Dynamic Air Tuning

1. I have become aware of two primary ways to tune (E38 GM): a. MAF and VVE separately and b. Using dynamic air and doing them simultaneously. What is the thought on the Dynamic air method of tuning?

2. Filtering data seems to be a critical aspect in removing transient data before updating a tune file. What filter formulas is anyone using for CL and PE data? The ones I have collected seem to eliminate a lot of data, and it seems unlikely its all transient.

3. I have changed my cam from a stock GM cam to a Cam Motion stage 2. In the tune file there is a spark table GM (ECM 12660) that is the theoretical spark advance that delivers the max torque. How critical is it to update this table and how does one do it?

4. I use an AEM tail pipe WB sniffer with an extension that goes up the tailpipe as far as I can get it (~8inches). I recognize it may introduce some error, but how much and do I need to compensate for it?

Each of these questions may be a topic on their own, but I was hoping to keep them together so I can maintain the "bigger picture" as I get my rebuild into the car and started.

All of the tuners that I personally know, who deal with the E38 (including myself) do the MAF/VVE method. I never learned the dynamic airflow system. Doing MAF and VVE separately feels easier to me, as it lets me eliminate variables and focus on 1 thing at a time. It’s not the most efficient way to tune, but it works.

As I understand it, the ECU always defers to the MAF for data anyway and uses dynamic air to makes its final decisions on fuel. If we don’t consider dynamic air, the trim corrections to the calibration tables are not as perfect as they can be. I took a look at dynamic air during a scan and based on the premise the ECU final decisions are based on dynamic air, there is enough of an error correction not being used to update the calibration that it makes sense to consider it.

its a topic the Academy perhaps can take on and see if it is the next evolution in tuning.