LTT True Cold Air Intake for KJ's

Discussion in 'KJ General Discussion' started by long_tall_texan, Feb 9, 2009.

  1. 501

    501 Full Access Member

    Messages:
    452
    Likes Received:
    0
    Joined:
    Jan 20, 2008
    Location:
    Michigan City, Indiana
    This image of you ding this in my mind just keeps me laughing Socks! Thanks for starting my day out with a good laugh!!

    AMEN Brother!
     
  2. flair1111

    flair1111 Full Access Member

    Messages:
    847
    Likes Received:
    0
    Joined:
    Jul 10, 2007
    Location:
    usa
    since last summer ive always wondered just how much air is being pulled into any engine in a vehicle at idle or driving speeds.

    i was messing around with hydrogen production just trying to see what i could do with it, anyhow, one of the things i had to use was a jar or something to hold water in. (about a gallons worth) from this jar was ran a tube into another smaller jar filled with about 2 cups of water then a tube running from it to either an intake line or just above my carburetor. (70f100 truck)

    i tried running the tube to above my carb and didnt get any noticeable results, so i thought ild just hook this same tube to an unused 3/8 vacuum plug on the spacer below the carb.

    what i failed to realize was just how hard an engine sucked in air. the jar i was using wasnt made of strong enough plastic because when i started the engine (302), without giving it any gas at all (650rpms), it sounded just fine about 2 seconds and before i got both feet on the ground after exiting the cab, the engine started to slow down and then stop. this all happened in around 2 seconds. before i looked at everything i assumed that it was a vaccum leak or somehow something like that went wrong. when i looked at everything, i turned to look at my water jug ( almost a gallon) , and all but a cup of it was GONE and the jar was flat as a pancake!

    thankfully i didnt get hydro locked.

    in just 2-3 seconds, at idle, at 650rpms, if water could be subed for air, ....see my point/question?

    so how much is going through at 2500rpms or even higher?



    lol
     
    Last edited: Feb 20, 2009
  3. jnaut

    jnaut Full Access Member

    Messages:
    2,237
    Likes Received:
    0
    Joined:
    Apr 17, 2008
    Location:
    Seattle

    No, it's not RAM air, it's air moving at a given velocity producing what is called dynamic air pressure, not static air pressure.

    Look, here's the deal with this scoop/ram air thing. This has been one of the most scientifically debunked concepts in the history of automotive technology, but it just won't die. And the reason it won't die is there's just some mysterious badassery about having a big scoop on your hood with which you just have to believe you're getting a big horsepower boost. The first time I saw that jeep liberty hood scoop, I nearly peed myself. Don't get me wrong, I love a big hood scoop. But any (albeit minor) performance gains you're getting have nothing to do with 'ramming' air into your intake, they're coming from a CAI effect.

    Again, re-read the f1 tech site. We *want* very badly to believe that the scoop on the formula 1 car is 'ramming' air and so HAHA! PROVEN! But sadly, I'm going to take the Formula 1 engineers word on the subject... it ain't ram air.

    I don't think anyone is a bad person, ignorant, less intelligent for believing in RAM air. Decades worth of various manufacturers (including Pontiac) have been using the 'RAM air' concept, and it's hardened up like cement and it's very hard to chip those concepts away.

    This discussion is very popular on car forums. Here's a link to another back-and forth. http://www.allfordmustangs.com/forums/4-6l-tech/18409-the-ram-air-myth.html

    Let me highlight one of the posts:

     
  4. 501

    501 Full Access Member

    Messages:
    452
    Likes Received:
    0
    Joined:
    Jan 20, 2008
    Location:
    Michigan City, Indiana
    Whatever it's called I think I'll take my chances and buy one. I think LTT has a great idea and I'm willing to give it a chance.

    Thanks LTT for working on and creating something new for the KJ! I hope the 02-04 version is still going to be made because I would love one!
     
  5. flair1111

    flair1111 Full Access Member

    Messages:
    847
    Likes Received:
    0
    Joined:
    Jul 10, 2007
    Location:
    usa
    i see your point. good post. cold air does make a diff and thats why i ordered LTTs kit.
     
    Last edited: Feb 20, 2009
  6. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    Tommudd was going to work on a mock-up for the 02-04 models, but no word from Tom on this yet. But if anyone else wants to play around with ideas over the weekend, feel free. Just get some cardboard and duct tape and fab up one that will fit on the 02-04 models. Then if you just send it to me, I will take all the measurements from the mock-up, model it in CAD, tweak it and round off all the sharp corners and print a 3D prototype to try. Same offer applies for any KK's out there that want to make a stab at this.
     
  7. trail rated

    trail rated Full Access Member

    Messages:
    138
    Likes Received:
    0
    Joined:
    Jan 7, 2009
    Location:
    Plant City, FL
    Here is what I think:

    At 60MPH and slight throttle there might be a slightly positive pressure at the bottom of the air box (before the filter), but that's probably as far as the air will go on its own.
    Sure, if you have a giant scoop then you might get a little more air but nothing that will change the performance.

    Do this experiment: Put your hand into the stock intake snorkel (engine running) and pull the throttle linkage. Do you see how much air that thing sucks in? Imagine how much air the Jeep sucks at WOT.

    The only real place the ram air intake helps is in keeping the temps down which may slightly improve performance (you won't really notice it).
     
  8. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    Installation Instructions

    Well, I installed one of the new models on mine today. Took a few pics. I figured I would post the details on installation here for future reference to anyone that gets one. Maybe this will help someone.

    Here is the front of mine with grill removed. I also popped the fog light out just to make sure the wire plug didn't get in the way.
    [​IMG]

    It was a pretty tight fit to get the 3" aluminum tubing thru without bending a flat along one side, so I cut away just a little from the flat piece on the left.
    [​IMG]

    After that, the aluminum went in quite easily.
    [​IMG]

    I then re-installed the plastic push-rivet and the fog assembly. After re-evaluating this today. I really don't think that the two tabs are even necessary. It is such a snug fit, it is not going anywhere, and once the grill is put on, it will hold in place just fine. I may delete the 2 tabs from any new ones that I build since they really aren't necessary.
    [​IMG]

    Here is a pic inside the engine compartment after pushing the tubing thru from the front.
    [​IMG]

    Then I just connected it up to the airbox adapter and tightened down the clamp.
    [​IMG]

    Lastly, I just re-installed the grill.
    [​IMG]

    I think that making that little extra cutout of the plastic and removing the fog light during the routing makes it a lot easier to install. Let me know if you try it again and what results you get. One other thing... Remember to disconnect the battery to reset the computer. That may or may not be necessary, but it is a good practice to make the computer recognize the change.
     
  9. sleeve

    sleeve Full Access Member

    Messages:
    393
    Likes Received:
    0
    Joined:
    Oct 28, 2008
    Location:
    Woodward Ave
    LTT, I plan to mock up [for 02-04's] in April when the weather up here is better.

    Will send them your way in 1 month if I am sucessful.
     
  10. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    Sounds good. Look forward to making a stab at it.
     
  11. flair1111

    flair1111 Full Access Member

    Messages:
    847
    Likes Received:
    0
    Joined:
    Jul 10, 2007
    Location:
    usa
    i tried that a few weeks ago in the main air tube after the filter, then at the air box inlet. HUGE difference pre and post filter.

    the main tube its self has way more suction than i thought. it caught me off guard.
     
  12. SDLiberty

    SDLiberty Full Access Member

    Messages:
    195
    Likes Received:
    0
    Joined:
    Oct 16, 2008
    Location:
    Oceanside, CA
    Well here is what i have for my AI. I used a 3" hole saw and cut a hole in the front lower portion of the stock air box

    Picture is inside air box facing head light
    [​IMG]
    I then cut a 3" adjustable 45 elbow for this piece to fit in the hole.
    [​IMG]
    Using another 45 (painted satin black) to sit behind the grill like so.
    [​IMG]
    Hose clamps and 3" hose of preference to connect the two.
    [​IMG]
    The stock down tube is then filled with foam rubber and i used a little silicon to keep it from falling in to the air box.
    [​IMG]
    After the lift and tires i did loose MPGs and seemed to gain them back after this mod 18-20 MPGs highway. MPGs are est only, give or take how heavy my foot is at the time:D...
    Didn't see any reason to start a new thread And sure don't want to steal your thunder LTT. It's a great mod and thought i would share.
     
  13. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    No thunder stolen. ;) Looks like an easy way to do it too. Someone could use your grill intake idea with my airbox adapter if they did not want to cut a hole in the stock box. Looks good!
     
  14. Uncle Krusty

    Uncle Krusty Full Access Member

    Messages:
    207
    Likes Received:
    0
    Joined:
    Nov 23, 2008
    Location:
    San Tan Valley, AZ
    I like LTT's idea, and for a simple CAI it is just the ticket. good job!

    I live in AZ:cool:, and trust me, I have seen and played the CAI game before. My first outing was with a '69 Ranchero. It had a bit of a problem with vapor locking. My fix was to turn the air cleaner so the snorkle faces the rear of the car. I cut a hole in the firewall large enough the snorckle could be slipped in there, then trimmed the snorkle length down so that it just fit through the hole. This allowed me to take in fresh air from the base of the windshield, just as your foot vents did in older vehicles. vapor-locking solved.

    I had read somewhere this was an old NASCAR trick, and was the fore-runner to "cowl induction" The air at the base of the windshield IS under pressure to some extent. That is what forces it through the foot vent (no fans there).

    As for the whole "ram air" argument, here are a couple thoughts.

    1. 70's model "RAM AIR" equiped cars were carberated. A carberator works on vaccum. If you ever DID achive a positive preasure in the air intake, it would force the gas back through the carberator, and out the bowl vents - Right? That is why the TURBO or SUPER charger must be between the carb and the intake.

    2. When travellling in a car, there is a 1-2" layer of dead air over the body. unless your "scoop" sticks up high enough, ther is no way of forcing the air anywhere.

    I'm not saying a "Ram-AIr" package doesn't help, but I don't think you see much more gain over that of the cooler air alone.

    Try this - hook up a hose from your leaf blower and point it at the opening to the filter box. Don't seal it, as this would not be a true representation of wind entering a scoop, there has to be a way for excess air to back-up and escape. Ideally your idle speed should go up - right?

    (Idiot disclamer - I am not responcible for damage caused by anyone trying the afore mentioned demonstration - Trust me, someone out there will not take this as a joke and duct-tape their Toro to the hood trying to pull 12's in the quarter:eek: - Iv'e worked with some of them in the past...:rolleyes:)

    UK
     
  15. renegade 04

    renegade 04 Full Access Member

    Messages:
    1,432
    Likes Received:
    1
    Joined:
    Jan 3, 2014
    Location:
    Albany New York
    Did you ever build a model for the 02-04 liberty because I am looking to buy one.
     
  16. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    I did not. But on the Gen 1 KJ, the grill scoop isn't really needed. You can use my air box adapter for the Gen 2 KJ and then just route the 3" aluminum vent hose straight in behind the grill slot. I'd be happy to build an air box adapter if you want one.

    Sent from my SPH-L720 using Tapatalk
     
  17. Luke

    Luke Full Access Member

    Messages:
    3,800
    Likes Received:
    0
    Joined:
    Oct 21, 2008
    Location:
    North 'o' Barrie, Canada
    Howdy LTT! .... long time no see :D
     
  18. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    Howdy. Yes. I've been away for a while. Passed my KJ down to my son when he turned 16. Planned to get a Rubicon JK Unlimeted, but then then the gas mileage ghost spoke to me, and I ended up with a new Mazda6 GT that gets 30 on average, 40 MPG on the highway.

    But the KJ is still in the family.

    Oh, and I inherited a 2007 Z06 Corvette. Got the mod bug going on it now...
    [​IMG]
     
  19. Leeann

    Leeann Full Access Member

    Messages:
    2,263
    Likes Received:
    28
    Joined:
    Mar 9, 2013
    Location:
    Maryland
    More pics...
     
  20. long_tall_texan

    long_tall_texan Full Access Member

    Messages:
    437
    Likes Received:
    0
    Joined:
    Oct 23, 2008
    Location:
    DFW, TX
    Of what?

    Sent from my SPH-L720 using Tapatalk