is a iat better or a mass air flow sen?
What do you mean my "better". Do you mean is speed density or mass flow better? It's hard to say, they both have their pros and cons. For the record though, speed density uses an IAT and a MAP, not just IAT (some Alpha-N systems use just an IAT).
MAF (mass flow) is very accurate because it measures actual airflow into the engine, but the MAF is also a restriction and has a limited reading range. It is also very easy when modding the car because it can see the extra airflow from new parts and it's also relatively idiot proof. Modifications that increase volumetric efficiency are automatically compensated for (within the reading range of the MAF). There's also a wide range of MAF types that widely vary in accuracy and restriction, ranging from extremely accurate Karman-Vortex used on Supras, DSMs, and older Lexus' to the inaccurate but unrestrictive GM hotwire used on many LSx engines, to the unaccurate and extremely restrictive flapper door style used on many very old import and domestic vehicles.
MAP/IAT (speed density) combo is what standalone systems like AEM, Motec, Haltech, etc use because it's easier to work with when doing in depth tuning. However, it's limited because it can't actually see the air entering the engine. It looks at surrounding conditions and makes an educated guess, which can be off from actual airflow if it hasn't been tuned correctly. It's also needs to be retuned any time volumetic efficiency is upped by something like bolt ons, cams, headwork, etc. MAPs also have limited reading ranges, usual rated in BAR. 1 bar is good for N/A applications. 2 bar is good for ~15psi of boost. 3 bar is good for ~30psi. etc
Hopefully that answered your question and hopefully that's what you wanted to know otherwise I'm going to feel dumb for typing all that.
______________________________
'96 GSX
towed more often than driven
Low Boost - 12.31 @ 115
- 349awhp/304ft.lbs
i know i have a j but my g/f just got a new bolt and i saw it has a maf and i just wanna to know witch was better cuz after all these years of puttin MAP/IAT in js now they put maf in there. awdstylez thank u thats what i was looking 4 very good info there thanks
Mark wrote:Rich Grayo Jr. wrote:also, it doesnt matter if you have a j, because they dont have MAF sensors.
Exactly 
not true... some 97's came with them
i know this is kinda old but i just thought i would let you know
TheGreenMachine(isnt so green) wrote:Mark wrote:Rich Grayo Jr. wrote:also, it doesnt matter if you have a j, because they dont have MAF sensors.
Exactly
not true... some 97's came with them
i know this is kinda old but i just thought i would let you know
Not a single J body came with a MAF sensor.
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