94-95 Mustangs Tuning Spark

From Mustang-Tech

Contents

Overview

The EEC expects the base timing to be at 10 degrees before top dead center

spark_MBT_table - Values the factory believes will make the most power. I set the values in this table to mimic my spark_altitude_table

spark_altitude_table - At higher altitudes you need more spark advance, set this table to mimic your spark_base_table +2.

spark_base_table - This is the table you will do most of your TwEECing

spark_bdln_table - This table is the maximum allowed spark, regardless of what you enter in the other tables or multipliers. I set this table to all 55's the highest number that CalEdit will accept.

Shift Retard (really a spark retard)

The EEC scalar spark_min_for_tip-in_retard defaults to putting your timing at 5 degrees BTDC on shifts.

Set this scalar to your maximum spark advance (26 in J4J1, higher in others) to disable it.

Spark Calculation

Below is a description of how the base and borderline spark values (94+) are calculated, along with all the adders. While putting this together I realized that I really need to add some new functions to all of the .dat files, and rename some existing ones. I'd like you guys to tell me if this is ok. What I'm thinking of doing is just renaming the necessary functions, and adding the new ones to the end of the .dat file. That way you'll be able to read in a .cal file saved with the current .dat file, and you'll see any functions you've updated with an X, even if the name changes. I'm trying to make this a painless process, so input is welcome. I think you'll see why I need to rename some stuff for clarity.

BASE SPARK

BASESPARK = spark_base_table * spark_bp_bias + spark_altitude_table * (1 - spark_bp_bias) + spark_base_retard_ect_multiplier + spark_base_adder_egr * EGR % + spark_base_adder_a/f_ratio + imrc_spark_ramp_mult * imrc_spark_add_base_spark

BORDERLINE SPARK

BODERLINESPARK = spark_bdln_table + spark_bdln_retard_ect_multiplier * spark_bdln_retard_for_ect + spark_bdln_retard_act_multiplier * spark_bdln_retard_for_act + spark_bdln_adder_a/f_ratio + spark_bdln_temp_load_increase * spark_lugging_timer + spark_bdln_adder_egr * EGR % + spark_bdln_adder_a/f_ratio + spark_bdln_octane_plug_retard + imrc_spark_ramp_mult * imrc_spark_add_bdln_spark


Adder (retard) for ECT needs clarification

Base spark adds "spark_base_retard_ect_multiplier" to everything else and Borderline spark adds "spark_bdln_retard_ect_multiplier * spark_bdln_retard_for_ect" to everything else The Borderline multiplier table and the ect function on GUI make sense together since the multiplier is x=rpm, y=load and the retard_for_ect is a function with advance (negative in table) vs ECT Spark_base_retard_ect_multiplier table is not really a multiplier, it is an adder table of spark added (or removed) relative to load and ECT. The Shiftmaster software calls this SPARK_ADDER_VS_ECT #...(Deg BTDC) (Load vs ECT) That table seems ok. The GUI table may have an incorrect x_normalizer showing timing added/removed relative to load and RPM, not load and ECT.