Discussion Pod Filters are the best...

Youtube keeps recommending pod filter videos to me now, even tho I never searched it there, big data knows I seek pod answers LOL
Two videos have suggested there may be a "work around" to the downside of pods on a CV carb. Neither likely as well "tuned" as oem airbox, but functional at least is the claim.
One method seems to be adding a washer inside the pod to restrict flow back to stock & also keep some vacuum in the carb inlet, another utilizes a metal shroud outside the filter, or a tube inside, to achieve similar airflow restriction. Some say a used beer can shroud is ideal & can be cut or trimmed to the best airflow balance easily.
& a 3rd possibly most "precise" method involves adding a washer mounted on a shaft in the intake path so the user can adjust the intakes airflow & pressure externally via the shaft, much like a throttle plate, only just for intake airflow itself. All of these methods need dialed in with engine run time, reading plugs etc. You would think once an good happy medium is found (if its even possible) the user would make a more permanent restriction from something other than washers or beer cans but does this sound like a way to successfully simulate the airflow & vacuum of a stock airbox ? I think the outer shroud method could really help with turbulence from wind, the washer on a shaft idea could really dial things in, & even be used to correct for altitude in a pinch on an off road bike ?

So, any thoughts on attempting to correct pod airflow characteristics by restricting the flow ?
(Of course this is all assuming the pod is LESS restrictive than stock) Some have suggested pods may have less filter surface & airflow. After calculating the surface area of the pod on my particular cafe project vs stock they are both very near in surface area at approx 1500mm2 so too restrictive should not be an issue.

 

I think some missed the intent of pod filter in my particular build....not doing it for more airflow/power...its a 13hp 200cc bike LOL
Its strictly for the looks ! while performance is great & all, looks do mean something
Stock airbox is old faded plastic, bulky/takes up entire frame under seat, has missing pieces like the filter cover ($70 bit o plastic), the screen holding filter is rusted thru from rodent nest & both the rubber inlet snorkel & also many baffle ridges inside the airbox have been gnawed & chewed completely away, so mice have already likely negated some, if not all, that fancy rocket science "tuned airbox resonance". The rusty 1/2 missing screen was already a risk of engine ingesting debris (just like a carelessly placed restricter washer could.... i will find pics, the restrictor "washers" used are large enough to be impossible to ingest by the carb)
My goal is to spend under $20 on a pod to both make the bike look much better & also not spend nearly 10x as much for a stock air box. Or on some bikes pods are even used just as a matter of convenient service. So lets just pretend an airbox is unobtainable....its post apocalypse, run whatcha brung type deal, whats the next best thing a guy can come up with???
The only alternatives I find are a venturi or pod filter so looking for ways to make a pod work while limiting some of their negative drawbacks. A shroud that protects from turbulence & keeps overall airflow at stock while also keeping some vacuum in the inlet could potentially mitigate 3 major pod drawbacks using just a beercan shroud !! Lets imagine this beercan is big as the stock airbox, & with a hole trimmed out that equals the stock inlet, it is in effect an AIRBOX at that point ! Leaving just quality of filtration & intake resonance as the pod downsides to deal with (i hope)
I know it seems absolutely redundant to "restrict" a pod filter...& If you put it on for "power" IT IS !
However the methods I mentioned all seem to be in pursuit of getting a pod filter to flow air in a similar fashion to a stock box (i.e. NO PERFORMANCE GAIN). Now if a pod filter flows MORE air than stock ( Even tho some here have said they flow LESS), the only way to get a closer to stock airflow is to restrict it somehow.
Yes, this means reducing the overall potential power a pod is capable of flowing, but only back to a level that equals the stock airbox. In effect a restricter plate/washer/butterfly or shroud could remove the need to re-jet the carb & some associated fueling headaches because airflow would not be increased over stock. It may also help retain inlet vacuum for proper CV operation, & if done in the external shroud fashion, could help with airflow turbulence.
Sure sounds to me like 3 ways to address at least a handful of the pod filter issues. The "tuneability" aspect of being able to trim the restriction either by changing washer, trimming shroud or turning a butterfly was what caught my mind...i have heard of guys drilling holes in airbox or removing filter or using a more or less restrictive filter medium in order to dial in jet sizes & airflow or diagnose rich/lean conditions. T qhe methods I mentioned would all do a similar thing, with the added benefit of being almost infinitely adjustable.
Sounds like most if not all here are pretty set in their ways of pod filter = bad and perhaps its correct. But i am looking for a way to have the NEXT BEST THING TO AN AIRBOX, sure maybe not as good, but close as i can get while still looking good & costing little... Who knows, maybe one can dial in proper dirt filtration, inlet vacuum, turbulence & actual overall airflow on a pod to the point the only thing an airbox does better is "resonance tuning" ( which indeed could be a powerband change) but i get the feeling even if someone CAN dial in a pod filters airflow to be 95% as good as stock, nobody would ever believe it anyways so the myth may just persist forever
Maybe think of it this way ? a trombone has an "adjustable slide" to change the length of the "horn" & can therefore play a full range of frequencies. An adjustable air intake of some kind (whether its variable height venturis , holes cut in an airbox or even a washer plate in the filter inlet) should be able to be TUNED ! & while it still may not be possible to make it play the identical "note" to stock, i would think having the ability to vary, change or adjust the airflow would give a guy a much better chance of playing a "similar tune" vs. the one-note-wonder that a universal pod filter stuck on a random bike would play.

 

This is a pod "hack" to cut airflow down to stock level, look closely you see plastic tube inside filter...both blocking much of the filter area to decrease airflow & also extending the airflow path outwards from the carb inlet. In a way the tube is a "velocity stack" (with TERRIBLE airflow turbulence around the inlet compared to a true venturi shape ! ) the tube & filter surface restriction supposedly also allows some proper vacuum in the inlet...
I think the plastic has potential to deform & be ingested by engine, but plastic intakes are common i suppose. A more permanent design can be done once dialed in.
I dont have pics of the "beer can shroud method" but the idea is a closely placed shroud on the outside achieving similar results to an inside the filter tube/ velocity stack. The gap of the shroud to the filter along with the overall size can be adjusted until the bike runs close to stock then a permanent setup made in non beer can material
In addition to the filter blocking methods, there are large washers (equal to the inlet of carb or bigger), with various I.D. to achieve a restriction inside the intake but without blocking the filter area itself.
i dont have pics of beer can shroud, but think of it as a wind & water splash protector, anywhere from a small patch blocking off a small bit of the filter, up to a huge canister fully enclosing the pod, with any range of inlet hole size, tailored to the specific bike by slowly enlarging or reducing the shroud or inlet area till the bike runs best.

 

I have not looked into alternate carbs, presumably a VM mikuni can be had relatively cheap ? ( are we talking china knock-off or oem ?) Have had decent luck with china carb on 2 bikes but do prefer japan built carb if possible. But perhaps a $40 china carb (that works like a mikuni vm) could be the answer too.
That could be a path to take to avoid CV pod issues, tho i would think it could take a bit of effort to get a good match for jets, intake boot & cables ? Call me a simpleton, but the idea of being able to steadily tear off a bit more beer can cover, or turn a butterfly valve till it runs right sounds SO much easier ( i have no idea if its even possible, But if so, it sure SOUNDS easier LOL)
I am surprised the idea of being able to fine tune an intake isn't more alluring, sounds like a novel approach to the pod problem, in a way like a supertrapp muffler where the exhaust can be fine tuned with stacking washers, or a variable intake on an F1 car, or electric exhaust cutouts, just another way to fine tune airflow of a machine. I think using terms like "washer" "restrict" & "beer can fix" might put people off but those things can often all contribute to creating amazing things ( & some terrible ones too)
a bit of a "hybrid" pod/enclosed shroud setup utilizing a shroud to counter turbulence, an inlet restriction to simulate the airbox snorkels flow capacity & also some inlet vacuum build up Could be good or bad. Changing the airflow vacuum & turbulence is what the stock box did, maybe there are other methods to change those things like instead of a plastic box use a beer can shroud, inst3ad of a rubber inlet snorkel use a restricting washer or butterfly, to gain the vacuum capacity behind the filter that a large airbox has, possibly use a vacuum reserve canister off a hose ?
...I may just have to do it instead of asking questions & learn the hard way
So whats the deal with mikuni vm ? Can they be gotten somewhat frugally ? how hard is it to get one jetted to run well ? Im guessing they must be more resistant to lack of intake vacuum ? But would think turbulence, "excess" airflow & (maybe) lack of intake tuning resonance could still mess with ANY carb with a pod filter ? Or is it only CV carbs with those issues ? Do pods causing turbulence or loss of intake vacuum & resonance tuning affect a VM Carb ?

 

I guess i missed the "multiple low cost alternative options" .....Buy a $200+ oem box (misses the objectives looks & budget), or buy a whole new carb in addition to jets & filter or velocity stacks then maybe start back from square one getting air/fuel ratios right ($$$$)

It amazes me there is such unwavering faith in the perfection engineered into the design of an airbox of a 40 yr old bike (& not a hi power design). A intake that had to be a fender, battery box, fuse panel, seat bottom, that fully fills in the frame to achieve a look that matches the body plastic AND be a filter space tuned perfectly...all those things sound like compromises a yamaha intake tuning engineer had to make tradeoffs for in pursuit of intake performance. Without all the other design constraints I imagine the intake would not be identical in design !
Changing airflow is a tuning issue. Being able to tune intake airflow to correct issues like turbulence or vacuum seems like a good way to get ideal performance, (or in this case, just to run a different filter setup) An engineer without limitations like fitting a seat battery frame & fender into the design may well be able to make a functional intake with some effort & creativity, maybe even using stuff like beer cans in the prototype stage
but maybe it will be a cold day in hell before its agreed on here which is sad to think there is an element of disbelief in new or different ways being productive or effective. Tried & true is all that will do ? if that is the mindset I will quit asking silly questions here & go get my hands dirty doing it, its for fun, not to make anyone upset over different ways, I just believe theres more than one way to solve most problems & sometimes it can be fun to try them out !
Again I think some have been put off by terms like "beer can" fix. Is there a legitimate way or term to tune intake airflow ? Be it variable venturi, drilled airbox, velocity stacks, different filter medium, trimming of snorkel, etc. Sure maybe some of the methods suggested use less than permanent materials, but only during dial-in testing !
It really didn't feel like heresy to suggest attempting to fine tune an intake setup using any of a number of methods described to change airflow.
I thank those who have offered ideas & carb suggestions & will look into them

 

initially I figured I have an early non-CV carb, & a pod would be "ok", but suggestions here said no, so I resolved to find a way next spring.
Had put the project off for now, (not looking to kick a dead horse here on the forum LOL)..but then youtube offered up the pod videos suggesting at least some tuneability, with much more than just one viewer commenting they had finally achieved some success using pods ! (thanks to some of the "hack" methods) which got me back here asking if its plausible to fine tune airflow. It sounds like nobody here has had success trying in anywhere from hundreds, to thousands of yrs of experience & or are unwilling to believe in other possibilities or progress vs a 1980s engineer, I get it. I have utmost faith in Japanese engineering, & yamaha in particular. Who knows, in Japan maybe they pulled an airflow engineer off the race team for this literal farm bike design & no other human can ever surpass that feat, here we would put that low end farm work on an intern & say good enough
Mankind has shocked himself time & again achieving the "impossible", sometimes even with little or no skill involved (AKA dumb luck) greeks like Archimedes, ancient china, math & astrology in the middle east, all achieving feats of science millenia ahead of the curve. Some were genius, some pure chance. Now your average tinkerer with a garage is better equipped with information tools & resources to hack, create & invent, than even the most well funded alchemist or scientist even dreamed to access to in times past.
We now sit at 8 billion possible genius' (or idiots !) so to me saying it cannot be done to anything ? I see amazing things daily i once thought nigh impossible & wouldn't believe if I didn't see it with my own eyes
I seriously appreciate the input guys !! Call me the devils advocate seeking answers if you will. Some rise to the challenge & put forth great info. The amazingly comprehensive collection of knowledge, engineering, math, & science contained just in links provided in this 2 page thread alone are enough to learn & develop at least a basic understanding of the seeming voodoo that goes into airbox design, (& why pod filters are best for starting a discussion)