchu182]

So lets look at the IAT Hot Spark table (32124). Nothing special here it is RPM on X axis and Aircharge on Y axis. Then the individual cells represent amount of timing to be removed if the criteria is met. What is the criteria that has to be met? Well this is where certain cell values in the tune come into play. Part Throttle Ref IAT (44664) on a Hellcat is set to 113 degrees. The engineers decided that this value means they do not have to add or subtract spark as the temperatures aren't too hot or too cold. This is where the Hot Deadband (32122) value comes into play. On my Hellcat this value is set to 32 degrees. The formula is 113 + 32 = 145. This is the hottest point at which no changes will be made. From 146 to 212 (Hot Spark Ref IAT, 44665) the table will be used to pull timing. It won't be all the timing listed in the cell, the PCM will interpolate what needs to be removed.

Thank you for coming to my Ted Talk.

[GrannySShifting]

So lets look at the IAT Hot Spark table (32124). Nothing special here it is RPM on X axis and Aircharge on Y axis. Then the individual cells represent amount of timing to be removed if the criteria is met. What is the criteria that has to be met? Well this is where certain cell values in the tune come into play. Part Throttle Ref IAT (44664) on a Hellcat is set to 113 degrees. The engineers decided that this value means they do not have to add or subtract spark as the temperatures aren't too hot or too cold. This is where the Hot Deadband (32122) value comes into play. On my Hellcat this value is set to 32 degrees. The formula is 113 + 32 = 145. This is the hottest point at which no changes will be made. From 146 to 212 (Hot Spark Ref IAT, 44665) the table will be used to pull timing. It won't be all the timing listed in the cell, the PCM will interpolate what needs to be removed.

Thank you for coming to my Ted Talk.

Thats about how I figured it at first looking at a hellcat. But deadband is usually terminology for a plus or minus value as in 113 plus or minus 32 degrees, in this case its one directional so 113 to 145 is no change to base. If thats case, cold deadband would be 113-32=81 degrees but Cold Spark Ref Temp is 102 degrees. So timing would be unchanged from base from 81 to 113, then all the sudden at 80 degrees would be the max in the cold table modifier as its past the Cold Spark temp? That doesnt make sense.

A standard Challenger makes a little more sense as Cold is 32, Part is 86 and Hot is 160, and youd have no modifier at 86 plus/minus 32 degrees (=54-118 degrees, then interpolation from 32-54 and 118-160)


They seem to be always set to MAT, what is the IAT selectable for, is it possible to break out a IAT sensor and get it out of the manifold for turbocharged/centrifugal setups so you not measuring heatsoak and getting actual IAT?

[Turbo2gnx]

greetings. so if i change the hot spark to 0 and enable WOT and have it set to 0710 in the enrichment tables would there be any issues i should be concerned with? right now im getting timing pulled from -1 - -10 of false kn. i say false knock because the kn voltage is .58.

[Turbo2gnx]

ok i see ive been blackballed! cool!