| Yes you can have both. Doesn't matter if you have the Selin in or not. The neo just plays with the MAF voltage buy manipulating it (if you use it for that purpose). Here's how the whole Selin, MAF, CFM lookup table thing works... A two MAF sensor example.
- The CFM to voltage output of the MAF is known. The specs can be obtained from the manufacturer or by doing your own flow test or by reading the CFM table in the eprom data.
- Take the MAF voltage as read from each MAF.
- Using the CFM to MAF voltage table, find the CFM of each MAF by the voltage value.
- Average or add the two CFMs.
- From that CFM, use the CFM to MAF voltage table again to find the voltage of the new CFM.
- Send that voltage to the ECU.
- The ECU then uses that voltage and compares it to the VQ voltage table.
- The VQ voltage table then tells the ECU which "global" register location it's working on.
- The global register location just happens to have the same name as the current CFM. This is the CFM table and also where you can find the CFM to MAF voltage for the MAF that your car uses.
- For example, if the CFM is 275 then the register is CFM register table 0275. A CFM of 300 would be register location 0300 in the CFM table and so forth all the way up the scale to the max value of the CFM table.
- The rest of the ECU's calculating functions in their given tables stays in sync in the same table location as the current CFM register location. In other words, if the location is "O" in the CFM table like below, then all other tables for their given calculating function will also fall into "O". It all stays in sync as the location of the CFM table changes. XXXX
XXXX
XOXX The neo or a SACF will do the same thing the Selin does. It adds or averages the MAF voltages and sends it to the ECU. There is really nothing different about how they work when using them for that purpose only. The Selin claims to calculate faster and have a more accurate voltage output. It's main benefit is its easier to plug and play. To me, the accuracy of the Selin is irrelevant. The reason is, the voltage output of the MAF (or Selin) is compared to the VQ table to tell the ECU which table location to work with. The voltage values in the VQ table have areas of margin between each voltage on the table. For example, one location on the VQ table is 2 volts. The next higher location is 2.08 volts. So there is a margin of .07 volts to work with. In other words, the MAF voltage output can be between 2 and 2.07 volts and it's still going to put you in the same table location. You can have an inaccuracy of .01 to .07 volts and it doesn't matter. Getting back to your main question, it doesn't matter if the Selin is in line with your neo or not. All your doing by adjusting the MAF voltage output of the neo to the ECU is tricking the ECU into thinking you have more or less air. It does nothing to the function of the MAF or Selin. By decreasing the MAF voltage you'll cause the engine to run more lean because it thinks it has less air with the smaller voltage input. In reality you have more air so the less fuel being given combined with the more air makes it run lean. This will also advance your timing. Increasing it will run rich and retard your timing. With all this said, it "is" known that if you advance your timing you'll produce more power. But you can only do this so much and gain only so much power.
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23:11:06 06/28/16
