MAF and IAT sensor placement
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Pro
Joined: Jul 2000
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From: Washington, USA
MAF and IAT sensor placement
Do the MAF and IAT need to be on the same side of the compressor? For those of us who don't have the IAT built into the MAF, should they be in the same part airflow? I want to place my IAT just before the throttle body.
Melting Slicks
Joined: Mar 2003
Posts: 3,116
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From: Macomb MI
MAFs can be located in either a draw thru or blow thru. I prefer blow thru as its a more accurate representation as to what the motor is seeing. Both can be made to work well. The only drawback is the ocasional issue of the composite maf blowing apart.
Nick, You can seperate the IAT from the MAF circuit and convert to the pre2000 IAT sensor. Easy hookup and you will have IATs which are very important.
Phil
Nick, You can seperate the IAT from the MAF circuit and convert to the pre2000 IAT sensor. Easy hookup and you will have IATs which are very important.
Phil
Supporting Vendor
Joined: Jul 2003
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From: http://www.mphparts.com 800-364-1975
I did the conversion Phil is describing above. It's nice because I can log what my IATs are before alky spray and after alky spray, whereas with my factory MAF/IAT combo I could not see how my alky was affecting the car. Also the sensor is less than $20 so it's a cheap mod 
The only thing I would add is that the PCM does in fact use readings from your MAF and readings from your IAT sensor to determine how much air is going through your plumbing, so I wouldn't personally place the MAF in front of the compressor and the IAT in the airbridge... a little separation is OK but a lot is not ideal.
But then, what do I know... I'm just a noob
The only thing I would add is that the PCM does in fact use readings from your MAF and readings from your IAT sensor to determine how much air is going through your plumbing, so I wouldn't personally place the MAF in front of the compressor and the IAT in the airbridge... a little separation is OK but a lot is not ideal.
But then, what do I know... I'm just a noob
Le Mans Master
Joined: Oct 2003
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From: PA
St. Jude Donor '08
Originally Posted by RoadRebel
MAFs can be located in either a draw thru or blow thru. I prefer blow thru as its a more accurate representation as to what the motor is seeing. Both can be made to work well. The only drawback is the ocasional issue of the composite maf blowing apart.
Nick, You can seperate the IAT from the MAF circuit and convert to the pre2000 IAT sensor. Easy hookup and you will have IATs which are very important.
Phil
Nick, You can seperate the IAT from the MAF circuit and convert to the pre2000 IAT sensor. Easy hookup and you will have IATs which are very important.
Phil
thanks, ill need to buy the sensor and tap center tube. the current maf plug has the wire that will convert to pre2000? which ones? phil appreciate as car is scheduled for tune on 18th and not having IAT would be BIG negative
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From: http://www.mphparts.com 800-364-1975
Originally Posted by ramcharger
for the purposes of calculating the airmass in the ECU, does it assume the mass of air flowing through the MAF is at the temperature detected by the IAT thermistor?
It's worth noting that when spraying the alky, my IAT sensor reads REAL low compared to the air mass flowing through the MAF, but I'm OK with that since it only happens at WOT.
Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Originally Posted by ramcharger
for the purposes of calculating the airmass in the ECU, does it assume the mass of air flowing through the MAF is at the temperature detected by the IAT thermistor?
The meter measures the mass thru the MAF. It does not calulate it.
The reading in indepentant from the IAT. The IAT reading does impact fuel and spark and many others.
Phil
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Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Originally Posted by NICK YOSKIN
thanks, ill need to buy the sensor and tap center tube. the current maf plug has the wire that will convert to pre2000? which ones? phil appreciate as car is scheduled for tune on 18th and not having IAT would be BIG negative
Phil
Supporting Vendor
Joined: Jul 2003
Posts: 6,486
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From: http://www.mphparts.com 800-364-1975
Originally Posted by RoadRebel
noob can post up the info, its fresh in his brain
Phil
Phil
<------------- That's why I picked my avatar. It fits me perfect.
BTW, here's a pretty cool read on how some MAFs work.
http://www.kemparts.com/TechTalk/tt06.asp
Thread Starter
Pro
Joined: Jul 2000
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From: Washington, USA
I understand that. However, there's a function within the ECU that takes into consideration a number of inputs to calculate air mass in grams per cylinder. MAF is one. VE table is another. and I'm pretty sure IAT is, as well. I don't know the function; maybe I should ask over at the hptuners forums.
Anyhow, I want to know how having the MAF in draw-through and the IAT in blow-through affects that calculation.
Anyhow, I want to know how having the MAF in draw-through and the IAT in blow-through affects that calculation.
Originally Posted by RoadRebel
The meter measures the mass thru the MAF. It does not calulate it.
The reading in indepentant from the IAT. The IAT reading does impact fuel and spark and many others.
Phil
The reading in indepentant from the IAT. The IAT reading does impact fuel and spark and many others.
Phil
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
The MAF sensor converts mass flow to a frequency which is read by PCM. The IAT can be separated from MAF, Mag does this on their kits and actually supplies sensor and wiring. There installation PDF has a diagram which would be a good starting point.
Mike
Mike
