Swiss cheesed my OE airbox today

Discussion in 'Fiesta ST Engine Upgrades' started by moshaholic2, Feb 13, 2014.

  1. moshaholic2

    moshaholic2 Active Member

    Simple 20 min mod.

    We used to do this on old MK1 GTi's back in the day as "cold air intakes" didnt exist. Install a higher flow panel filter and open up the airbox some.

    After looking at the OE box and washing the car a bunch, I noticed the side near the headlamp doesnt ever really get hit by water. All I was really looking for is a little more intake noise and *hopefully* a little more airflow from a point that is furthest away from the engines heat.

    You can definately hear the turbo sounds now as well as some more induction noise. Haven't driven enough to determine if there were any other differences as quicker spool or more responsive throttle. But, it was FREE :)

    ronnie karlen, onederer and Firesail like this.
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  3. onederer

    onederer Member

    :thumbsup: I was considering doing something similar. I just want a little more induction/turbo noises to placate the 18 year old in me. Oh, and to not have to pay $300 bucks for it.
  4. MadMoose

    MadMoose New Member

    Me too. fswerks sells just the open conical filter portion for the Focus ST for $60 and im hoping they do the same for the Fiesta
  5. reddog99

    reddog99 Active Member

    Actually, drilling holes in the airbox isn't such a great idea if you expect a performance increase. The stock box sucks COLD air from in-front-of, along-side-of the radiator. You've just modified the box to suck in hot engine compartment air... :(

    If all you're looking for is more noise, then you did right. :)
    Last edited: Feb 14, 2014
  6. moshaholic2

    moshaholic2 Active Member

    No i didnt. Re-read it as its directly behind the headlight, the furthest point away from the radiator and engine that you could possibly get, close to the headlight and hood seam. In the same location other tuners are putting their open filters w/ no shielding. Not to mention the front intake is still in place.
  7. reddog99

    reddog99 Active Member

    I don't know what your ST looks like, but on mine, behind the headlight is still inside the engine compartment...
    Last edited: Feb 15, 2014
  8. onederer

    onederer Member

    Don't sweat the air temp thing. These cars have a very effective intercooler for stock applications. The charge gets heated up plenty just by getting compressed and running through a hot piece of metal. And since it sits on the far side of the engine compartment those temp increases will be minimal.

    Since these cars are also MAP based, if there were any increases in air flow it too would have a negligible effect on performance.
    For me, it's just about being a little more fun to listen to while driving around. Ricer? Sure. Do I care? Nope. Plus...I am cheap, I drive a Ford Fiesta! :rotfl:

    The pluses of this tiny mod outweigh the minuses for me. Just have fun.
    moshaholic2 likes this.
  9. mamiata1

    mamiata1 Active Member

    I literally took a different route and opened up the bottom of the air box with a hose that goes to a scoop under the front air dam. It definitely is cold down there!
    reddog99 likes this.
  10. moshaholic2

    moshaholic2 Active Member

    Man it IS hot in there!

    Ambient temp

    After a triple digit speed climb gaining 2000' elevation
    over 15 miles
    (Ghetto rigged thermometer next to holes behind headlight- battery was dead in my digital one)

    Whopping 42'

    Pretty sure the IC can handle that.
    Sekred likes this.
  11. RodMoe

    RodMoe Well-Known Member

    Was this before or after the decimal point LOL :wideyed:
  12. reddog99

    reddog99 Active Member

    Well, I must say that measured data trumps theory every day!
    I'd be interested to see what that number would look like when it's 85 deg. out.
  13. moshaholic2

    moshaholic2 Active Member

    I imagine in a traffic situation and the summer heat it does get warmer in there. Too much for the IC to compenstate for? Guess we'll have to wait and see.

    Fortunately around here, I dont sit in traffic much.

    I kinda guessed it wasnt getting that hot in that corner just by touch (before I used the thermometer or did the mod).

    Just w/ your hand you could feel the difference between the engine side of the airbox and otherside.
  14. wash

    wash Active Member

    What you really need to test the effectiveness is a manometer.

    Plumb one side in to an intact air box, then plumb the other side to where you want to get air. When you find positive pressure with no water intrusion, you're probably in the right spot.

    Stagnant air and radiated heat are how you can get hot spots. If the air is moving and there is no line of sight to the exhaust, it should be ~cool.
  15. djdennehy

    djdennehy Active Member

    Its a Fiesta, not a antique Ferrari, messing around with it is part of the fun...
  16. wash

    wash Active Member

    That's funny, in a lot of ways a Fiesta is built much better than an antique Ferrari.

    Funny story: a vintage racer friend of a friend with a Ferrari 250 or something (old front engine V12) was accused of butchering his Ferrari when some tifosi saw a bunch of ugly welds on the chassis. The ugly spots were the only original parts left (such is the life of a race car).

    I don't think they can get away with that in a carbon fiber car but if its aluminum or steel, there are probably a bunch of uglies lying beneath the skin.
  17. onederer

    onederer Member

    Ok, How the Hades do you get the bottom of the airbox out? Is that sumbitch bolted down? It looks like it's just held with rubber mounts.
    I wiggled, cussed and tugged that thing and nada. It's like one of my regular Saturday nights.
    mrtn likes this.
  18. mrtn

    mrtn Active Member


    But seriously though, a write up on the removal would be good. Was hoping Mountune would post their info on their intake install someday.
  19. RodMoe

    RodMoe Well-Known Member

    Once the air box lid is off with the 4 torx screws there is only the one torx screw left that holds the airbox to the front support beam on the car once that is removed it only takes a firm hand and good tug or two to pop the bottom of the airbox out of its holders..

    Here in this Mountune Pic you can see the Torx screw to the left of the YELLOW hold rod holder on the Aluminum moutnune AirBox Bottom...
    Last edited: Mar 14, 2014
    ronnie karlen likes this.
  20. moshaholic2

    moshaholic2 Active Member

    Yup, and the front snorkel holds it in place pretty well too. I think I popped out the snorkel before lifting the base.
  21. BlueBomber

    BlueBomber Active Member

    I had no problem with it, I just pulled on it and popped out. Pop off the snorkel first, removed that little torx bastard, and then off it comes.
    ronnie karlen likes this.

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