First and foremost, let's make it clear what this page is all about. This page describes an adjustment tool in the ECMLink application that helps to dial in your speed density (SD) VE table based on data collected from a mass airflow sensor. If you do not plan to run speed density mode with your car or you do plan to run SD but do not have a mass airflow sensor installed for dial-in, then this page is completely useless to you and you should ignore it.

If you're not even sure what speed density mode means, then read up on our Speed Density 101 page.

This function basically tries to configure your SD table to produce the same airflow values as your mass airflow sensor. So it stands to reason that you want to make sure your mass airflow sensor is calibrated very well first.

The MAFComp Adjust (CombinedFT) page describes an excellent process for dialing in your mass airflow sensor. Please read through this page carefully and make sure your mass airflow setup is calibrated as well as you can get it before attempting to use the SD VE Adjust (SDRatio) function.

To use this tool, you need to capture some data from your ECU while you drive around on the mass airflow sensor.

Add the following log items to your captured values (F10): SDRatio and MAP sensor

The MAP sensor you want to log here is the one you have already configured in your Manifold pressure (MAP) field on the ECU Input tabs. An example of this is shown here. More details on configuring and installing this sensor can be found on the ECMLink - Speed Density Setup page.

When attempting to initialize this tool, the application will check your ECU Input tab to locate the MAP sensor. It will then attempt to find this sensor in your datalog. Using the image above as an example, you would want to log the GM 3-bar sensor attached to the MDP input in order to use this function.