can someone please explain to me what this is? i was reading and came across a car with a blow through mass air. i was just wondering what the purpose of it is and what it does?

 

It puts the MAF sensor after the turbo and BOV .Most people want to do it so that they can run a 100% atmospheric BOV without the problems that can occur with them.It would be easier in my opinion to just switch to a speed density system.

 

ok i understand but what is a speed density system? you mean like stand alone

 

There are two basic types of air flow measurement used in vehicles with OEM electronic fuel injection - Mass Air Flow (MAF), which Subaru uses, and Manifold Absolute Pressure (or MAP), otherwise known as the speed density system.

Here are a couple of links that may help explain it better, or else Google using keywords like 'map vs maf'.

http://www.carcraft.com/techarticles...fi/index3.html

http://www.cis.udel.edu/~davis/z28/ecm_swap_730/

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