Topic: Pod redesign or enhancement thoughts

[Dusthawk]

I was sitting here thinking long and hard about the pods I am planning on installing on Rita and it occurred to me that the reason pods are a problem is because the vacuum is reduced due to a much freer airflow through them. Then, it then entered my mind that what if a formed block of dense open cell foam were inserted inside the pod? Would it restrict enough airflow to create enough of a vacuum to offset at least a portion if the loss?

If this worked it would go a long way to correct the vacuum loss and rejetting the carbs would be nullified.

Is this just a whimsical idea or a valid idea worth looking into?

[Kong]

The problem with pods doesn't come from lack of vacuum, it comes from the chaotic airflow at and into the carb intake.  Simply put, there isn't enough room inside of the Pod for the airflow to straighten itself out before entering the carb.  The problem is self-solving as engine speed goes up (and the boundary between chaotically turbulent air and clean flowing moves toward the inlet) but at low and mid-range RPM that chaotic airflow will result in stumbling and what will seem like a barrier RPM below with it won't run worth a turd, but above which it will run just fine.  All the jetting and needle changes in the world won't fix it.

[Mekagojira]

I vary my leg position to make her ride faster.  And I do the same thing on my bike.

[Blitzburgh207]

Do pods really make it run like sh!t?

[DarcyCB400F]

http://forums.sohc4.net/index.php?topic=86630.0

worth a read...

[Blitzburgh207]

Son of a ... I just bought four new pods yesterday.  They cant be too bad if so many guys are running them right? haha. And wouldnt that decrease horsepower and efficiency as well if its running hotter? Purely aesthetic? What a bummer.

[Roach]

Son of a ... I just bought four new pods yesterday.  They cant be too bad if so many guys are running them right? haha. And wouldnt that decrease horsepower and efficiency as well if its running hotter? Purely aesthetic? What a bummer.

they run like poop i find if you get a cross wind or anything you bog down..some people have had luck but it takes allot of carb tuning re-jetting more tuning more re-jetting they arn't something you can just put on and ride

[Blitzburgh207]

My bike's in the shop right now getting a tune.  I figured I ought to get the first one done professionally so I KNOW it's right haha. That's why I'm having them put the pods on cus I was worried about tuning it.
So you're saying they constantly need tuning?  Is it like an every week/month thing, or once you've got it locked into the proper settings it tends to run smoothly?

Thanks

[Roach]

My bike's in the shop right now getting a tune.  I figured I ought to get the first one done professionally so I KNOW it's right haha. That's why I'm having them put the pods on cus I was worried about tuning it.
So you're saying they constantly need tuning?  Is it like an every week/month thing, or once you've got it locked into the proper settings it tends to run smoothly?

Thanks

sad to say your shop might just put the pods on and say have a nice ride...running smooth with pods is kind of an oxymoron you might hink its running great but really it isn't

i think it might be time for you to grab a manual and start reading and reading and reading... as people have said above the air flow needs to go into the carbs in away that velocity stacks or stock airbox or tin tops anti pod system can do

[DarcyCB400F]

Just curious Blitz???
Why are you so determined or excited to have pods? Is it the look or perhaps the sound? I am unclear why you or anyone else would want them? What's the perceived benefit?

[Roach]

Just curious Blitz???
Why are you so determined or excited to have pods? Is it the look or perhaps the sound? I am unclear why you or anyone else would want them? What's the perceived benefit?

the looks and the lack there of benefits

[Blitzburgh207]

Well I hope he doesn't take advantage of me  He seems like a pretty good guy.  He used to race way back but he builds custom crankshafts these days. Came reccommended by my step-dad.

Yes, looks and sound  I really like the look of bikes that are as "open" as possible.  That said, I can't see through the bike when I'm sitting on top of it! - so I would rather it run smoothly.
I actually like velocity stacks better, I just found some cheap cones on dimecitycycles and picked em up.  Can you fit filters inside velocity stacks? Or do I chance sucking in anything that gets past the fender?

p.s. I've been reading up as much as I can - my girlfriend is seriously jealous... "oh my god you and your forums"

[Kong]

They look a lot sexier than a stock airbox and if you have a cafe build and desire an open area clean up of the V section of the frame they are just the thing visually.  The stock airbox is about as sexy as a plastic picnic basket and if its been setting out in the sun for twenty or thirty years and dulled to a putrid splotchy gray just about anything would look better - hence the immediate appeal of Pods.  But then if you take the time to search and read you pretty quickly start finding horror stories from guys who are particular about their tuning.  And then you read further and you find that the more a guy knows about tuning the less likely it is he can get pods right, the more particular he is the less he will be pleased with them.  Here's what they are reported to do; if you try to accelerate from about four- or five-grand the engine will snort and stumble and just sort of sit there and do not much of anything until it gradually hits about six grand and then all of a sudden it will once again run like a scald-ass-ape.  And no amount of fiddling with screws or needle height or slow jets or main jets seems to work in fixing it.

[wrenchmuch]

http://forums.sohc4.net/index.php?topic=5410.0;all
Scroll down to just after the section on soda blasting carbs . Titled "What is wrong with the stock Honda induction system?" by
TwoTired. Lots of good info .

[DarcyCB400F]

They look a lot sexier than a stock airbox and if you have a cafe build and desire an open area clean up of the V section of the frame they are just the thing visually.  The stock airbox is about as sexy as a plastic picnic basket and if its been setting out in the sun for twenty or thirty years and dulled to a putrid splotchy gray just about anything would look better - hence the immediate appeal of Pods.  But then if you take the time to search and read you pretty quickly start finding horror stories from guys who are particular about their tuning.  And then you read further and you find that the more a guy knows about tuning the less likely it is he can get pods right, the more particular he is the less he will be pleased with them.  Here's what they are reported to do; if you try to accelerate from about four- or five-grand the engine will snort and stumble and just sort of sit there and do not much of anything until it gradually hits about six grand and then all of a sudden it will once again run like a scald-ass-ape.  And no amount of fiddling with screws or needle height or slow jets or main jets seems to work in fixing it.

So it is a classic case of "fashion over function"... I like fashion as much as the next guy but I hesitate to jeoprodize function to a point where function doesn't exsist. I can see the sex appeal of the pods but I like much more the ability to run the throttle from 4,000 to 10,000 and hear nothing but a constant gratifiying rise in speed and wind in my ears!

[Blitzburgh207]

You think this would be a wiser buy?http://www.steeldragonperformance.com/air_boxes_7.html

[TwoTired]

I was sitting here thinking long and hard about the pods I am planning on installing on Rita and it occurred to me that the reason pods are a problem is because the vacuum is reduced due to a much freer airflow through them.

Yes and no.  There is more than one reason why the vacuum is lost.  See:
http://forums.sohc4.net/index.php?topic=83904.msg945765#msg945765

The simple act of shortening the induction path is one reason for vacuum loss.
The change in filter media type and total area, is another.

Then, it then entered my mind that what if a formed block of dense open cell foam were inserted inside the pod? Would it restrict enough airflow to create enough of a vacuum to offset at least a portion if the loss?

Yes, it could.  But, the vacuum increase would be interactive of the volume of air passing through it.  IF you adjusted the vacuum increase, to match the stock vacuum at air volume and speeds for Idle RPM, the added restriction or membrane turbulence causing the vacuum increase would not be the same as the volume and air speed achieved at red line RPM.  The effects are not in a linear relationship over the range of air speeds and volume required by the engine.

In addition, any filter membrane or open cell foam in an air path will create turbulence in the outflow.  Turbulence severity will increase as air speed increases.  Turbulence changes the path of air molecules from a straight path to a rotational path.  A flag waves in the breeze because of the alternating rotators travel down the length of the flag.  The turbulence was initially caused by the flag pole. disturbing/deflecting the air flow. The flag shows the turbulent effects as a change in pressure the move the flag back an forth.

What you want to avoid is the turbulent rotators to be present and the fuel jet exits.  The alternating pressures change the flow rate of fuel from the jets, making it unpredictable with changing air speeds and different throttle positions.

Simple eh?   

[MRieck]

Do pods really make it run like sh!t?

No....if you know what you are doing and buy the right pieces. An aside...I absolutely hate the word "pods". Seeds and peas are carried in pods.

[mrbreeze]

Do pods really make it run like sh!t?

No....if you know what you are doing and buy the right pieces. An aside...I absolutely hate the word "pods". Seeds and peas are carried in pods.

+1.....fer sure!!!!.....when I crank my throttle.....she goes just fine!!!!

[Dusthawk]

TwoTired, thank you very much(seriously, no sarcasm at all intended or implied) for the description, it really helped to clarify why they are undesirable. Now, that begs the next question, Rita being the awesome chopper she has always wanted to be, what would be the best combination of looks and function I could run that wouldn't clash with the style I am striving for? A stock airbox is out of the question due to the cosmetic consideration as well as practicality, it won't fit where it would normally sit due to the oil tank. I worry about debris intake by using velocity stacks and finding a chrome breadbox airbox is virtually impossible for a reasonable price, last one I saw on Ebay sold for almost $300 and the chrome wasn't in top shape.

On another tack, what about an internal(to the pod) sleeve with vanes to help reduce the turbulence and straighten out the airflow and guide it into the throat of the carb?

I get that a lot of people here completely decry the use of pods and consider them a mortal SOHC sin, but stock isn't what I am going for, not can I implement it anyway. With that in mind, feel free to continue thinking less of me for not going the stock airbox route, lolol.

[Roach]

i was looking at my emigo air pods and was thinking that if you do want the non box look then you might be able to use the velocity stacks out of the stock box and take off the rubber on the emigos. slide the stock stacks inside the emigo filter if that makes sense. i dont have extra stacks to try it now that i am back to my airbox and it would take alot to get them back off...but it is something to think and try and get something home made you will need to rejet but it might not be that bad

[jumpnkill]

Do pods really make it run like sh!t?

No....if you know what you are doing and buy the right pieces. An aside...I absolutely hate the word "pods". Seeds and peas are carried in pods.

+1.....fer sure!!!!.....when I crank my throttle.....she goes just fine!!!!

What jets are you fellas with pods using? 

[Dusthawk]

i was looking at my emigo air pods and was thinking that if you do want the non box look then you might be able to use the velocity stacks out of the stock box and take off the rubber on the emigos. slide the stock stacks inside the emigo filter if that makes sense. i dont have extra stacks to try it now that i am back to my airbox and it would take alot to get them back off...but it is something to think and try and get something home made you will need to rejet but it might not be that bad

Now that would be a good idea, wonder if it would actually fit inside a pod though. I don't have the stock rubber stacks but I am sure I can find some somewhere.

[Kong]

Roach,

Sometime last year I was reading an article (I believe it was published in NASA's "Tech Briefs") about directing airflow in a manner similar to the vanes you suggested.  The Researcher used bundled tubes in the stream rather than vanes and for the life of me I can not remember what the application was, though it may have had something to do with either increasing the range and flow of fire hoses or increasing the effectiveness of a vacuum cleaner.  The results, as I recall, were very much improved rates and volume of flow.   I had mentioned the article to TinTop over the winter when he was doing some of the preliminary work on his filtration system (Dusthawk, TinTop's system is the likely answer to your problem), the one that is currently being called the "anti pods", and told him I might try to incorporate it with his system after it arrives.  I believe he plans to start shipping the first of the systems in the next two or three weeks.

Here, take a look at these two links:

http://forums.sohc4.net/index.php?topic=79491.0

http://www.steeldragonperformance.com/air_boxes_7.html

[Tintop]

i was looking at my emigo air pods and was thinking that if you do want the non box look then you might be able to use the velocity stacks out of the stock box and take off the rubber on the emigos. slide the stock stacks inside the emigo filter if that makes sense. i dont have extra stacks to try it now that i am back to my airbox and it would take alot to get them back off...but it is something to think and try and get something home made you will need to rejet but it might not be that bad

Now that would be a good idea, wonder if it would actually fit inside a pod though. I don't have the stock rubber stacks but I am sure I can find some somewhere.

Been there, done that on a racing kart.  Mounted a K&N 400 filter on a piece of thin wall pipe which was swedged into a filter mount for a larger filter.  Worked well at WOT.   As has been stated a number of times (in numerous threads), it is the stock velocity stacks that are the major influence on low speed, and part throttle drivability.  My stock 550 engine with my filter &  stacks, and open 4 into 4 pipes idles at 850rpm.  There is no hesitation, stumble when you twist the throttle.

I would agree with TT's observation regarding placing foam, gauze, mesh on the end of a stack.  It causes turbulance, and generally offers poor 'real world' vs racing filtering.  As for the 'bread box' filter style, these work but at a cost.  On a 750 you lose the 50mm stacks for +-15mm stubs.    If your looking for a cheap solution, keep the stock stacks and plenum, and attach a K&N to the back.  There are a couple of threads detailing this solution.  Or you can check out the filter thread in my signature for another alternative to pods.

edit: thanks Kong