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  1. #1
    Sr. Engineer
    Join Date
    Jun 2009
    Location
    San Diego, CA
    Posts
    426

    Post Aftermarket Air Flow Sensors and Descreening

    I frequently get questions regarding aftermarket MAF sensors/descreening and what gains they will net. My answer to that question 9 times out of 10 is: NONE as the OEM unit can handle ~550HP.

    The aftermarket MAFs are not calibrated the same as the stock MAF. So, for a given volume of air, the aftermarket MAF will underreport that volume, this causes the PCM to increase ignition timing slightly, which is the resulting increase in power.

    When tuning for an aftermarket MAF, the PCM will be recalibrated so that the MAF reports correctly (or close to correctly), thus leaving no real benefit to the aftermarket MAF. Descreening has the same effect as an aftermarket, and has no benefit other than underreporting the incoming air.
    Black Bear Performance- Custom Tuning Solutions

    Authorized EFILive and MAGNACHARGER seller

  2. #2

    Default

    Quote Originally Posted by JennaBear View Post
    I frequently get questions regarding aftermarket MAF sensors/descreening and what gains they will net. My answer to that question 9 times out of 10 is: NONE as the OEM unit can handle ~550HP.

    The aftermarket MAFs are not calibrated the same as the stock MAF. So, for a given volume of air, the aftermarket MAF will underreport that volume, this causes the PCM to increase ignition timing slightly, which is the resulting increase in power.

    When tuning for an aftermarket MAF, the PCM will be recalibrated so that the MAF reports correctly (or close to correctly), thus leaving no real benefit to the aftermarket MAF. Descreening has the same effect as an aftermarket, and has no benefit other than underreporting the incoming air.
    Thanks for clarifying that. I've seen lots of posts claiming an increase in power,

    One question thought. Do the aftermarket MAF sensors self clean or stay cleaner than the stock sensor?

    Thanks!
    Jim

    2004 SILVERADO 2500HD LS
    Pro Comp Leveling Kit
    285-75-16 Cooper ST All Terrains
    Pro Comp Programmer
    Bilstein Shocks
    Linux Bed Liner
    Tinted Windows



    Other rides:

    1967 Landcruiser <350 Chevy>
    1970 Camaro
    1990 Geo Metro Convertible
    2007 FJ Cruiser

  3. #3
    Sr. Engineer
    Join Date
    Jun 2009
    Location
    San Diego, CA
    Posts
    426

    Default

    Quote Originally Posted by Jimmiee View Post
    Thanks for clarifying that. I've seen lots of posts claiming an increase in power,

    One question thought. Do the aftermarket MAF sensors self clean or stay cleaner than the stock sensor?

    Thanks!
    No they don't self clean or stay cleaner. I know of one aftermarket sensor that actually uses the OEM sensor and just throws their sticker on it.
    Black Bear Performance- Custom Tuning Solutions

    Authorized EFILive and MAGNACHARGER seller

  4. #4

    Default

    Quote Originally Posted by JennaBear View Post
    No they don't self clean or stay cleaner. I know of one aftermarket sensor that actually uses the OEM sensor and just throws their sticker on it.
    LOL, probably SFI approved too!
    Jim

    2004 SILVERADO 2500HD LS
    Pro Comp Leveling Kit
    285-75-16 Cooper ST All Terrains
    Pro Comp Programmer
    Bilstein Shocks
    Linux Bed Liner
    Tinted Windows



    Other rides:

    1967 Landcruiser <350 Chevy>
    1970 Camaro
    1990 Geo Metro Convertible
    2007 FJ Cruiser

  5. #5
    Jr. Mechanic
    Join Date
    Nov 2008
    Location
    Northern Colorado
    Posts
    75

    Default

    I descreened mine on my 05 and really haven't noticed anything. It wasn't that dirty though to begin with. I have never thought to much of getting an aftermarket one.
    My first Chevy :great:
    2005 Silverado 1500 ECSB Z71 5.3L:
    3'' Aero Turbine exhaust with side dump
    6000k HID's Highs, lows and fogs with H-4 mod
    Rough Country Full Leveling Kit
    285/70/17 Firestone Destination A/T's
    Dick Cepek DC1
    EFI Live
    more to come..

  6. #6

    Default

    i have an aftermarket one not much of a difference my factory one went out and it was cheaper to get the aftermarket one kinda like those shorty headers that leaked all time i use to have you get what ya pay for xD
    Last edited by grimreapersshadow; 06-22-2009 at 08:18 PM.

  7. #7
    Sr. Engineer
    Join Date
    Jun 2009
    Location
    San Diego, CA
    Posts
    426

    Default

    Yeah I try to sway most folks into getting the long tubes, as the shorties are just as efficient as the stockers.
    Black Bear Performance- Custom Tuning Solutions

    Authorized EFILive and MAGNACHARGER seller

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