How Much Is My Stock Mass Air Hurting Me?

Discussion in 'Fox 5.0 Mustang Tech' started by 89llx, Jul 26, 2014.


  1. 89llx

    89llx Member

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    I have an 89 GT with 2800 stallion converter, cobra intake, edl heads, stock cam with 1.7,s - 70mm throttle body, 410 gears, and a stock mass air meter with stock injectors.

    How much do you think I would gain with a bigger mass air?

    THANKS!!!
    #1
  2. omarimoe

    omarimoe Active Member

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    Not sure I understand what your asking. Just a bigger tube or a bigger maf calibrated for bigger injectors? If you get a new maf for say 24lb injectors the car will run like crap If you dont also upgrade to the correct injectors. If you just mean a bigger tube the gains will probably be minimal.
    #2
  3. 2000xp8

    2000xp8 Mustang Master

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    A pro m bullet on a stockish engine is good for .2 in the quarter.
    #3
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  4. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

    94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

    Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

    *1.) Metal flange adapter http://www.kustomz.com/cat3.html Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.

    *2.) MAF & sensor interchange
    The 94-95 Mustang 5.0 MAF & sensor is also found on:
    1995-94 Mustang 3.8L F2VF-12B579-A2A,
    1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
    1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
    1994-92 Town Car 4.6L F2VF-12B579-A2A,
    1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
    Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

    Swapping the MAF sensors between different MAFs is a big no no. The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

    The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.
    #4
  5. 89llx

    89llx Member

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    What about a 93 cobra mass air meter, would it be a direct swap to mine , with my 19 lb injs,s ?
    #5
  6. modulistic

    modulistic Member

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    no. need 24lb injectors
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  7. mikestang63

    mikestang63 Mustang Master

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    Sorry about the hijack-I have a 95 gt 70MM MAF with the flange to fit your stock intake tube for sale if you want it $50 plus the ride. Just took it off my car when I swapped to 30's and a Pro M.
    #7
  8. Dave2000GT

    Dave2000GT Active Member

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    It's well worth it. Like at least 5hp.. So if you get one for a deal like the one above.. Thats $10/pony which is about the best you can do for any bolt-on
    #8
  9. Onefine88

    Onefine88 Previously 89SSC18

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    You can get a 70mm Cobra meter calibrated for 19s on Ebay for around $50. I put one on my car last year and it ran great. Great plug and play meter for the money.
    #9
  10. 89llx

    89llx Member

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    STANGNET ROCKS

    To me I dont know if it is worth the small horsepower gain, the car starts and idles like new.

    So is it worth 5hp to mess with it?
    Last edited: Jul 27, 2014
    #10
  11. stykthyn

    stykthyn Commander of the snuggie cultists

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    To me the difference wasn't the hp. The engine revved easier and pulled harder in the mid to upper range. That was worth it. 50 bucks?? That's a steal, especially if it's bolt on ready.
    #11
  12. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

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    I would never consider swapping out a maf until its time to upgrade to bigger injectors
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  13. 2000xp8

    2000xp8 Mustang Master

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    I disagree.
    A 75mm bullet is only like $100 on the used market.
    When you goto better engine parts you can sell it for exactly that.
    When your car runs 13.8 (pretty much stock) and a $100 meter gets you to 13.6, that's a nice gain.
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  14. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    No. Go back and read the first line of my first post...

    The MAF assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.
    #14
  15. 89llx

    89llx Member

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    where are you located?
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  16. stykthyn

    stykthyn Commander of the snuggie cultists

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    He lives between the border of yuppie abd hillbilly hell
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  17. 89llx

    89llx Member

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  18. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    Is that the one I sold you 2 years ago?
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  19. mikestang63

    mikestang63 Mustang Master

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    I believe so. Works like a charm. Only reason I am selling is because I went to bigger injectors.
    #19
  20. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    Good, glad to hear.
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