Designing A New Air Box

[ncologerojr]

*I am no engineer, so this is going to take some trial and error...technical input positive/negative is welcome.

It seems that if you want the most out of your bike an air box is the way to go. There is no sure way around it. Unless you want to spend some serious cash on some high end carbs, and I don't. But, the stock air box is just plain ugly. I painted my tank Porsche forest green metallic, had my seat covered with beautiful stitching, re-finished my frame satin black, etc... I don't want to stick the ugly air box back on, but I don't want to sacrifice performance/drivability either.

I tried a gsxr carb swap, which was tremendously better than stock with pods. But, they still showed the common problems associated with running pods and cv's.

So I decided to make an aluminum air box. Personally, I would rather have a handmade, tig-welded, aluminum air box tucked under my seat that the stock plastic part. My first attempt looked great and helped some, but ultimately came up short. Using the emgo pods as filters was a mistake. The inside area did not flow enough air to keep up with the engine at high rpm. There was no real space for air to "settle". (See my tracker build thread for more pictures).



So, I began looking at stock air box designs more closely. I found one thing in common with most; air enters high, travels down below the carbs (I'm assuming to settle a bit?), and is then pulled up and through a velocity stack. After noticing that I thought up a few modifications for my current design to make it closer to the stock configuration.

-air will enter through a 3" inlet using a k&n cone designed for auto intakes, and then travel down and below the carbs.
-I will add a hopper shaped collector below the carbs.
-I'll make smooth aluminum stacks from the box into the carbs.

A quick design sketch (sorry for the drawing, I'm way out of practice)

 

[xb33bsa]

looks great !
i hope it works well

 

[ncologerojr]

looks great !
i hope it works well

Are you serious? Sarcasm is sometimes hard to read...lol

 

[tonandaquarter]

Your drawings are fine, stop bragging

And thats a superb airbox, im wondering why this isnt a common thing allready. (buisness start up idea)

 

[ncologerojr]

Your drawings are fine, stop bragging

And thats a superb airbox, im wondering why this isnt a common thing allready. (buisness start up idea)

Thanks. I used to sketch daily, now almost never so it looks like crap to me lol.

Thanks for the input. I'm going to start working on a cardboard mock up.

 

[oldskool]

you can take aluminum or copper tubing to make extensions for the pods,at low end n cruising they are too close and disrupt airflow. the extension will help to create more velocity n give you a good idea of how far the air box should be away from the carbs.

 

[xb33bsa]

Are you serious? Sarcasm is sometimes hard to read...lol

yes i am serious
i do think it would be even better if larger overall and with the oem rubber stacks on the catbs, but you are definately headed in the right direction !!
and you do real nice fab work

 

[ncologerojr]

Thanks for the support guys. Here is a quick mock up. I made it as large as possible, if any bigger it would have to be two pieces to remove/install. The filter will mount where the front circle is drawn.
There is not very much room to adjust runner length, so I am going to make them as long as possible. If I could use the stock runners that would be ideal, but I may have trouble securely mounting them. I may have to make runners from aluminum tube, fluted if possible...

 

[M.B Co]

Interested in the outcome. The idea and execution will be great for sure.

 

[ncologerojr]

Interested in the outcome. The idea and execution will be great for sure.

Thank you, I'm interested as well...lol

 

[oldskool]

lookin good n nice fab work

 

[irk miller]

Not coming at it from an engineering perspective, but I question if you're improving the visual aesthetics. I recognize the desire to go with the open triangle. I enjoy it and went with it on my bike. But the stock air boxes utilized the lines in the frame (the triangle) to help determine their shape. Have you considered giving ends of the air box a more designed and considerate form? Right now you have a very utilitarian hopper shape. Filleting the top edge lends somewhat to a aesthetic focus, but the shape is still awkward, rigid, and boxy. Nowhere else on the bike is there such boxy forms, except maybe the battery tray.

 

[mydlyfkryzis]

I think you need to consider a rear "Fender" at least some tin between the fork rails just in front of the tire. The dirt kicked up by the tire will quickly clog the large cone filter.

A reasonable execution of a single air box with a single filter. The later NH 750 airbox is somewhat similar to that. It has a single filter, into a relatively large plenum.

I like what you are doing there.

 

[Ribo]

signed up...I was thinking about doing something very similar but I'm at least 6 months away from starting this part of my project. Looking forward to seeing how this turns out, I think you're on to something here that a lot of people will be interested in - once they've tried and failed with their pods.

 

[ncologerojr]

Not coming at it from an engineering perspective, but I question if you're improving the visual aesthetics. I recognize the desire to go with the open triangle. I enjoy it and went with it on my bike. But the stock air boxes utilized the lines in the frame (the triangle) to help determine their shape. Have you considered giving ends of the air box a more designed and considerate form? Right now you have a very utilitarian hopper shape. Filleting the top edge lends somewhat to a aesthetic focus, but the shape is still awkward, rigid, and boxy. Nowhere else on the bike is there such boxy forms, except maybe the battery tray.

I absolutely see what you are saying, and have considered it myself. I decided to stay with a purely functional form for a few reasons. Fist off, I'm not 100% sure that's it's going to work. It would almost double the fab time to try and improve aesthetics, and then could not work.
Second, keep in mind that when sketched/mocked up it looks very angular with hard edges. But once you start adding the welds and bending the aluminum everything takes a "softer" look.
Lastly, I think that the angular/aluminum contrast to the rest of the bike adds a bit of a sporty or race touch to the overall look of the bike. It makes it obvious to the the non-enthusiast that the part serves a function. They might not know what it does, but the raw aluminum and welds lends itself to a performance look.

...or it will look like crap, and I'll have to make a better looking version 2.0...

 

[ncologerojr]

I think you need to consider a rear "Fender" at least some tin between the fork rails just in front of the tire. The dirt kicked up by the tire will quickly clog the large cone filter.

A reasonable execution of a single air box with a single filter. The later NH 750 airbox is somewhat similar to that. It has a single filter, into a relatively large plenum.

I like what you are doing there.

Thanks, I agree and plan to add fenders front and rear. I just haven't made them yet. The bike is only about 80% complete, but I want to get it running correct before moving forward.

 

[ncologerojr]

Also if this seems to work I would be willing to test it out on a dyno to get real results.

 

[Big R]

Great work man.

 

[SaltCityCafe]

I'm in to see where this goes

 

[Heavies]

Looks great, I think it'll work out just fine.

I have a similar idea as well and hope that it will work. I too have a little while before I am ready to start on this part of my project. Thank you for sharing and hope to see great results with your design.