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Airbox Elimination

GTM®

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GT di Razza Pura
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Chris was posting on the V7 thread, so I merged it with this one on air box elimination. Again, the side panels on a 1400 tank do NOT need to be removed for anything unless being replaced or (re)painted.
 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
15
Location
MIfflintown, Pennsylvania
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)….

airbox-jpg.16119

View attachment 16140

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

airboxvoid-jpg.16120

View attachment 16141

...and the throttle body exposed…

throttlebody-jpg.16121

View attachment 16142

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...

blowbyroute1-jpg.16122

View attachment 16143

And then between the cylinders on the left side…

blowbyroute2-jpg.16123

View attachment 16144

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

blowbyroute3-jpg.16124

View attachment 16145
blowbyroute4-jpg.16125


View attachment 16146

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.

    couplerreducer_1-jpg.16126
    View attachment 16147

    View attachment 16148

  2. couplerreducer_2-jpg.16127
    Install the tube, clamping it to the coupler/reducer.

    View attachment 16149

    View attachment 16150

    View attachment 16151

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

    View attachment 16152

    View attachment 16153

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

    View attachment 16154

    View attachment 16155

  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.

    View attachment 16156

    View attachment 16157

    View attachment 16158

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!
I am alittle late to the party :). I have a 14' california 1400 and I am following your detailed material list to duplicate this airbox removal. I have a question. A local pipe shop is willing to make me a bent pipe ( cut to angle and welded because it is so short ) . Could you look to see what angle would be ideal and once presented on an angle would the 3 inches still be ideal. I see the 15 degree boot on the uni filter still does not have the filter square to the battery. I will also attempt to determine a possible ideal angle. One idea I had was to have them make it the 15 degree and then using the same filter I could pivot to make a complex angle. Ideally it would be nice to come out dead straight with relation to the battery to provide more options for filters that have a straight boot. For anyone that is interested BMC ( BMCFBSS70-128 )makes a similar size conical filter that has the paper style filtration media in a straight boot. weather or not the more ridged form factor would work for the close fit in these bikes I am not sure.
 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
15
Location
MIfflintown, Pennsylvania
Chris was posting on the V7 thread, so I merged it with this one on air box elimination. Again, the side panels on a 1400 tank do NOT need to be removed for anything unless being replaced or (re)painted.
I appreciate your clarification on the side panels and as I am getting used to this forum as a new member I did not realize I was in the V7 forum :) so thank you for moving my posting here.
 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
15
Location
MIfflintown, Pennsylvania
Wel the the airbox is out. Wow is it tight in there. What a wonderful thing to have it removed. Now I just have to decide weather to proceed as Gavin has done or the method employed by jbhotchkiss. both are great solutions just a matter of a decision I suppose. If it is of any help to anyone I have found that the UNI UP-6300AST I believe is the equivalent of the Euro spec filter that Gavin purchased. It is 6 inches in overall length and has a angled 3 inch ID flange It would mount directly to the throttle body inlet and present close to flush with the start of the airbox cavity. I must credit "whatthe" for his kind assistance today in verifying the dimensions and setup which he has in place which is in fact a match to the filter direct fit method used by Gavin.
 

GTM®

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GT di Razza Pura
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Wel the the airbox is out. Wow is it tight in there. What a wonderful thing to have it removed. Now I just have to decide weather to proceed as Gavin has done or the method employed by jbhotchkiss.
Indeed, and both have the devices fitted/linked below to make this MASSIVE revision to fueling required to make that work. Don't fool yourself otherwise.

 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
15
Location
MIfflintown, Pennsylvania
Indeed, and both have the devices fitted/linked below to make this MASSIVE revision to fueling required to make that work. Don't fool yourself otherwise.

thank you very much. I will take a look at this product. Any technical questions I may have is it ok to pose them here or should I do that via PM.
 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
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Location
MIfflintown, Pennsylvania
I am taking the liberty of asking these questions here as a Pm this long did not seem to work

Todd,
regarding your recommendation of upgrades in keeping with my airbox removal. I have a couple questions if you dont mind. ( I have read extensively on this forum before writing to you.
1) with 20K on the clock no sign of H pipe cracking. Is there a way to determine if this maybe has your H pipe already on it ?
2) Your full exhaust system I am assuming is louder than the stock system ?
3) The H pipe that you make when mated to the stock mufflers will not crack ? ( I have read that the stock mufflers are heavier than your mufflers ? )
4) The tuning system that you have looks very good but I am forced at present to stretch my budget. Do you feel that just doing the intake air pod necessitates the tuning ?
5) is it ok to use your tuner with the stock exhaust ?
Thank you for your time
 
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GTM®

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GT di Razza Pura
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regarding your recommendation of upgrades in keeping with my airbox removal. I have a couple questions if you dont mind.
Chris, I am not accessible direct (PM or email) for questions like this normally, so please don't address me personally here. That said, I'm happy to answer here if I see it. Only product purchase questions can be emailed via the GTM Store. We do not answer tech support questions via email.

1. Just look at the thread here on the H-pipe to identify mine; https://www.guzzitech.com/forums/threads/gtm-c14-h-pipe-header-info-instructions.17518/
2. Yes. Links are on the product purchase pages.
3. Correct.
4. This is EXTREMELY well covered on this Forum. Yes.
5. Yes. Also well covered in this section.
 

Chris_

Just got it firing!
Joined
Jan 18, 2023
Messages
15
Location
MIfflintown, Pennsylvania
I purchased in haste it appears the 3" to 2-3/4" adapter and 2 clamps from spectre performance and I have now elected to go a different route so if it would be a help to anyone I would be happy to sell it at a very reasonable price. In factory box and packaging. Pm if interested . thank you
 
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