Blow threw mass air, so is it good or is it bad? (I searched)

[AN89HATCH]

My question is a blow threw mass Air good or bad?? I did a search, I find some people say it works great, and I find other people that say It does not work at all, so will this work? I plan to run 4-5 psi, with an open bov. Will running the blow threw mass air mess up the mas air flow meter? Would it be better just to go with safc?

[ziggy682]

As long as it is designed to minimize the turbulence of the air going through the MAF, it will work just fine. Everyone has their opinion about it, but I have a blow through setup in my car, and I can tell you from experience it works just fine. Most people just relay information that they've heard without having any experience themselves. If you want to run an open atmosphere BOV, the only way to do it right is with a blow through setup.

I'm not sure why you're asking if it would be better to just go with an SAFC. An SAFC and a blow through MAF don't really have anything to do with each other. If you are running bigger injectors, you will still need something to manage your fuel flow(like an SAFC). Running a draw through, or blow though MAF doesn't affect your need for fuel management. Personally, I'm running 370cc injectors with an SAFC.

[AN89HATCH]

Thanks for teh reply The reason I asked about the safc is because I am just going to use the stock injectors with a fmu, since I am only going to boost 4 psi, I do not need the safc, but I was going to use it to trick the ecu, so I would be able to run an atmospheric bov. I dont really want to go through all the problems of tuning the safc to only run 4 lbs of boost

[Jookmasta]

hey ziggy, could u elaborate on ur blow through setup ?

[Jookmasta]

ok so i also did a little research. the blow through would work best for open BOV b/c the MAF doesnt read the air that the BOV releases due to its mounting so close to the TB? correct me if im wrong

[ziggy682]

My setup goes like this.

Air Filter-->Turbo-->BOV-->Intercooler-->MAF-->Throttle Body

Here you can see the BOV mounted on the hot pipe.



Goes through the intercooler.



Here is the cold pipe with the MAF mounted before the throttle body.

[tapdeznutz]

sweet thankx ziggy that WAS really helpful. thanks for the pictures also. but as for the 370cc injectors with fmu do u need anything else to help with the fuel or could u just get away with it but the car wont run as strong

thankx again

[daniel240]

i ran a pull through type (before turbo) mafs setup for a while and had no problems other than some stalling issues. i switched to a blow through type and it ran fine for a while and fixed the stalling problem, then it started running like sh#t. it would barely run and only go to 2k rpm. after i shut it off and restarted it it ran fine then did it again later. it seems like it runs fine for a while then screws up like when it warms up. however, im pretty sure this is a mafs problem or a bad connection. i got another mafs im going to switch it back to pull through type and see how it runs. then im going to run that one as a blow through type. i really hope it is just the mafs, because i would much rather run a blow through mafs.

[Jookmasta]

so, we mount the bov on the hotpipe. the hotpipe is attached to the turbo, which then goes to the intercooler; the cold pipe comes from the intercooler to the MAF and then another pipe to the TB?

[ziggy682]

Yup, but the BOV can actually be anywhere in the piping. However, if you want to run it open atmosphere, you should put it before the MAF.

[ziggy682]

sweet thankx ziggy that WAS really helpful. thanks for the pictures also. but as for the 370cc injectors with fmu do u need anything else to help with the fuel or could u just get away with it but the car wont run as strong

thankx again

If you're running 370cc injectors and an fmu, you will still need something to tune with. Since stock injectors are 270cc, you will need to retune the ECU, or fool it with an SAFC or something like that. If you try to run 370cc injectors with no fuel management, your car will run super rich. Usually the point of running an fmu is so you can just use the stock injectors, and raise fuel pressure with boost, thereby making them flow more fuel than stock. It's the cheapest way to go, but isn't very accurate, and probably shouldn't be used for anything over about 5psi.

[tapdeznutz]

sweet once again much appreciate the input.

jay