Finally getting around to modifying the air intake process to make it more efficient and easier to clean.  The areas I ride in in Idaho are very dusty.  Cleaning the air filter after each ride is getting old.  Working with the stock air box is equally frustrating.  I have been running a Uni Filter since day one thanks to the advice of this board.  I have read and studied all the snorkel mods I could find and think I have come up with a combination of everyone's good ideas into one that will satisfy my needs and protect the motor.  Here is what I plan and would appreciate any feedback:

I plan to take off the stock air box but use the box cover to help deflect debris from the back tire.  I will run tubing straight from the carb, into the bed via the back wall (like NMK did).  then I will run it up and connect a carbon fiber air filter canister (again, like NMK) with a Uni filter in it.  From there I will run it up to the lower part of the roof, add a 90 degree turn and run it toward the center indent of the part of the roof that slops down and attach another preliminary filter (not oiled, maybe an automotive rectangular one) held in a salvaged air box from a small import.

I have not taken anything off yet and don't know what size to use to connect to the air box.  I have seen some use 2 inch schedule 40 PVC, Street 90's, NMK uses 3 inch aluminum turbo tubing (send me three feet please) and silicon flex tubing.  I have found several carbon fiber filter canisters online that come with size adapters and am tempted to order two.

So, feedback?  Sizing recommendations for best breathing possibilities?

Thanks in advance.

[2015 Z Force 800 53/Trail EPS]

2" is probably Ok but 2.5" is what comes out of the OE airbox. The OD of the OE filter adapter is 2.25" so..the best thing to use really is something larger then that because of the distance it needs to flow..so 2.5" at least IMO. I just used 3" after that because of parts and filter options available...plus it looks tougher..lol...and the air moves slower through the first filter which helps get everything.

2" is probably Ok but 2.5" is what comes out of the OE airbox.

Do you happen to know what the Carb intake OD is?  I'd like to clamp on to that.  2 inch seemed a bit too small to me as well.  I am wanting to go 3 inch as you did.  Just got to find all the parts.

[2015 Z Force 800 53/Trail EPS]

2" is probably Ok but 2.5" is what comes out of the OE airbox.

Do you happen to know what the Carb intake OD is?  I'd like to clamp on to that.  2 inch seemed a bit too small to me as well.  I am wanting to go 3 inch as you did.  Just got to find all the parts.

The manual tells the MM of the throttle body. Just convert that..but that will be the ID not OD of the flange. But just guessing I would think the 2.25" filter flange would slip right over it like it does on the adapter tube. You sure don't want any leaks or chance of it coming off. Also remember the engine is rubber mounted so it does move some..make that a rubber fitting long enough for some movement.

2" is probably Ok but 2.5" is what comes out of the OE airbox.

Do you happen to know what the Carb intake OD is?  I'd like to clamp on to that.  2 inch seemed a bit too small to me as well.  I am wanting to go 3 inch as you did.  Just got to find all the parts.

The manual tells the MM of the throttle body. Just convert that..but that will be the ID not OD of the flange. But just guessing I would think the 2.25" filter flange would slip right over it like it does on the adapter tube. You sure don't want any leaks or chance of it coming off. Also remember the engine is rubber mounted so it does move some..make that a rubber fitting long enough for some movement.

I agree and was thinking of using the stock boot off the throttle body and go from there.  Should be fun to get in there and start the work.  My wife is surprised I haven't had the whole thing apart yet.  That's typically my method with each new motorcycle, complete take down and re-assembly (grease everything right, check fitment, aftermarket parts add on) all before any dirt hits the bike.  This thing has been too much fun getting out and exploring the great State of Idaho.

[2015 Z Force 800 53/Trail EPS]

2" is probably Ok but 2.5" is what comes out of the OE airbox.

Do you happen to know what the Carb intake OD is?  I'd like to clamp on to that.  2 inch seemed a bit too small to me as well.  I am wanting to go 3 inch as you did.  Just got to find all the parts.

The manual tells the MM of the throttle body. Just convert that..but that will be the ID not OD of the flange. But just guessing I would think the 2.25" filter flange would slip right over it like it does on the adapter tube. You sure don't want any leaks or chance of it coming off. Also remember the engine is rubber mounted so it does move some..make that a rubber fitting long enough for some movement.

I agree and was thinking of using the stock boot off the throttle body and go from there.  Should be fun to get in there and start the work.  My wife is surprised I haven't had the whole thing apart yet.  That's typically my method with each new motorcycle, complete take down and re-assembly (grease everything right, check fitment, aftermarket parts add on) all before any dirt hits the bike.  This thing has been too much fun getting out and exploring the great State of Idaho.

Right..sometimes for me it's hard to "Stop tinkering and Start riding". But for us here most of our riding areas are close until spring so...the "tinker" is on...lol. I'm making some seals for my doors right now cause the Russian doors have a big gap around the bottom and back that the front tires just pure dirt and dust in..piles up on the seat and floor an inch thick in about 10 miles of road running. Always something

I'm making some seals for my doors right now cause the Russian doors have a big gap around the bottom and back that the front tires just pure dirt and dust in..piles up on the seat and floor an inch thick in about 10 miles of road running. Always something

That's a "next" project, too.  My doors do the same.  I'm looking at some type of door skirt to help seal off the dirt.  I'm also working on plugging all the small holes in the front firewall and footplate area (under the dash, etc).