Post turbo MAF vs Pre turbo MAF

It has come to my attention that some cars leave the MAF sensor pre turbo and some have it post turbo (on charge pipe near TB) so my question is which is the proper way and why?

It usually depends on the setup and what you're trying to achieve. Most factory turbo cars have the MAF before the turbo (draw-through) because the airflow is more stable, and it’s easier for the ECU to calculate fuel and load. The sensor also stays cooler and isn’t affected by boost pressure.

Some aftermarket or high-performance setups move the MAF after the turbo (blow-through), usually in the charge pipe before the throttle body. This helps if you’re running a vent-to-atmosphere BOV since the ECU won’t be confused by lost air. The downside is that airflow can be more turbulent, and the sensor is exposed to higher temps.

For most setups, keeping the MAF pre-turbo is the safest and most reliable option, unless there’s a specific reason to switch to blow-through.

Sounds adequate, my main concern is that on my particular set up Jim Wolf tec Twin Turbo kit for the vq35de has it draw trough but my car felt very sluggish on acceleration so I changed it to blow through and it immediately became snappy. So I thought Mabe sensor was reading completely different but with your explanation it’s seems this shouldn’t really affect as much as it did…

Here’s a pic of the oem setup

Yeah, I get what you’re saying. In theory, just changing MAF placement shouldn’t make that big of a difference, but in practice, it definitely can. Sounds like in draw-through, your sensor might have been getting turbulence, reading inconsistently, or maybe even dealing with a small leak somewhere.

Switching to blow-through probably gave it a cleaner, more stable reading, which is why the car feels snappier now. Did you have to mess with tuning after the swap, or did it just run better right away? If it was an instant improvement, that kinda confirms the draw-through setup wasn’t ideal for your twin-turbo kit.

Might be worth checking logs if you haven’t already, just to see how your fuel trims and AFRs changed.