Td_d
Commander In Chief
A new set of ECT related tables for both intake and exhaust AVCS has been found on the recent 11/12 Sti models. I've found them in the USDM roms, fairly easy to find them in any other rom.
These tables basically reduce the primary tables by a ratio at lower ECt levels, and mirror the emmissions 'hump' that one finds in the lower load / rpm stock AVCS tables. These should be amended to improve idling and to improve warm up catalyst heating. To quote the defs:
Intake:
This map selects the degree of intake cam advance correction based on engine coolant temperature. The amount of correction is governed by the Intake Cam Advance Angle (ECT Related) Multiplier table. The final AVCS angle formula is: (Intake Cam Advance Angle Cruise (AVCS) * (1 - Map Ratio E42)) + (Intake Cam Advance Angle Non-Cruise (AVCS) * Map Ratio E42) + (Intake Cam Advance Angle (ECT Related) * Multiplier)</description>
Multiplier
This is the multiplier to the Intake Cam Advance Angle (ECT Related) lookup result according to engine coolant temperture. A value of zero negates the affects of the Intake Cam Advance Angle (ECT Related) table.
Exhaust
This map selects the degree of exhaust cam retard correction based on engine coolant temperature. The amount of correction is governed by the Exhaust Cam Retard Angle (ECT Related) Multiplier table. The final AVCS angle formula is: (Exhaust Cam Retard Angle Cruise (AVCS) * (1 - Map Ratio E42)) + (Exhaust Cam Retard Angle Non-Cruise (AVCS) * Map Ratio E42) + (Exhaust Cam Retard Angle (ECT Related) * Multiplier)
Multiplier
This is the multiplier to the IExhaust Cam Retard Angle (ECT Related) lookup result according to engine coolant temperture. A value of zero negates the affects of the Exhaust Cam Retard Angle (ECT Related) table.
Interestingly enough, these also exist in earlier Roms (such as mine, 08), but the intake is only 2x2 and the exhaust 6x7, and are switched off by default. Obviously a practice run.
I'm sure this is all emissions based...
These tables basically reduce the primary tables by a ratio at lower ECt levels, and mirror the emmissions 'hump' that one finds in the lower load / rpm stock AVCS tables. These should be amended to improve idling and to improve warm up catalyst heating. To quote the defs:
Intake:
This map selects the degree of intake cam advance correction based on engine coolant temperature. The amount of correction is governed by the Intake Cam Advance Angle (ECT Related) Multiplier table. The final AVCS angle formula is: (Intake Cam Advance Angle Cruise (AVCS) * (1 - Map Ratio E42)) + (Intake Cam Advance Angle Non-Cruise (AVCS) * Map Ratio E42) + (Intake Cam Advance Angle (ECT Related) * Multiplier)</description>
Multiplier
This is the multiplier to the Intake Cam Advance Angle (ECT Related) lookup result according to engine coolant temperture. A value of zero negates the affects of the Intake Cam Advance Angle (ECT Related) table.
Exhaust
This map selects the degree of exhaust cam retard correction based on engine coolant temperature. The amount of correction is governed by the Exhaust Cam Retard Angle (ECT Related) Multiplier table. The final AVCS angle formula is: (Exhaust Cam Retard Angle Cruise (AVCS) * (1 - Map Ratio E42)) + (Exhaust Cam Retard Angle Non-Cruise (AVCS) * Map Ratio E42) + (Exhaust Cam Retard Angle (ECT Related) * Multiplier)
Multiplier
This is the multiplier to the IExhaust Cam Retard Angle (ECT Related) lookup result according to engine coolant temperture. A value of zero negates the affects of the Exhaust Cam Retard Angle (ECT Related) table.
Interestingly enough, these also exist in earlier Roms (such as mine, 08), but the intake is only 2x2 and the exhaust 6x7, and are switched off by default. Obviously a practice run.
I'm sure this is all emissions based...