[downest]

Not sure exactly where this should be posted...

Anyway, I have a friend who says that a MAP system, as opposed to MAF, is superior, and he's always been impressed that Honda used MAP. Well, I realised earlier that the new Civic has a big ole restrictive MAF sensor! Could someone explain the theory behind it to me? I can see on a basic level that the MAF sensors restrict flow, and they way they work requires that they constantly alter the quantity they are measuring, and MAP are more solid-state, benign sensors. Why would Honda switch to MAF if it's inferior, is it cheaper?

 

[lessonsinspeed]

I just so happen to be reading a book on this...

MAF systems are restrictive and slow to respond to quick changes in the load. Advantages include the ability to compensate for mechanical fluctuations in volumetric efficiency of the engine and to compensate for simple modifications.

MAP systems (speed-density) respond more quickly to rapid load changes and don't restrict airflow, but can't compensate for a reduced volumetric efficiency in the engine or respond to modications well.

As for why Honda made the switch, I have no idea.

 

[jfrolang]

I remember seeing a video on Temple of VTEC, where a Hondata technician was explaining the 2006 Civic Si's electronics setup. He was saying that the MAF is making it harder for them to tune it.

They've probably worked around that by now though.

 

[mattminerDOTcom]

MAFs are kind of a pain. Ive had alot of experience with them on subies and nissans.

A few examples and some interesting facts.
Our 02 2.5RS is MAP based and our 02 WRX and 04 STi are MAF based.
Most factory turbo cars appear to be MAF based.

We converted our KA24DE-T car to a map sensor when we switched to SDS engine managmeent, made it a hell of alot easier then the old setup using a 300ZX MAF and recalibrating the computer through a piggyback.

The 300ZX im working on, we were able to get an upgraded MAF that could read higher airflow, we just had to reprogram the zemulator for it.

You dont want to use a BOV with a MAF sensor, as it will cause a rich condition after blowoff. I know people do it all the time, but it is dumb.

The calculations the ECU has to do from a MAF sensor are much easier, since you know the exact airflow. With a MAP sensor, the computer depends alot more on the TPS.

VW MAFs are prone to failure.

MAF's tend to be restrictive, and if you start changing parts around them, will give incorrect readings.

 

[CRXSIR1]

Excellent write up. Thanks