Pull the seat, pull the gas cap and gas cap panel. Pull the side panel. Remove back airbox cover. Remove filter. Pull seat, easy enough. Pull gascap and the panel. This takes four torx screws. Pull side panel. This is the worst part. remove top screws, remove bottom screws and screws from the front on the inside. The front snaps into place and is the bugger to get apart. A butter knife and some gentle prying as you work the red panel. Then it lifts out of the rear white piece with little effort. Since an earlier mod to airbox was done, at this point the rear top part of the airbox removes with 3 torx. Now just undo the hose clamp and remove filter Clean filter and revers order to install. I haven't tried it, but if I do not put in the front screw of the cover, removing the side panel may not be necessary to change the filter. I drove it today, without panels and it is loud. Most likely I will seal the seam with some sort of tape. Then with the panels back on it should only be slightly louder. 2 photos up, you can see the extra hole added to airbox for intake.
X2 - also any notable performance/characteristic changes. You mentioned sound, like much louder than stock? Source for parts?
Those that have changed out the filter note that the air box is noticeably noisier but not annoying. I really need to do this mod as it is super dusty on the gravel roads I travel. I pulled my pre-filter and stock filter yesterday and there are wisps of dust trails in the air box. Not acceptable.
I just got home from 100 mile trip. I'm not happy. I banged my knee, the bike seems to have picked up a vibration and the sound of the box is not the same as before. I did have my tank bag on, but I have drilled additional holes in the side and front, probably not necessary. As for performance, I doubt there is any increase at lower rpm, and at higher RPM, there may be a slight uptick. One note: I have not installed any spoofer yet. I am going to run out this tank and get a mileage, then change the IAT to the eruption and run another tank. The bike stuttered once, and has the usual doggyness monster. Yeah, I lied, I'm happy, the weather is good here, around 80º and up into the hills and canyons it got a bit chilly. As far as removing the airbox for the mod, you may not have to do that. If you are careful and have a good hacksaw blade, you should be able to cut the top hatch out. The toughest part will be along the gas fill part of the tank. If you do not cut into the overlapping seam, I think removing the three screws, and prying might break it free. This plastic is pretty brittle. Be very careful not to cut the gas tank. That is over 200 bucks, the airbox is about 35 bucks. (I have a new on on order) As far as hogging out the bottom hole, you have to remove that rubber grommet that seals to the throttle body. The way mine lined up, I did hog out the hole, but then had to make a big washer to keep the box from resting on the fuel rail. If you could surgically remove the rubber piece, from the top, and leave the rest behind to center the box and keep it from dropping, there seems to be enough left on the throttle body to clamp to. This photo shows the basic chop on the box. I used slightly different variations of what you see, everything is interference fit. The silicon elbow might be the way to go, I just worry about the heat of AZ and that hose collapsing. This elbow is a drainpipe trap, cut to fit and ground down. This is a bad shot of the big washer I made so the airbox would not push down too far. Again, I will mention that if you can cut the top of the rubber piece flush with the top of the inside of the box, you will save yourself alot of trouble. Below is the magic part, Lowes about 8 bucks. You can only buy it as the assembly, they do not sell the elbow separate. The drain elbow is nice, as it it designed to flow water the same direction the air will go. On the version I am using, I kept the female part on and added a small section of pipe for the Uni to fit onto. Please note, that in the stock form the OD is just a bit big. I took my belt sander and ground the OD down and then but a grove in it to keep the hose from sliding off.
What you need for parts? The elbow Lowes about $8 a 2" drain???? don't quote me, I just match things up. Some 2 1/4 radiator hose A couple more clamps A short piece of abs for the filter to hook to. A bit of patience. A uni filter. UP-6229AST 2 stage pod. I used the 2.25x6 with a 15 degree angle. You may be able to use the 4" one if you think it is big enough flow. My bike shop got it as cheap or cheaper than online stores. About $18 I think. I am not using the pre filter at this time, it fits but real tight. You will need a file/rasp or belt sander to bring the OD down to closer on the abs drain elbow. Time consuming and tedious. But I would be willing to bet this could be done in an afternoon. Pull the left sidepanel and center panel, hack away carefully, remove the three back screws, cut rubber grommet with razor knife to flush, hook up hoses elbows and filter and button back up. Sounds easy once it has been done. BE WARNED, every tolerance is interference fit. A little one way or the other and the lid does not seat well. This is from the indent in the airbox hatch, to make room for the screw that hold down the center panel at the rear left point. You could cut that nub on the hatch and have a hole in your box, and it will fit easy. I opted to remove a small piece near the fill neck to get a little more clearance. Gained about a 1/4 inch I have this left over, it works, but you would need to add a short secton between it and the filter to make the clearance without cutting the nub. EDIT: In my final iteration, I use the elbow keeping the female part and adding a short section of abs to push the filter toward the front of the bike. We used the elbow pictured on Marc Pod Mod in video.
Everybody who runs in the dirt needs to do this. The amount of dirt and sand that got past the filter, and past the seams is not acceptable under any circumstance. The airbox has a design flaw. I would love to take sandpaper to the engineer who designed this so they can get a clue.
Thanks so much for this great info. Not crazy about more noise, but keeping the crud out of the motor is #1! Great job, be interested to see if the ER smooths things out.
More pictures. You can get an idea of where to cut. I do believe this can be done while on the bike. The rubber grommet that seals the box to the throttle body, also holds the airbox from settling down, should you put weight on the front of the seat. You would leave this part on the TB, to support the box. The fuel rail is removed, and the clearance is small. (BMW f650 TB) From the top, it looks possible to trim off the grommet flush with the top of the airbox. I see two possible difficulties with this. The one is getting the knife into the close quarters on the filler neck side of the airbox, and the second issue to anticipate is if you cut the rubber flush, there will be nothing really to hold the grommet in place, which might force the airbox up. There is rubber between the edge of the box and the TB and that may need to be removed, at least a small portion. I had the box removed, so I just built a washer to hold it off of the fuel rail. I also drilled a small drain hole near the AIT. The only difference I find on the TB from the BMW is the vacuum tap. You can see it at the bottom center of photo. On the TR it goes forward, on the bmw it goes down. Hope somebody tries the mod without removing the airbox and documents well. My pics suck. I can't get the auto exposure to function proper. Look at the amount of dirt in the box, do you really want that grit in you motor? 1500 miles and it was cleaned a little bit. That is grit. Airborn sand paper. You need to do the mod.
Somebody was asking about performance of the filter mod. I found a pic of my first dyno run with stock airbox and modified single can from a raptor. No cat. Compare that to the green line, (airbox mod) of the second run done a couple days ago. Then the bottom should be a bone stock run. Seems that the airbox mod may cost a pony, but nets some nice torque gains. Bear in mind the first run (pic of dyno screen) was done in 100º weather on a totally different dyno. This last one should be a stock tr650 pulled from somebody else, I believe comparing the pc5 performance gains. [/QUOTE]
This weekend I had the chance to take a movie of cutting the airbox while installed on the bike. Movies below. It was easier than I had expected, especially removing the rubber grommet. I do not have video of the grommet removal. I initially cut the top part of the grommet and started pulling, and to my surprise it pulled right out of the airbox. It may come out by just pulling hard. Maybe just an nice prybar underneath. This first video is of cutting, you will need to remove the center and left panel. This next video starts with cracking what was not cut with the hacksaw. It breaks rather predictably, don't rush or get carried away and you'll be fine. Both video were on the fly, never done this before and not edited. As I mentioned earlier, you may get lucky and be able to pull the grommet up starting on one side and not even have to use a knife or blade. In photo below, you can see where I started to cut, but then pulling I was hoping it would just tear, but to my surprise, the whole thing came out in one piece. Check out the dirt in the TB, you can see a bit of the plastic. Nothing a vacuum won't get. We did take a good shop vac with a nice nozzle and brushed all the dirt and mud out of the TB. Then a small hole, maybe 1/4 inch was drilled, to drain the airbox should water or snow get in. This is right behind the AIT. Just look and examine what works best for you. You can drill down, or from the side like in the photo. Remember to remove your stock filter from up front to reduce restrictions of air. And we did cut a relief for the fuel rail, for extra clearance. This was accomplished by cutting from underneath for most part, then cracking what was not able to be cut. Use discretion and be careful not to disrupt things hiding underneath. The box flexes easily, so it can be lifted quite a bit for access. When yo put the screws back in for the hatch, it strengthens this part back up. Remember, that is only 8K miles and looks like an engine with over 100k. The dirt and silt in the box was mind boggling. This bike did have a K&N filter installed at some point. I have read about some other airbox mods that may be coming into the market, but those only seem to address the crappy fitment of the filter, and not the case leaks, internal design problem and now the newly discover grommet to TB leaking. There is no clamp on the stock rubber connector, there is a clamp on the TB connection when you do the Njoy Uni Pod filter Mod. I sincerely hope this helps those on the fence about the air box mod to get it done. Your bike will love you for it.
Great write up. I can't believe how much dust and dirt in and around the throttle body. Njoy did us all a favor by coming up with his intake modification.
Thanks Baddrapp. I think he lost one engine and had to fight warranty. But the mod made sense. I would love to see some development on a little better elbow using the 3D printers.
IMHO it would really be ideal if there was a filter that would sit atop the TB and just bolt directly on without an elbow. I searched a few days looking for one but none offered the prefilter I wanted.
Followed mag00's you tube video (thanks for the video!) and did the pod mod this weekend without removing the air box. It was pretty easy. I carefully cut away the rubber grommet flush with the inside bottom of the airbox. Couple of observations/questions: I removed the red pre-filter from the UNI filter. It just did not seem to fit with the pre-filter installed. Have others been removing the pre-filter and is this a concern at all? I did not make any changes to the crank case filter, but I removed the stock paper filter. So now the stock crank case filter is more exposed to dirt without the stock paper filter. Is this a problem I should address and if so will I have to pull the air box anyway? Here is a picture of the dirt in the air box and throttle body before I cleaned it up.
I'm thinking to just add a small clear inline fuel filter to the breather line (insurance). I haven't really worried about the breather, it pulses air, does not consume it. If anything their may be a positive net pressure, thus really no need at all for a filter. Somebody has added the filter while on the bike, I think they just had to drill a hole to access the clamp to tighten the new filter into the chamber where the old filter was. Yep, removed the pre filter also.
I use the pre-filter as Arkansas backroads are really dusty. No biggie, no difference in performance and the prefilter gets cleaned more than the main Pod due to it's intended use. Here is where I located my new Crankcase Filter. Not sure why the text on the next picture is upside down but you will get the gist of it.
After way more hours than I want to admit (and my employer definitely doesn't want to know about) catching up on the advrider thread, I found the 3D printed solution is "complete". (Is anything ever truly complete?) Details for having the 3D printed Uni filter flange made is here: http://advrider.com/forums/showpost.php?p=24052015&postcount=3913 I know there are huge advocates for the pod mod, and there is no doubt it allows greater airflow. But the 3D printed/sealed airbox option has the "factory" finish that I am (and likely others are) looking for. Just throwing this up on this, as I hadn't seen any updates carry over onto here.
