I'm a little new to TPI and will be retrofitting my 56 Chevy Pickup w/an 87 T/A TPI unit. If I retain the MAF, is it critical where it is located? That is, can it be placed anywhere in the cold air intake ducting?

 

Yes it can pretty much go anywhere, just make sure you have the air flowing the proper way. I think they are sensitive to air direction.

james

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If the women don't find you handsome they should at least find you handy

 

anywhere is ok, BUT the closer the MAF is to the throttle body the more accurate the sensor meatures. Because the sensor measures the a coming in and tells the ECM how much fuel to mix and at what coumputer controlled advance us nessasary for the amount of air coming in. $ hint $ gut the hell out of that thing. It can increase flow by 182 cfm making a 48mm throttle body about 800cfm (with foil)

 

and if you don't know how to gut that beast refer to the thirdgen.org home page they have it put beautifully!! a little looking is required

 

If the cold air ducting has no leaks in it how can the accuracy of the MAF be diminished by virtue of its position?

 

the temp of the air going through the MAF is at (x)temp and then it enters your throttle body and your intake where the air will expand to the difference in (y)temp. So the temp of the air in MAF sensor is cooler then the temp of the air in the intake. Therefore your computer reads that you have this amount of air and then it enters the intake expands to the temp of the intake and you end up with less air in the mixure than the computer thought you had.

y-x= the difference in computer reading and the true readings
So the closer the MAF the more accurate the Readings

 

If the air passes the MAF, thats how much air the engine is getting no matter what the temperature is. Only way your theory would apply is if the air went somewhere else when it expanded, but since its a sealed system and it doesnt flow back past the MAF, the amount of oxygen calculated by the MAF remains the same no matter what the temperature is.

 

Placing the MAF farther away from the TB wont effect the air ratings from the MAF..

You have to think, I used a MAF before the Vortech S-Trim on my car. The MAF literally was mounted down by the front bumper...The air passed through the MAF, entered the blower, heated up about 30-40 degrees from when it entered, and forced into the TB.

If FunPains theory was correct, my car would have had serious problems.... All SCed MAF cars run this way.

[This message has been edited by Kevin G (edited September 27, 2000).]

 

in the case of critical? no kev is right your car will run fine were he said but all i'm saying is that is will be more accurate the closer it is. The main reason besides mathmatics, is that if you drag alot, your car will heat up therefore that same amount of air will too and the air then exspands.Filling the intake with less air.

try and blow up a balloon, then hold a lighter below it. The balloon will inflate more than is all ready is because the air will exspand. Like your engine will do to the air it gets. (don't hold the lighter too close that it burns the balloon. the smell it pretty naste, kinda like glasspacks... HAHA

 

Where does the air expand to? It cant, its contained in metal surroundings unlike a balloon, which can and does change in volume. The internals of an engine dont change volume like that.

 

i think he means that when the air is hotter it thins out holding less o2 per cubic inch thats y a cold air intake is good in the first place, if its cold its denser therefor holding more 02 per cubic inch hence more power

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1988 IROC 305TPI MINT!!
Mods= Accell SuperCoil, MSD 6A, Ported Plenum, No MAF Screans , K & N, 160 Thermostat+ Temp Switch
And Always Trying To Go Faster

 

While that is true, the amount of air (or oxygen) that passes the MAF remains the same no matter what temperature the air changes to, because it has nowhere to escape to. I just want to make sure that is clear, because the actual location of the MAF in that case does not matter, which was the original question.