Blow through MAFS

[AadosX]

Hrmm I was thinking about something tonight and have a few questions that I'm sure many of you can answer. I thought about putting the MAFS on the coldpipe right before the throttle body, instead of after the intake/before the turbo. This would allow you to use a BOV without circulating it, as long as it's before the MAFS on the coldpipe, or on the hotpipe. This way it would read the air after it's let off, and the car wouldn't have stumbling/stalling problems (in my theory). I'm wondering first of all if this would work. Secondly though, this brought up a general physics question of mine. The turbo wheel pulls air through the intake then into the hot pipe/ic/cold pipe, meanwhile holding the same pressure (or close to it). So would the air sucked through the intake be moving with the same pressure/speed/etc. as the air going through the hot/ic/cold pipes? I just started to think about it when thinking of damaging the MAFS. Lastly, I would assume the IC piping would have to be the same diameter as the MAFS, right?



Thanks,
John

[blu808]

I have thought about this aswell. I just didnt want to risk blowing up a good maf. I dont think the pressure would affect it, however sinse it is a hot wire type maf, the air temp variation might effect things. I just came to the conclusion that since no one uses it, it is probibly not the way to go. It would be fun though. Can you inagine how good the turbo would sound?

[NZO]

:confused: Do a search this is a somewhat common setup.

[Mr. Spool]

Sure is, I use it and love it. The fact that people dont use it has nothing to do with it being a good idea or not. It also gives you better response and a great idle, I wouldnt want to use anything else.

[tastyratz]

before I decided to go map sensor I was thinking of running a blow through maf. it seemed like a really good idea although I did somewhat have the same concerns you mentioned with the whole concept of a maf sensor working by hot wire and the thing being blasted by hot boosted air...

[Jeff240sx]

z32 maf + 15psi + blow through = $100 worth of plastic chips.
cobra maf + 15psi + blow through = Awesome... but.
But, you'd need IC piping that goes 3.5" to 3" or something. I know you can use silicon reducers, but then you massively disrupt airflow.
Maybe the grenatelli maf that a few people have run is a 3"-3" maf, rather than the conical joke a '93 cobra maf is.
-Jeff

[RBS14]

one common problem with blow through setups is contaminating the sensor element itself with oil. Most all turbos lose a little bit of oil into the compressor housing which then gets pushed through your Piping/IC and into your intake mani. It's a very small amount, but that's all it takes to cover your sensor element and therefore ruin your maf. I've heard of people doing blow through setups and going through 5+ maf's.

why is it so hard for people to recirc their bov's? [/rhetorical question]

[Mr. Spool]

get a good turbo and check your maf, you should be fine, I have no oil in any of my lines and never have. i have blown several turbos and none of them mess up the maf or send oil through the line.