air intakes

i was just wondering if anybody has made a pod filter intake/manifold that pokes out the side and forward like some harleys have?

 

I just took rhe pods off my bike after not being able to properly tune it. But I have seen it never asked anyone how it rode like that though.

 

I just took rhe pods off my bike after not being able to properly tune it. But I have seen it never asked anyone how it rode like that though.

 

what i was thinking was have the 2 left merge into one going out and the same for the 2 right. not sure if this is possible? so i would only have 2 pods. thoughts guys?

 

does anybody have any idea on what size of filter/pipe i would need? Doubling the area of a single intake for each side seems pretty large but is that what is nessesary? I was thinking of mocking one up in pvc then getting a fab shop to make them up nice and pretty.

 

Before you start heading down the Yellow Brick Road and think about modifying the Plants Intake; research and learn about what you are getting yourself into.

Many have been down the road before you.
There are some Fine Tuning issues that are difficult to attain resulting in experimenting with Kits and New Jets.

Before you deviate from Stock, ... Fine Tune it Stock with great attention to details finding an exceptionally good state of Tuning.
Arrive hear, ... first.

After you have Mastered the Fine Tuning that WILL provide you with terrific performance and a Base-line to return too if Mods present problems.

Don't get all giddy about how trick you can make it L@@K, ... before you get the experience of finding how well you can make it run.

 

I appreaciate the response. I have already tuned it up with a vac tuner and a colortune. I know what your saying though. I am in a very "pre" stage of this idea, just wanted to put feelers out there and see if anybody had any thoughts or ideas! any other suggestions?

 

Nope, nobody does............we all know better.

Dave

 

Get yourself a Genuine Yamaha Factory Workshop Manual.

For right now, ... best advice I got for you!

 

Come on man! where is the fun and adventure in that!

 

I have played around ith this idea the problem you run into is getting even airflow to all 4 carbs when you break it into 2 with the air coming in from the side the problem you face is one of the two will get more air than the other

 

hmmm did you increase the size of the pipe or did you keep it the same diameter as the intake of the carbs? I would think that as long as you had access to enough air that that would not be a problem? Thanks for the input

 

It's not "fun and adventure" we've tried it. You'll either get something half decent but not what your bike is capable of, Run your engine so lean you blow it up, or say screw this i wanna ride and put the airbox back in....

 

What Hellbilly said.
Remember that Harleys don't use CV Carbs, which is why you can do whatever you want to the filter intake and exhaust.

 

You might be able to work something up with some round slide carbs, but that would need some throttle cable and choke work. Not to mention trying to work up a carb rack.

 

If you have tried it, can you explain to me what you did and why it didnt work so I can get a better understanding of why it won't work? This is the first time I have experienced this much negativity on this site. Responses like "we all know better" and "it won't work" is not very helpful as to helping me understand why it will not work. Nothing is impossible and it seems to be that this should be a fairly simple Mod. Yes it will definatly be some trial and error but it seems that it should be just math to calculate how much room you need for the air. If I am wrong, can somebody please explain as to WHY?

 

So far with what i have been reading the "Vortex" created by the air filter cone does not create enough pressure for the diaphragm to operate correctly.

i am working on a bike that never came with the stock air box, it was supposted to be a parts bike for me... turned out to be a restoration build. now i am thinking combining intakes into 2, like you are saying. and adding a honeycomm in the tube to linearize the flow. so that it will still be smooth straite air, but comming from a pod filter and pointed tword the front.

 

ohhh so when the air goes through a pod, it turns into a "vortex", so my added the honeycomb it "evens/flattens" the air back out allowing pressure to be even and smoother? interesting, I never would have thought of that. would a normal application of pod filters not create the same "vortex" effect or is it because the length of intake is shorter it does not have a chance?

 

Not really a vortex.

There are a couple of variables in play. The big one is the air speed.

http://en.wikipedia.org/wiki/Venturi_effect

The restriction prior to the entry in the carburetor acts to make air move faster. Removing the airbox makes it slower. Slower air stream hitting the jet leading to the diaphragm changes the amount it lifts the piston. Less piston lift means less needle lift means less gas in the mixture, means lean running. Also, the amount of air hitting the carb can be changed by a crosswind with the pod on.

This is why velocity stacks were invented.

 

"Where's the fun and adventure, ... you say!"

Those who have gone before you have intimated that there is no fun and adventure.
The voices of experience should be valuable enough advice to guide you into avoiding an enormous hassle and getting you to get fine-tuned ... stock, ... before you begin trying to accomplish what they have already tried and found unacceptable results in one form or another.

We are all trying to get you to read the sign that says: "Danger. Thin Ice."

 

I get that for sure, its not that I am not willing to listen, I just want to know why. I understand now the reason that there are difficulties in doing this. I am still intrigued and think it would be cool. I definatly rely and have used the experience on this forum and will continue to. I just think constructive critisism is better than "you will fail" and dont worry, ive seen the sign haha. I wont be doing anything drastic without getting quite a few more ducks in a row. Thanks!

 

This site is DEFINITELY geared towards restoration over modification. I would love to see more of these projects, ambitious though they may be. More power to you man! And just because it hasn't been done before, doesn't mean it can't be done.

 

once i get the bike put back together i am going to be working on the intake. trying to get it to operate correctly. i am just going off things i read. im not going to stop working on it because they say it dont work. I want/need to see it for my self and see what i can do to make it work.

the idea for the honeycomb comes from my experience with wind tunnels, the fan creates uneven air streams and some area's get low pressure and other's get high pressure, makes for terrible results. than you add in the honeycomb and the air flows threw in straight lines, perfect for testing. even pressure and volume.

I didn't even think about drop in volume from the first cylinder to the second. i forgot it mostly is negative pressure, where they have to suck air in instead of having air forced in. so ill put in an air accumulator/tank.

 

Hi, I'm by NO means an x-pert on carbs, but if you'll read the thread " SIMPLE MOD MAY SOLVE POD TUNING HARDSHIPS! ", you'll see a lot of the the gremlins involved with pods. Also I think it was Rickomatic or chacal that has a thread about jets that tell you "go up so many sizes for pods so many for straight pipes, etc. A lot of guys get "acceptable" performance with pods, just not factory performance. I think the basic problem is that these carbs are different than the ones on bike where you can run pods. What you're talking about is a form of a log manifold like they used to run on hot rods. You might be able to do it, but you're in for a lot of headaches first. I gave up on pods and put my airbox back in, and I have a hardtail. Hope you do better than me.



Edit: spelling

 

Sorry, quick second thought here. If you're going to put on an "accumulator-tank". Isn't that what the airbox does in the first place? Just a thought.

 

ya pretty much, but this bike never came with an air box, the PO took it out for some reason.

 

A couple of people have made pvc air intakes with some success and trial and error. If you decide to go back to an airbox and can"t find the original, you can make a custom airbox.
If you go with the pods, definitely use velocity stacks between the carbs and filters.

 

The pod discussion has been going on here since around 2006.... the simple reality is that Constant Velocity (CV) carbs dont play nicely with them, because quite plainly the pods dont give the "constant velocity" that the airbox and boots (velocity stacks) provide.

pods are a mod that risks blowing your powerplant due to the extreme lean condition they cause. IMO that's reason enough... Decreased performance, and months of work for marginal results are other popular reasons as well.

Trust me, with the knowledge on this site, I'm surprised that someone hasn't got it solved yet. RickCoMatic probably came closest too... but it just comes down to the fact that CV carbs are not Slide carbs...

http://en.wikipedia.org/wiki/Carburetor

 

HI NEW TO THE FORUM SOUNDS LIKE PODS ARE A HANDFULL OF TROUBLE IS THERE A SET OF CARBS THAT FIT THAT ARE SLIDS RATHER THAN CV OPERATED JUST GOT A XJ750 1986 DONT WANT TO US THE AIRBOX AS I AM CHOPPING ITR DOWN AND WANT THE LOOK AND EASE THAT PODS GIVE

 

Me too! Use the search feature on here. I know it's been done with some heavy modifications... nothing bolt on and go.

New member/new bike. I'm gonna give you the standard warning speach bro....

Check your rear brakes for delamination
check your tire and brake hose date codes. replace if older than 4 years
check your master cylander and calipers too.
check your valve shims
rebuild your carbs

I would suggest doing your valve shims/carbs/tuning BEFORE you mess with your pods. Get her running like a raped ape first.

 

Too bad nobody's come up with a way to make faux pods. Something that "looks" like a pod but has no increased airflow. Somehow measure the air flow on a standard air box and than creating a material and and difuser that keeps the same air flow as standard. I wouldn't dare take my stock airbox off, but I always have dreams of picking up a second XJ and making a cafe racer out of it. The stock air box is hardly and attractive aesthetic

 

Sure would be nice to invent some 1-into-4 single carb intake manifold. I've seen some pretty cool setups, but only for drag racing. As for the air cleaner, there's a guy that used to make a 1-into-3 custom job for triples. He won't answer my calls/emails however.

 

Me and a buddy both bought running project bikes. His a '82 Suzuki 650 and mine an '82 XJ750 Seca. Both of us are too irreverent for a restoration project at this point in our red bull fueled lives. (I'd love to if I had the money after seeing some of the beauties on here and elsewhere online.) We both decided to take off our air boxes in order to install Pods. Luckily we decided to do his first. Lo and Behold, the exact issues that have been mentioned here have been plaguing me and my pal. He discussed the issue with a local Bike mechanic and was told he would have to re-jet via a $24 a go guess and test game featuring 160 jet options. Needless to say last night we put the air box back on his. Mine is still nestled into my frame most likely in the same place a very hard working Japanese factory worker placed it and after reading this, unless some major cojones spring forth, that is where I intend for it to stay. Thank you XJForum!!!

 

If pods are simpler and better than why didnt Yamaha put them in originally? I cant imagine how many accountants and engineers worked to design these bikes.

 

1. What do accountants have to do with it?
2. Where would we all be if nobody tried to improve on something? Engineers design a product to meet a set goal of specs, doesn't mean that the product can't be improved. Guess Yamaha shouldn't have made a turbo or anything over 500cc's and we should all bet putting around on scooters.
CV carbs are a PITA to tune, mods can make it harder but it can be done.
We should be helping someone with making the mod work right and safe.
If we're going to discourage people from making mods then this forum should be removed from the site.

 

bean counters have everything to do with it. See#2 the accountants write the bottom line on those specs. would you want plastic fenders or pods? does the alternator have any extra in it? no it would cost more. 4 air cleaners or 1?.....
CV carbs ain't no harder to tune IF you have unlimited access to a flowbench and a dyno AND a assortment of parts, jets we can get but how about slide springs, slides with different cut-aways, needles with other tapers, different length manifolds. they had all that stuff at the factory, we don't.
modify all you want but the resources just ain't there to change carbs to pods.

 

In all honesty, I'd love to try the Pod mod in the future, but im glad to know that its a winter project at the very least, before getting started and thus being forced to miss out on some beautiful riding weather.

 

We don't discourage "Mods"

We do offer a caveat to those who are thinking "Pods"