Difference between MAP and MAF sensors

Post by **Sean @ NDF** » June 12, 2006

Is it just location?

Secret Squirrel · Post by **Secret Squirrel** » June 12, 2006

i just read a whole thing on nicoclub about mafs and maps and running vented bov....i think they use different ways to measure air flow....i kno that on turbo cars, the maf measures the air goin into the turbo, and the map measures absolute air entering the throttle body...thats why venting on ca18dets cause bogging because it measure the air coming in the intake and doesnt take into account the air lost out the bov....idk...im an idiot

SS

trbobrk · Post by **trbobrk** » June 13, 2006

^Yep your right.

They are two different technuiques for calculating the amount of air entering the engine so the ECU knows how much fuel to inject.

MAF = Mass air flow, measures the mass of the air flowing by the sensor.

MAP = Manifold air pressure, measures the air pressure in the intake.

With a vented blow off valve, the amount of air has already been measured and then leaks out so the car will run rich when the BOV opens beacause it expects more air but doesn't get it.

MAP runs directly on pressure in the intake. When the BOV opens the air leaks out and the pressure drops.

I don't know which is better, I'm sure both have some good aspects as well as drawbacks. I think most if not all Nissans are MAF. Subaru changes back and forth between the years, I use a MAP sensor for my standalone system for the Subaru at work.

Post by **Sean @ NDF** » June 13, 2006

yea I was reading about them on turbo apps. with bov's, and was curios about the whole running rich thing...oh well, i rather run rich on my car than lean lol

Secret Squirrel · Post by **Secret Squirrel** » June 13, 2006

yea the only downside is fouling plugs and blowin flame...but fuck...thats cool

SS

Post by **Sean @ NDF** » June 13, 2006

who cares about fouling plugs when you change them every month anyway?

Secret Squirrel · Post by **Secret Squirrel** » June 13, 2006

this might help

http://forums.nicoclub.com/zerothread/177791

Post by **Sean @ NDF** » June 13, 2006

yea, good reassurance

Post by **Nikku** » June 13, 2006

http://en.wikipedia.org/wiki/MAP_sensor

http://en.wikipedia.org/wiki/MAF_sensor

they both approach the same concept from a different angle.