Originally Posted by AllEuro

As I understand it, they are two different ways of doing the same thing. The MAF sensor is essentially an exposed metal wire that extends down the center of a ~3in plastic tube as part of the intake tract. As air enters the intake tract, it passes across this wire. I forgot the exact details (anyone can feel free to fill in the missing parts), but the act of the air passing across the wire, will create a certain voltage that is by nature associated with a specific volume of air that will enter the motor. It is by knowing this volume of air, that the ECU knows how much fuel to add. So when the air passes through the MAF, it is now referred to as "metered" air. Any leak in the intake system after the air passes the maf will cause the motor to run poorly as less air than was measured will enter the motor, but the ECU won't know this, and a rich running condition will start.

With regard to boost, neither the ECU nor the MAF "know" what a turbo is, all they know is air and fuel--it all comes down to maps in the ECU that correspond to certain volumes of air with fuel in relation to RPM, throttle position, etc. So technically, yes, you can run boost on a MAF based system. However, most MAF systems are set to read only a certain amount of air volume after which it will not register additional air flow and then you have a very lean situation. My VW has this same type of system and the VR6 (6-cyl narrow angle VW motor) guys have been through this stuff for quite a while. It looks like the NA crossfire has the same 5v limit as the maf for the VR6. What this means is that you can program the ECU to read boost, but there is a limit. It is believed by many that 10 psi is about the max the stock MAF on a VR6 will handle. This may or may not hold true on a crossfire. What this essentially means is that on cars with 10+ psi, the volume of air being sucked past the MAF will effectively create a MAF voltage that is unreadable by th ecu. The way to get around this is to create a large MAF housing (the plastic tube that contains the MAF wire) which will serve to functionally slow down the velocity of air.

IMO, this should be TVTs next project. It seems like they know the software, which is by far, the hardest part of all of this. The hardware is the easy part, comparatively speaking. I'd love to see a NA crossfire with a rotrex centrigual charger like the BMW guys used. The self contained design of the charger lubrication system means you won't have to tap the oil pan. I believe Procharger also has a similar setup on their superchargers.



Now the MAP stuff I am not familiar with, so if any of the MAP guys could chime in, that would be great. All of my experience is with MAF-based setups. Though I do recall reading that for forced induction that MAP systems are easier to work with when it comes to boost.