Racintweek

99.9% of all OEM turbo cars have the MAF before teh turbo. but they also use recirc valves instead of BOV so the pressure/air thats released gets accounted for.

baldur

I tend to not run a MAF at all.

HMT-Admin

on a kia turbo project I just did I tried both ways, and the best way for idle and rippers was having the MAF after the turbo. Inline, before the blow off valve.

Toysrme

You can do a MAF/AFM before, or after. It's not going to be a hell of a big difference either way. Whatever makes the piping the easyest is hat you should do.

I do prefer the responce of AFM's after the turbo.

Loserkidwac

Ok, I was gonna look into this too...My mazdaspeed protege, stock GT25 turbo, has the maf before the turbo and the factory bypass recirculates...People have tried to mount venting BOV but when you shift the car will stall out because of the drop in preasure...the turbo would still be spinning and pulling air in but the bypass opens and therefore air going into the engine would be less than the sensor is reading...I believe that is what happens...but by putting the sensor after the turbo, which i believe is called a "blowthrough" setup you can solve this poblem...the only problem that i can see is it is setup from the fatory before and hopefully the ecu makes the proper adjustments knowing it is before the turbo so for it to properly work after the turbo you just need to have a tunable ecu or i guess a afc...