Originally Posted by
RWTD
Deleting the (Charge Motion Control Valves, aka IMRC - Intake Manifold Runner Controls) can/give you more power above the normal CMCV opening, especially in the higher rpm range, as they do pose a slight restriction, but you will lose some low end power below approx. 2k (nothing really major, and a gear change in the future would keep you from even noticing). There isn't anything "funky" it does to the car, provided you make the proper adjustments in the tune. Also, anytime you add in a PDB (Positive Displacement Blower), they are automatically deleted in those kits anyway.
With that being said, you MUST follow the detailed instructions below when deleting them on the S197 3V Mustangs, as well as any 3V 5.4 truck. The reason for this is when you set the "IMRC Switch" to "Disabled" the pcm thinks they are closed at all times, and you obviously want the "Open" table values to be used.
How To: CMCV/IMRC Deletion & Tune Modification Information
1: Under Engine, Airflow, General Airflow, change "IMRC Switch" to "Disabled".
2: Under Engine, Airflow, General Airflow, copy the "Angle (IMRC Open) Torque" table to the "Angle (IMRC Closed) Torque" table.
3: Under Engine, Airflow, General Airflow, copy the "Angle (IMRC Open) Load" table to "Angle (IMRC Closed) Load" table
4: Under Engine, Airflow, General Airflow, copy the "Load with failed MAF (IMRC Open)" table to the "Load with failed MAF" table.
5: Under Engine, Airflow, General Airflow, copy the "MAP at Zero Airmass (Open)" table to the "MAP at Zero Airmass (Closed)" table.
6: Under Engine, Airflow, General Airflow, copy the "MAP per Airmass (Open)" table to the "MAP per Airmass (Close)" table.
7: Under Engine, Spark Control, Spark Advance, copy the "Base (IMRC Open)" table to the "Base (IMRC Closed)" table.
8: Under Engine, Spark Control, Spark Advance, copy the "Base MBT (IMRC Open)" table to the "Base MBT (IMRC Closed)" table.
9: Under Engine, Spark Control, Spark Advance, add (+) the "Base MBT" table under IMRC Spark to the "MBT Spark" table under Main Spark. To do this, copy this entire table by clicking on the top left cell, right click copy, then do a "Paste Special, Add" into the correct table. Once done, zero out the "Base MBT" table.
10: Under Engine, Spark Control, Spark Advance, add (+) the "Base" table under IMRC Spark to the "Borderline Knock" table under Main Spark. To do this, copy this entire table by clicking on the top left cell, right click copy, then do a "Paste Special, Add" into the correct table. Once done, zero out the "Base" table.
Edit: FYI, I just found a problem with the software. It doesn't allow negative values on the tables listed for #7 and #8 above. However, I don't think any of the negative values are different between the two tables, just the positives ones only (just glancing at them, tho). Regardless, I'll send in a bug report to support.
I hope this helps!