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Question about stock MAF sensor

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Old Jul 7, 2004, 12:20 PM
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Question about stock MAF sensor

Hi,

The other week when I installed a cone-type air filter, I accidentally bent some of the "honeycombs" on the MAF sensor.

My car is now not pulling as hard and I hear this air suction sound. Not sure if that's from boost leak or if it's normal sound from air rushing into the turbo.

Anyway, my question is, would a few bent honeycombs affect the car's performance?

By the way, if you have one for sale, please PM me.

Thanks.
Old Jul 7, 2004, 12:24 PM
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air suction sounds is normal on short ram. It's not pulling hard, cause it's not getting enough air in to the engine? cause you're just getting hot air... maybe?,.
Old Jul 7, 2004, 12:25 PM
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I don't know about the bent fins affecting it but I did install a K&N intake on my '03 Evo and had the same condition. The thing would really let up and kind of surge at anything above 4500 to 5000 RPM's. Ended up putting the stock intake back on and going with a K&N drop-in filter.

HTH,
Bob
Old Jul 7, 2004, 12:28 PM
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I've got the Bushur intake filter on the stock MAF pipe and I can hear the sounds, but have not lost any go. Originaly I was confused by the immense change in sound; so it was throwing off the butt dyno.

What intake did you put on?
Old Jul 7, 2004, 12:46 PM
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a cone air filter will result in MAF misreads. search the engine forum, then remove it and go with the K&N panel filter in the stock airbox.

I'd only use a cone air filter on a car running MAP only. lots of proof of this concept-- good posts over on Nasioc in particular and their search engine is way easier to get results out of.
Old Jul 7, 2004, 12:58 PM
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Interesting. All the reading I've done says an open element filter leans the car out a bit and can be completely tuned around. I'll give Al a call at Dynoflash and tell him right away to stop suggesting the Buschur and HKS intakes on your word.
Old Jul 7, 2004, 01:12 PM
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cone air filters are for high ends anyway. You'll loose a lot of low end, unless you're doing 7k grand drop launches.

happens with all cars.
Old Jul 7, 2004, 03:12 PM
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Originally Posted by siantjab
Interesting. All the reading I've done says an open element filter leans the car out a bit and can be completely tuned around. I'll give Al a call at Dynoflash and tell him right away to stop suggesting the Buschur and HKS intakes on your word.
I'll see your rolleyes and raise you with a

it's not my word... you aren't looking hard enough. try searching for "MAF misread" especially on nasioc.com--yes it's a subaru but it's still a MAF-equipped turbo car. it cannot be tuned around because the amount of misread is not consistent as the throttle input is varied.

I don't give a rats *** if you flame me... and trusting a vendor selling you something over fellow enthusiasts and their own experiences is your choice.

"if it's available it's gotta be a good idea to install it on my car!"
Old Jul 7, 2004, 04:15 PM
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The Mesh is there to create voticies in the incoming air which the MAF sensor reads to determine the amount of air (Von Karman Vortex Sensor). If you bend them you cut down on the accuracy of the sensor and degrade the performance substantially.
Get a new one and watch out for the mesh!
Old Jul 7, 2004, 04:19 PM
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By the way, there is truth to the cone filter, lean/rich thing, especially the HKS RS (which I have). It needs to be tuned via fuel computer, reflash or standalone.
Old Jul 7, 2004, 04:36 PM
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can it be tuned out completly or will it still fluctuate
Old Jul 7, 2004, 04:43 PM
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Originally Posted by siantjab
What intake did you put on?
I have a K&N intake....

Originally Posted by ColinL
I'd only use a cone air filter on a car running MAP only.
What is "MAP"?

Originally Posted by bishiboy
It needs to be tuned via fuel computer, reflash or standalone.
If I get something like an XFLASH (from Vishnu) or P2 (from WORKS) would it fix my problem with the low boost?

Thanks for the responses so far.
Old Jul 7, 2004, 07:05 PM
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from what i've gathered, it seems a number of ppl with the typhoon intake is having issues... maybe diameter issue??? but i would also imagine those bent fins aren't gonna help...
Old Jul 7, 2004, 08:22 PM
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MAP = manifold absolute pressure. it's a barometer.
MAF = mass air flow. it's a hot wire or hot film that meters airflow based on temperature.

cars with a MAF use *both* types of sensors to compute airflow.

cars without a MAF use only manifold pressure and they inversely compute the flow. it's less accurate especially during part throttle transitions. that's why Mitsubishi, Subaru and others even bother to have the MAF in the first place-- before someone asks.
Old Jul 7, 2004, 08:25 PM
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Its nice to see there is someone who actually understands what the real difference between a MAF system and a Speed Density system..


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