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Airbox Elimination

Discussion in 'Cal 1400 8V' started by jbhotchkiss, Nov 10, 2018.

  1. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    Anyone replaced the airbox with a pod filter? I'm going to dive in and do it this winter, and am interested in the experience of anyone who's gone before me. Thanks!
     
    Last edited: Nov 12, 2018
  2. roadventure

    roadventure High Miler GT Famiglia

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    If you can do this and advise others on how to succeed you will be providing a great service! It is a huge PITA to change the OEM filter with the MG airbox design. My concern would be twofold: (1) will the filter be able to stay dry enough to run in the rain? and (2) whta effects will this have on the already lean OEM tune?
     
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  3. groundhog105

    groundhog105 Cruisin' Guzzisti GT Contributor

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    I think the location of the filter is a pretty well protected area so a pod (if you can find one). Todd could do the tuning for sure.
     
  4. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    Spoke with Todd about this last year when we were fine-tuning his fueling kit on my Custom. He advised that he would work with me on a new map (paraphrasing). I've run pods on other Guzzis (Centauro, v11Sport, 1200Sport) with no wet weather consequences. I have the box out and pod ordered. Pics and pod specs to follow.
     
  5. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    OK - finally got around to finishing this project. Here we go.

    As many of us know, getting to the air filter in the California 1400 is very difficult and frustrating. I discovered this when fitting a replacement K&N air filter as part of installing Todd Egan’s fueling kit. Told myself at the time (two years ago) that I would someday replace the airbox with a pod filter, as was done with other Guzzis in my past.

    Theoretically, a pod filter could be attached directly to the throttle body. That could work, but then you would have to remove the tank to be able to remove the filter for maintenance, or to replace it. Also, there just ain’t much room for the body of the filter in there between the wiring harness verticals, as you’ll see in the pictures.

    I chose to use the stock design as guidance. The stock Cali1400 has a rubber tube clamped to the throttle body on one end, and the airbox on the other. So my approach was to use an aluminum tube in place of the stock rubber tube, and attach it to the throttle body using a rubber coupler/reducer, and clamp a UNI filter onto the other end.

    Here’s how I went about it….

    REMOVE THE AIRBOX
    1. Remove the fuel tank. Don’t forget to release the pressure in the line before attempting to disconnect the fuel line.
    2. Remove the right side cover.
    3. Remove the battery.
    4. Remove the blowby hose from the airbox at the connection on the top left front of the airbox. And while you’re at it, go underneath the bike and yank on the clear blowby collector hose to remove it from the bottom of the airbox. Easier now than later.
    5. Disconnect the airbox from the bracket - bolts on each side up top.
    6. Remove the wiring harness from the bracket thingy - two screws.
    7. Remove the bracket thingy - it will otherwise be in the way.
    8. Remove the bolts that secure the bottom of the airbox to the battery box just below the frame rails on each side. This was a surprise to me as it is not evident in the workshop manual (pages 168 and 169).
    9. Disconnect the tube connecting the throttle body to the airbox - there are clamps on each end. Remove the tube, making removal of the airbox much easier.
    10. OK - now wiggle and cajole that damn thing out of there. Throw it across the garage/shop - and swear at it if you like, as did I.
    Here’s the airbox out of the bike (ignore the UNI next to it, as it is not the one I used)….

    [​IMG]
    airbox.JPG

    ...and the and the void created by its removal…

    [​IMG]
    airboxVoid.JPG

    ...and the throttle body exposed…

    [​IMG]
    throttleBody.JPG

    ORDER PARTS

    Your new intake system will need a rubber coupler/reducer that attaches to the throttle body, a tube to go from the coupler/reducer to a filter, a filter, and some clamps.
    1. The coupler/reducer is 3 inches inside diameter (ID) on the throttle body end and 2 ¾ inches ID on the tube end. I used one from Spectre Performance that worked perfectly - part number 87831. You’ll need a couple of 3 inch clamps (they aren’t included with 87831), so order those as well. Spectre has them.
    2. The tube should be 2 ¾ outside diameter (OD) and should be a minimum of 3 inches long. The longer the tube, the smaller the filter. I wanted to use a bigger filter, so I went with the minimum of 3 inches. I used an aluminum tube from HPS Silicone Hoses - part number AJ300-275. It has a bead roll with a small extension on each end, and I had to remove the extension one end for proper fitment to the coupler/reducer. You can get one without the bead roll, and you won’t have to remove the extension.
    3. The filter needs to have a flange ID of 2 ¾ - I chose the UNI UP-6275AST because of its length, relatively slim profile, and angle.
    An angled tube and a straight filter is an option I did not explore, but would have if the clearance from the highest part of the filter to bottom of the front of the seat was any tighter. You may want to consider it.

    BLOWBY SYSTEM

    Because the airbox goes away, a receptacle is needed for the airbox end of the hose coming off the front of the blowby collector box. Do what works for you - I used a small plastic bottle. Also, I chose to replace the hose and changed the routing of the hose from up from the front of the collector box and then outside the frame and in, to down and inside the frame - plenty of room. I used clear fuel line as replacement hose, as you can see in the pictures.

    Here is the new hose as it comes off the blowby collector box...

    [​IMG]
    blowbyRoute1.JPG

    And then between the cylinders on the left side…

    [​IMG]
    blowbyRoute2.JPG

    And under the plenum and into the plastic bottle I used for a receptacle…

    [​IMG]
    blowbyRoute3.JPG
    [​IMG]

    blowbyRoute4.JPG

    INSTALL YOUR NEW INTAKE SYSTEM


    Now you’re ready to build your new intake system.
    1. Install the coupler/reducer, clamping it to the throttle body flange.

      [​IMG] CouplerReducer_1.JPG

      CouplerReducer_2.JPG

    2. [​IMG] Install the tube, clamping it to the coupler/reducer.

      tube_1.JPG

      tube_2.JPG

      tube_3.JPG

    3. Install the filter, clamping it to the tube.

      UNI_1.JPG

      UNI_2.JPG

    4. Install the bracket and attach the wiring harness, as seen above the UNI in the previous 2 pictures.
    5. Install the battery.

      UNI_3.JPG

      UNI_4.JPG

    6. Install the side covers and the fuel tank. Note that the UNI filter is accessible for removal via the clamp bolt between the bracket and wiring harness.

      UNIaccess_1.JPG

      UNIaccess_2.JPG

      UNIaccess_3.JPG

    Tight fit, but now you can access the filter much easier.

    You’re finished! Unless your left center spark plug wire looks like mine did.

    SPARK PLUG WIRE
    The center spark plug wire on the left cylinder was pinched between the blowby collector box and the cylinder, badly damaging the protective sheath on the wire. To remediate the situation, I widened the gap between the blowby collector box and the cylinder.

    1. Remove the bolt that attaches the side of the collector box to the tab on the frame.
    2. Replace with a longer bolt through the frame tab and nut (I used a nutsert type of thingy) on the inside of the tab that creates sufficient gap between frame tab and collector box, thereby increasing the size of the gap between the collector box and the cylinder.
      An alternative is to use the original bolt and some spacer washers and screw it into the threads on the collector box.
    3. If the spark plug wire sheath is damaged, wrap it with some good tape, or otherwise protect it.
    MERRY XMAS!
     
    Last edited: Dec 27, 2018
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  6. groundhog105

    groundhog105 Cruisin' Guzzisti GT Contributor

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    Great job on doing away with the airbox. How does it run? That would be the big question?
     
  7. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    Don't know yet how it runs - awaiting warmer, drier weather here on the wet side of the Cascades in Oregon. Guessing it will run the same as before or better, as the airbox lid had been opened up and a K&N filter installed as part of installation of Todd's fueling kit. I say maybe better because of adjustments to two valves on the left cylinder - a tight exhaust and a loose intake.
     
  8. GT-Rx®

    GT-Rx® Administrator Staff Member

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    Jeff, make sure you send me the PC-V file, and we should do a static tune as well. Ping me direct email.
     
  9. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    Roger that, Todd.
     
  10. groundhog105

    groundhog105 Cruisin' Guzzisti GT Contributor

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    Is there a sensor in the air box that needs to be dealt with?
     
  11. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    The sensor is in the plenum, to which the throttle body is attached. No sensors in the airbox.
     
  12. groundhog105

    groundhog105 Cruisin' Guzzisti GT Contributor

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    Ok, I think I like where this is going.
     
  13. jbhotchkiss

    jbhotchkiss Cruisin' Guzzisti GT Famiglia

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    Went out for a spirited ride on the Cali yesterday - oh boy oh boy oh boy! I swear it is running better, probably due to the left side valve adjustments. Little bit more intake honk, and much better very slow steady-throttle cruise (as in putting through a small town with 20 mph speed limit). And I said spirited, didn't I? When I passed a pickup towing a horse trailer that pulled out in front of me, reminded me of grabbing a bunch of throttle on my dear departed Centauro. Gonna download the map and send it to Todd and see what he says. But I am a very happy boy.
     
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  14. groundhog105

    groundhog105 Cruisin' Guzzisti GT Contributor

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    This is sounding good
     

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