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Thread: 76mm MAF housing on LNF

  1. #1
    Tuner in Training
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    76mm MAF housing on LNF

    Hello

    What is the top limit a 76mm MAF housing can handle in g/sec ?
    I'm struggling on 256 g/sec but guess should be higher on this size?

    Marc

  2. #2
    Senior Tuner cobaltssoverbooster's Avatar
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    Put it in a 3" tube and calibrate it accordingly. That tube will flow well over the capabilities of the factory computer.

  3. #3
    Advanced Tuner |V3nom|'s Avatar
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    doesnt a blow through work better than a pull through? also since the lnf is turbocharged maf housing size doesnt really matter power wise right? i know bigger maf housings are used on N/A applications but not needed on F/I.
    2008 Sky RL

  4. #4
    Senior Tuner cobaltssoverbooster's Avatar
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    i think your thinking of the tb...and yes a tubing restriction pre-turbo or supercharger would also cause a vacuum on the backside robbing a user of power.
    2000 Ford Mustang - Top Sportsman

  5. #5
    Advanced Tuner |V3nom|'s Avatar
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    Quote Originally Posted by cobaltssoverbooster View Post
    i think your thinking of the tb...and yes a tubing restriction pre-turbo or supercharger would also cause a vacuum on the backside robbing a user of power.
    nope im talking about a maf sensor. ive seen the pull through in the intake tube changed to a blow through in the cold side ic pipe. gmtech and others have done this.
    2008 Sky RL

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    maf re-locate is a common cure for atmospheric bov, otherwise there is no reason to move it. one position is not more accurate than the other when calibrated correctly. the only draw back to a maf tube pre turbo would be on a large aftermarket turbo setup. the factory tube should be 3" which is the same size as any turbo that the lnf would be able to run even for drag racing. the factory turbo inlet pinches down so as far as restrictions go the turbo is still the restriction when compared to the factory maf tube.

    @ 40 psi a 100' length of 3" tubing will flow 1,100 SCFM @ 5% pressure Δ
    @ 20 psi a 100' length of 3" tubing will flow 600 SCFM @ 5% pressure Δ

    given the average performance vehicle will run close to an average of 2.2 cfm/hp (this is not concrete as the cfm/hp is a fairly mild sized calculation) we can calculate max hp for the minimum tube size of 3".
    600 X 2.2 = 1320 hp @ 20 psi
    1100 x 2.2 = 2200 hp @ 40 psi

    obviously the lnf is pre turbo so the tube would be rated in atmospheric or inhg tubing restriction. The cfm rating for a tube at 15" wc of 3" pipe MAY be able to
    flow approximately 898 CFM. if we considered that as best case then you are around 1975.6 HP.
    2000 Ford Mustang - Top Sportsman

  7. #7
    Advanced Tuner |V3nom|'s Avatar
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    thats way too many numbers for me to look at and understand right now lol.

    the bov was one reason and apparently cfms were too, as you intelligently described but there was another. the other reason it was done was because of air turbulance in the stock airbox (on kappas, not sure about cobalts) distorting the maf readings and making them go all crazy due to the bends directly before and after the maf. relocating them to the cold side ic pipe provided a long section of straight pipe to get a smoother reading (if i can remember correctly, using a honeycomb helped some but didnt completely fix the problem with the maf in the stock location or on an aftermarket intake).

    gmtech was one of the first i saw to do this (again in a kappa) and he could explain it better than me for sure since he logged and tested everything.
    Last edited by |V3nom|; 09-07-2014 at 07:26 PM.
    2008 Sky RL