MAF Placement

bloodasp90

JZwhore of JAPAN
Nov 9, 2007
529
0
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on the river
ok, so ive been seeing alot of Force induction cars running around (JAPAN) that use MAF senors still, but they have relocated them after the turbo's but just before the throttle body, dose anyone have any kinda idea how this might affect a 7M, even if its possable?

The only thing i can really think of is that its accualy metering the true air that is going into the motor and not into the turbo? But would it distory the sensor once you let off the throttle and the pressure wave hit it?

Its just a idea ive been throwing around for quite some time, and yes, ive searched it, but i really couldnt find if it has good ups or downs.

thanks guys
 

MKIIINA

Destroyer of Turbos
Mar 30, 2005
1,825
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Plano, TX
if you mean the AFM yes it is possible but not recommended. the Kv sensor doesnt "see" pressure but measures the air flowing across it, a map will do pressure. add to it that the afm housing is a defined known space, if you change the size of the pipe its installed in the readings will not be correct (ie too much air = lean).

why are you trying to move the sensor? unless you are more than moderately modified theres no reason
 

Poodles

I play with fire
Jul 22, 2006
16,757
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Fort Worth, TX
Sounds like he's talking aobut using the hot-wire MAF off of a GM car in a blow through configuration.

There are issues doing it that way, and as long as your intercooler piping is leak free having it before the turbo is just as good without the drawbacks...
 

str8_6

master yuepeng
Mar 14, 2007
241
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wa
i know, as you do, a lot of nissan guys do this. might want to read up on what problems they have..tuning issue/s, etc

i know its a different engine, but similar concept. Could give you an idea of future problematic issues
 

bloodasp90

JZwhore of JAPAN
Nov 9, 2007
529
0
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on the river
well thats what i was talking about, cause right now im stationed in japan, and ive seen a few nissan and some suby guys do this, where they change the placement of the MAF after the turbo but just before the throttle, so i was just wondering whats the ups and downs to this, ive talked to a few of them, and they all said they had to change the type, but they didnt say what to, and that they've been able to more finly tune there cars on the higher numbers due to that they're ECU's are reading what air is moving more into the engine insted of that into the turbo.
 

supraguy@aol

Well-Known Member
Dec 30, 2005
4,231
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Atlanta
I've run the MAF-T in suck-thru and blow-thru mode, but again, that's using a GM sensor. It won't really work with our OEM units. I have the MAF about 1.5 - 2ft from the TB in the IC piping.

p1195767_1.jpg
 

ihiryu

Member
Jul 12, 2008
209
0
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TX
The reason why you do this is because hot wire sensors need a pulse (from the TB opening and closing) to "activate". When the maf is at the turbo, the pulse needs to go from the TB->hot pipe->IC->charge pipe->turbo->maf. So there is going to a split second that you will have load, and the maf not know it.

it's really a throttle response/atmo bov deal. Is it worth it? Yeah if you are trying to fine fine tune your car. As a previous nissan guy, I didn't seem much a difference.