Experienced Haltech but New to UpRev

xsnapshot

Half mafing is where you take any tables that are referenced to load (where load is derived from the MAFv values and an equation, where calculated load = (g/s*60)/RPM) and then half those values. That way when your hitting a load of 2, its actually a load of 4 and your just tricking the ECU into being able to account for more airflow. You loose resolution doing this, but its better than just plugging in a really rich value in the last cell for open loop fueling, and hoping that it is rich enough to account for the air past the 268 g/s limit so that the AFR is right. As you can imagine, in that case, the AFR would swing rich, then back lean again.

So as an example, all the loads in the ignition advance table, and the fueling are halved, and the injector scalar is halved, and any other table that references the MAFv is halved. You don't have to halve it, you could say, use a value of 75% or something. But the thing you have to remember is when you data log, the values will be different. Its a tricky thing to wrap your mind around, and I honestly wouldn't recommended it without knowing for sure that other tables are not referencing the MAF to apply compensations.

The thing about g/s is it doesn't necessarily mean you can predict the MAFv. There should be a table that is called a mass airflow sensor calibration (or something similar) where a voltage range (1-5v) is correlated with the appropriate g/s for that voltage. These are the values you would change to account for a CAI bringing in different g/s than the stock intake, for a similar voltage.

I'm sure the Subaru MAF is different. However ours don't read past something like 4.76 volts. My 300 g/s is hit at that voltage, however I'm only at like 4.6x volts.