Pods and there effectiveness

[bluebanshee98]

It's a 2006. It's had ONE rebuild EVER. It's an 8 year old motor. Have you seen the riding I've put that thing through? Fuck an outerwear.

No I only saw some of your hillclimbing videos with the banshee. Hmm I might just take my outerwears off then. Not doubting your knowledge just asking since you have experience in the real world

[shanYE west]

pre-filters are good for .005 microns and larger.  Dust particles start at .0008 microns

[Nieskes]

Maybe you should hire a few more builders and have them conference call and tell you MORE Stuff.

FFS You and your brother climb all over a bike and can't figure out the filters just dirty?

How many miles do you push a bike that dies before you take a peek under the gas cap? LMFAO

Im sorry but this shit is funny.

[locogato11283]

Im sorry but this shit is funny.

 

I thought so too. I was hoping he would go all windy on my post. He never lets me down.

[tfaith08]

I've never seen any effective application for an outerwear, but I clean my filter after every tank so I doubt I would.

 

With longer filters, I just did some crunching on some COMSOL CFD and I'm in agreement that the benefit would come from the straighter air entering the carbs with longer filters as well as the reduction in pumping losses and vacuum associated with pulling from a smaller source. 

 

32mm carb, 3.5 in filter.

 

 

32mm carb, 6" filter.

 

 

From what these suggest, an improvement on the venturi style setup of the carb would benefit these greatly, as would mounting the filter far enough back to allow the carb entrance to protrude into the filter.

 

As you can see, there isn't much net flow difference (color of the flow at the top, which is the engine side of the carbs).  There also is a bit of a difference in jetting due to the flow profile at where the main jet would be.  The 6" filter will be more turbulent whereas the 3.5" filter will be more laminar, which I completely did not expect.  However, a 6" filter will reduce pumping losses around 1.17% over that of a 3.5" filter as evidence by the numbers that I failed to capture.

 

Conclusion, larger filters equate to fractionally more power whereas smaller filters make tuning easier.  BUT, that's based off of suggestions by computational fluid dynamics.  I'd believe what it says because the software was designed by a group of people who know so much about what they're doing that they were able to produce software that is among the most generally comprehensive in the world.

 

For those of you who know this stuff, know that this was done with laminar flow only.  I don't have the motivation to crunch numbers and basically recreate a DM setup that functions over any range, much less a specific one.  Furthermore, I am even less inclined to put that much effort into it since this post will likely be overlooked. 

Edited July 1, 2014 by tfaith08

[sheerider11]

Wait, your builder is bald and missing teeth?

 

I don't call him for stupid shit like this. I've got my setup down to a science. It's proven on the dyno and proven in real world testing.

 

The problem here is that people like windy, who have basically ZERO credentials try to discredit those (me) who have LOTS of experience.

I like windy. He's helped me out and has offered me quality advise. I have no say in what's you 2 do.

Now cam did the bottom end for my girls bike. But 99% of my advise is from him, Jeff at fast or sleeper06.

Well I'm not changing my pods anytime soon but I'm just curious at what point they become ineffective

 

 

 

Sent from my iPhone using Tapatalk

[Bennett131]

I've never seen any effective application for an outerwear, but I clean my filter after every tank so I doubt I would.

 

With longer filters, I just did some crunching on some COMSOL CFD and I'm in agreement that the benefit would come from the straighter air entering the carbs with longer filters as well as the reduction in pumping losses and vacuum associated with pulling from a smaller source.

 

32mm carb, 3.5 in filter.

 

 

32mm carb, 6" filter.

 

 

From what these suggest, an improvement on the venturi style setup of the carb would benefit these greatly, as would mounting the filter far enough back to allow the carb entrance to protrude into the filter.

 

As you can see, there isn't much net flow difference (color of the flow at the top, which is the engine side of the carbs). There also is a bit of a difference in jetting due to the flow profile at where the main jet would be. The 6" filter will be more turbulent whereas the 3.5" filter will be more laminar, which I completely did not expect. However, a 6" filter will reduce pumping losses around 1.17% over that of a 3.5" filter as evidence by the numbers that I failed to capture.

 

Conclusion, larger filters equate to fractionally more power whereas smaller filters make tuning easier. BUT, that's based off of suggestions by computational fluid dynamics. I'd believe what it says because the software was designed by a group of people who know so much about what they're doing that they were able to produce software that is among the most generally comprehensive in the world.

 

For those of you who know this stuff, know that this was done with laminar flow only. I don't have the motivation to crunch numbers and basically recreate a DM setup that functions over any range, much less a specific one. Furthermore, I am even less inclined to put that much effort into it since this post will likely be overlooked.

[WINDYCITYJOHN400]

I've never seen any effective application for an outerwear, but I clean my filter after every tank so I doubt I would.

 

With longer filters, I just did some crunching on some COMSOL CFD and I'm in agreement that the benefit would come from the straighter air entering the carbs with longer filters as well as the reduction in pumping losses and vacuum associated with pulling from a smaller source.

 

32mm carb, 3.5 in filter.

 

 

32mm carb, 6" filter.

 

 

From what these suggest, an improvement on the venturi style setup of the carb would benefit these greatly, as would mounting the filter far enough back to allow the carb entrance to protrude into the filter.

 

As you can see, there isn't much net flow difference (color of the flow at the top, which is the engine side of the carbs). There also is a bit of a difference in jetting due to the flow profile at where the main jet would be. The 6" filter will be more turbulent whereas the 3.5" filter will be more laminar, which I completely did not expect. However, a 6" filter will reduce pumping losses around 1.17% over that of a 3.5" filter as evidence by the numbers that I failed to capture.

 

Conclusion, larger filters equate to fractionally more power whereas smaller filters make tuning easier. BUT, that's based off of suggestions by computational fluid dynamics. I'd believe what it says because the software was designed by a group of people who know so much about what they're doing that they were able to produce software that is among the most generally comprehensive in the world.

 

For those of you who know this stuff, know that this was done with laminar flow only. I don't have the motivation to crunch numbers and basically recreate a DM setup that functions over any range, much less a specific one. Furthermore, I am even less inclined to put that much effort into it since this post will likely be overlooked.

No this post won't get overlooked.

This is the most SOLID tech info posted on this site in a LONG TIME.

Now the info and filter discussion is in full swing and we can all start to see where the results come from.

See, the initial info would support that a 6" pod filter should be fine. But more input shows how filter length and shape can effect the air flow and boost power.

 

This is supported by the dyno testing that showed bigger numbers from bigger filters.

 

Or you can listen to Tyler who can't understand anything technical and doesn't know how or why ANYTHING works.

 

I like UNDERSTANDING what I'm talking about.

But discussion about topics he cares nothing for irritate him and he needs to derail others who are trying to work together in having an open conversation on a topic.

(If Tyler comments on page one with his perspective and the topic makes it to a page two......then he's butt hurt you all didn't fall into line and worship his statement.)

 

Here is another thought.......would it be OK if members shared info and new/younger/inexperienced members we able to read along and learn?

Or should EVERYONE just sell their shit, call Tyler for a list of approved parts and motor builds he finds interesting, have Cam build every motor and then go race up a hill?

No real need for a website.....Tyler could just post his life on Facebook or maybe Blog and you could all follow him.

 

Was that Windy enough?

[bluebanshee98]

No this post won't get overlooked.

This is the most SOLID tech info posted on this site in a LONG TIME.

Now the info and filter discussion is in full swing and we can all start to see where the results come from.

See, the initial info would support that a 6" pod filter should be fine. But more input shows how filter length and shape can effect the air flow and boost power.

 

This is supported by the dyno testing that showed bigger numbers from bigger filters.

 

Or you can listen to Tyler who can't understand anything technical and doesn't know how or why ANYTHING works.

 

I like UNDERSTANDING what I'm talking about.

But discussion about topics he cares nothing for irritate him and he needs to derail others who are trying to work together in having an open conversation on a topic.

(If Tyler comments on page one with his perspective and the topic makes it to a page two......then he's butt hurt you all didn't fall into line and worship his statement.)

 

Here is another thought.......would it be OK if members shared info and new/younger/inexperienced members we able to read along and learn?

Or should EVERYONE just sell their shit, call Tyler for a list of approved parts and motor builds he finds interesting, have Cam build every motor and then go race up a hill?

No real need for a website.....Tyler could just post his life on Facebook or maybe Blog and you could all follow him.

 

Was that Windy enough?

Mehh I felt stronger winds before lol

 

 

Sent from my iPhone using Tapatalk

[shanYE west]

keep in mind this is a 3.5" filter vs 6" ( Conclusion, larger filters equate to fractionally more power whereas smaller filters make tuning easier)  I'm still under the impression that 10" and 12" filters will have a minimal gain if any vs 6" filter. (no pre filters)  Once the filter reaches a certain length, the flow pattern shouldn't change. What that length is.. I dont know, but going by the data provided it dont look like it will change much past 6"

 

I think in your case you saw the increase because your using pre-filters and they obviously hinder flow rates and larger area filters are required.   12" with pre filters vs 6" no pre filter would be a good test.

 

I wish they made a 6" universal velocity type filter.

[WINDYCITYJOHN400]

See now this is the kibd of conversation I try to have. Shanye you make a good point.

 

I did a test with NO filters. Installing the 6"pods HELPED the power.

I've tried with and without Outerwear's and on my 370 long rod motor, the results are the same.

But with the 10mill Cub, the motor liked the longer filters with or without Outerwear's.

I do agree that the longer filter allows use of Outerwear's that have enough surface area to no longer be a restriction so I'm able to run them for more filtering protection. (As an HVAC tech I spend my life dealing with damage from poor filters. So it's a priority to me.)

 

I think once you get into the REALLY big motors or drag bikes that see very low hours, then Outerwear's are optional.

But for the record.... my 10mill made 2 more HP with the bigger filters vs my 6"pods even with NO outerwear's.

Edited July 1, 2014 by WINDYCITYJOHN400

[dave5.0]

Your welcome for this post Windy.

 

So we are talking about losing power from pumping loss. So it takes power to pull the air through the filters that the engine needs. So that would make sense to me that the larger filter area then would be better. Whatever motor can only pump so much air. So the air inside the filter is free or already worked for. So that gets used up more has to be pulled through the filter to replace it. There's a certain amount of restriction in the material. So the more filter material it has to pull through the less it has to work? Am I getting that right? Or making any sense? So it should be easier to pull 10 cfm of air through 20 sq in of filter material than it is through 2 sq in. Right?

[locogato11283]

Excellent posts.

 

Just so we're clear...

 

Big filters FTW.

 

Outerwears are unnecessary.

[87sheerips]

Do not tune/only ride = small filters = me = michigan = win.

[tfaith08]

When resonance is a factor, like any situation with a 2-stroke, you have to account for it.  If you're a buy and try kind of guy, you can skip this thread entirely.  For those of us who aren't financially comfortable enough to buy 20 sets of filters to try and see what makes the most power or can ask someone else to do it for us, calculating a filter size requirement is best. 

 

The negative pressure wave from the crankcase that reaches the filter is what pulls air.  When that wave hits something or is reversed by turbulent flow, anything beyond that point is useless.  Frankly, by the time you calculate to this point, you can select something within 1-2" of what will work best. 

 

Say that I generalize an engine that fits sprinkleman's description of 130hp and pulls 325CFM.  Of course, this is extremely generalized unless we have the same pipe, porting, rotating assembly, piston profile, reed geometry, carb boot dimensions, carb, and filter.  In that case, I could put together a CFD video that would show you how to calculate it, but I don't have anyone paying me to put weeks into creating a functioning Banshee engine and to wait for weeks for the module to process, so I guess generalizing this, unlike like uneducated generalizing anything else to do with any engine ever, has a benefit.

 

Of that 325CFM, we can say that 162.5CFM goes to each cylinder and through a 38mm carb.   Until the time that vacuum wave reaches the filter, it has experienced only a small portion of turbulent flow.  However, once the vacuum wave reaches a large source of air (filter), the flow becomes almost entirely turbulent.  Roughly how and exactly when this happens is largely dependent on the properties of the vacuum wave and the filter dimensions and flow potential. 

 

When the wave reaches the filter, air flows toward it from all directions.  When that air flows, more air follows it as a result.  When the air that is closest to the filter begins to flow toward the vacuum, it naturally pulls from the air that can move with the least requirement of force, which is air inside the filter.  When the air has flowed enough to create a pressure differential that is great enough to make air flow through the filter, we see another pressure wave, only positive.  This air has overcome the vacuum by sheer momentum and creates turbulence as a result. 

 

Generally, this will all happen very quickly and flow will occur in a way that would represent a sphere.  This stops when the size of the sphere of flow reaches the filter and begins to pull from air closer to the back of the filter.  The air will then begin to flow from outside the filter and fill behind the vacuum wave, creating a nearly symmetrical pattern of turbulent flow in axis around the center line of the filter.  The turbulence then pulls air from each direction.  Resonance takes effect when these waves are timed and dimensions are altered to compensate.  Therefore, filter diameter plays a crucial role in power production.  This isn't as great as total filter area, but it is extremely important. 

 

The factors that affect this are the velocity of the air, total flow, and filter dimensions. 

 

In my eyes, a longer filter creates a constant net direction of flow, whereas the diameter alters the initial inflow.  One will absolutely affect the other, so why doesn't someone or their builder chime in on filter diameter for a minute?

Edited July 2, 2014 by tfaith08