2014 / 2017 airbox snorkels

[dave]

Thanks for the education PD and Doc!

[SportsterDoc]

If you are implying this part is strictly for sound deadening, I can assure you there is more to it than that.


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No, this part serves several purposes:

1. It reduces sound. With the top of bowl sliced off on mine, the airflow is louder than my stock exhaust.

2. It serves as a snorkel, in that it (a) draws air from a location less likely to drown the motor in heavy rain and (b) that air may be cooler than closer to the motor (think cold air induction).

3. Properly designed, it should also direct airflow to pass through the air filter evenly. On my 2016 Nissan Frontier (4.0) the air box internal deflector should have done that, but one section of the flat air filter was getting dirtier than most of the pleated area, until I modified the deflector.

To determine if the sound reduction is at a cost of flow efficiency, measure the area of the snorkel intake in comparison to the filter inlet.

A typical V8 in the sixties and seventies had a silencing tube feeding a round filter with the silencing tube inlet smaller than the carb throat. A high flow intake could be easily achieved by simply using a taller air filter, so that air flow came from the entire circumference.

On pre-04 Sportsters, a high flow intake was easily achieved by using a filter backplate which allowed the ham can more space around the air filter. There may also be an increase of CFM with a different air filter. Instead of spending over $100 for a Screamin' Eagle high flow intake (which came with a K&N, pre 04), the same/close to the same results came from drilling the backplate with several 3/4" holes around the outside perimeter of the air filter.

For the CB1100, 171 CFM is required at 8,500 RPM.
1140 cc x 8,500 RPM (redline) = 9,690,000 cubic centimeters
Divide that by 2 for a 4 stroke = 4,845,000 cc = 171 cu ft per minute.

I contacted Hi Flo to ask if they have a CFM rating on their HFA-1932 and if they have a comparison to the stock Honda air filter. I found no CFM rating on the K&N site for their HA-1301.

A K&N HD-900 is rated 203 CFM. A CV40 carb on a pre-04 Sportster will handle 185 CFM. The 1200 cc motor will draw 131 CFM at 6,200. A 1250 will draw 165 CFM at 7,500 (very high revs for a push rod motor).

I suspect that the stock Honda filter does not impede flow. If that is correct, air flow will be maximum if it enters the air filter with minimum interference (negatives include smaller inlet, turns, surface friction).

Intake manifolds (carb to heads) can be designed for different requirements. For example, the old Edlebrock SP2P manifold for small block V8s was designed for torque and fuel efficiency, but not particularly effective over 4,000 RPMs. This is where plenum configuration and runner design has an effect. A "high-rise" intake manifold allows flow with less turn interference.
Received this response from Hi Flo:

All our HFA air filters are designed to be functional duplicates of the stock filter they replace. I do not have the individual specs for each filter as we are not selling them as better than OE but as direct replacements.

So, still no CFM info.
If the CFM rating for stock Honda 17210-MEJ-981 or HFA-192 exceeds the 171 CFM that the 1140 cc can pull at 8,500 RPM, then there would be little, if any advantage to a K&N.

K&N response:

Thank you for contacting K&N. That filter is flowing 498.64 CFM.

Thank you,
K&N Customer Service & Tech Support
tech@knfilters.com
http://www.knfilters.com
Phone: (800) 858-3333

[chync_imp]

Whoa there....

"Put it this way- I could have bought them if I wanted to, but I think they are way too big for the bike's needs even with the cams I am going to install."

What new cams??

This is exciting. How far have you got with this?
I'd love to run smoother cams. I'm sure my messing around (99 Rwhp) has exacerbated the miss-timed valve opening they claim to have built in for character. It may be all in my head but I'd love to know if 'regular' timed cams would feel better.

On another note, I've got TSR Air Intake, Air Funnel and Cat free pipe mods and it pulls clean and strong from naught to limiter. It may be to do with the AutoTune I have fitted tho.

I'm having a day in the garden and removing the airbox today. I'm going to just run it with the Velocity stacks for a couple of days and see how it goes... I'm just curious and I like removing things ;-)))

I've also always disliked the massive black plastic airbox, aesthetically. I'll let you all know how it runs...

What exhaust are you using? Yoshimura?


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[Guth_imp]

Whoa there....

"Put it this way- I could have bought them if I wanted to, but I think they are way too big for the bike's needs even with the cams I am going to install."

What new cams??

This is exciting. How far have you got with this?
I'd love to run smoother cams. I'm sure my messing around (99 Rwhp) has exacerbated the miss-timed valve opening they claim to have built in for character. It may be all in my head but I'd love to know if 'regular' timed cams would feel better.

On another note, I've got TSR Air Intake, Air Funnel and Cat free pipe mods and it pulls clean and strong from naught to limiter. It may be to do with the AutoTune I have fitted tho.

I'm having a day in the garden and removing the airbox today. I'm going to just run it with the Velocity stacks for a couple of days and see how it goes... I'm just curious and I like removing things ;-)))

I've also always disliked the massive black plastic airbox, aesthetically. I'll let you all know how it runs...

Note to self: don't request any more photo postings from beardyweirdy.

[beardyweirdy@me.com_imp]

Whoa there....

"Put it this way- I could have bought them if I wanted to, but I think they are way too big for the bike's needs even with the cams I am going to install."

What new cams??

This is exciting. How far have you got with this?
I'd love to run smoother cams. I'm sure my messing around (99 Rwhp) has exacerbated the miss-timed valve opening they claim to have built in for character. It may be all in my head but I'd love to know if 'regular' timed cams would feel better.

On another note, I've got TSR Air Intake, Air Funnel and Cat free pipe mods and it pulls clean and strong from naught to limiter. It may be to do with the AutoTune I have fitted tho.

I'm having a day in the garden and removing the airbox today. I'm going to just run it with the Velocity stacks for a couple of days and see how it goes... I'm just curious and I like removing things ;-)))

I've also always disliked the massive black plastic airbox, aesthetically. I'll let you all know how it runs...

What exhaust are you using? Yoshimura?


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What exhaust are you using? Yoshimura?


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It’s an Arrow header, cat free and an Over Can.


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Whoa there....

"Put it this way- I could have bought them if I wanted to, but I think they are way too big for the bike's needs even with the cams I am going to install."

What new cams??

This is exciting. How far have you got with this?
I'd love to run smoother cams. I'm sure my messing around (99 Rwhp) has exacerbated the miss-timed valve opening they claim to have built in for character. It may be all in my head but I'd love to know if 'regular' timed cams would feel better.

On another note, I've got TSR Air Intake, Air Funnel and Cat free pipe mods and it pulls clean and strong from naught to limiter. It may be to do with the AutoTune I have fitted tho.

I'm having a day in the garden and removing the airbox today. I'm going to just run it with the Velocity stacks for a couple of days and see how it goes... I'm just curious and I like removing things ;-)))

I've also always disliked the massive black plastic airbox, aesthetically. I'll let you all know how it runs...

Note to self: don't request any more photo postings from beardyweirdy.

Note to self: don't request any more photo postings from beardyweirdy.



You asked for it really....




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Also... it goes really well! I took it for a long ish run, 150 miles on Sunday morn. Thru fog and high speed motorway as well as sunny, country lanes and she ran great. Fueling was spot on. Pulled well from nothing in any gear and the top end rush felt really strong.
I’m leaving it like this for a bit


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[PowerDubs_imp]

If I remember correctly, you have the auto tune? If so, I’d let it run and see what the changes are. If it adds fuel, you’ve added air- which is power.

Looks great - I’d just rubber band some pieces of nylon stockings over each to keep out debris.

How does it sound? Should be louder and more aggressive in tone as you will hear individual intake pulses.


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[beardyweirdy@me.com_imp]

If I remember correctly, you have the auto tune? If so, I’d let it run and see what the changes are. If it adds fuel, you’ve added air- which is power.

Looks great - I’d just rubber band some pieces of nylon stockings over each to keep out debris.

How does it sound? Should be louder and more aggressive in tone as you will hear individual intake pulses.


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It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



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I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


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[chync_imp]

If I remember correctly, you have the auto tune? If so, I’d let it run and see what the changes are. If it adds fuel, you’ve added air- which is power.

Looks great - I’d just rubber band some pieces of nylon stockings over each to keep out debris.

How does it sound? Should be louder and more aggressive in tone as you will hear individual intake pulses.


Sent from my iPhone using Tapatalk

It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



Sent from my iPhone using Tapatalk
I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


Sent from my iPhone using Tapatalk

It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



Sent from my iPhone using Tapatalk
I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


Sent from my iPhone using Tapatalk
You say you are running a little lean after taking the air box off? There is a setting in the autotune for how much you will allow it to adjust the mix. I'm wondering if you need more fuel than the setting will allow until you apply the changes and run again.

[PowerDubs_imp]

Running lean is bad. I’d adjust the trims immediately after any major changes affecting airflow.

Cams are still being made. I’m currently on a tour of several countries in Europe so I in no rush.

Sucking anything into an engine is bad, but I’d definitely have something. There- oiled foam socks would be best, but for short term I would be ok with pantyhose.


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[beardyweirdy@me.com_imp]

If I remember correctly, you have the auto tune? If so, I’d let it run and see what the changes are. If it adds fuel, you’ve added air- which is power.

Looks great - I’d just rubber band some pieces of nylon stockings over each to keep out debris.

How does it sound? Should be louder and more aggressive in tone as you will hear individual intake pulses.


Sent from my iPhone using Tapatalk

It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



Sent from my iPhone using Tapatalk
I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


Sent from my iPhone using Tapatalk

It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



Sent from my iPhone using Tapatalk
I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


Sent from my iPhone using Tapatalk
You say you are running a little lean after taking the air box off? There is a setting in the autotune for how much you will allow it to adjust the mix. I'm wondering if you need more fuel than the setting will allow until you apply the changes and run again.

It's the duck's guts..... If anyone will get the Mad Max Interceptor ref.
(If not, you can see it here: https://www.youtube.com/watch?v=8bQzkdK2ha0)
Sounds demonic at full tilt and you can hear it gulping air low down.

I checked the Autotune when I got back and the trims were +fuel. It's also running a bit leaner I think as I'm getting more MPG.

I'm going to run it a while longer then maybe apply the trims and see what happens.

I must say the bike just keeps getting better...

So, what's with your new cams Power Dubs?



Sent from my iPhone using Tapatalk
I was going to put something over the mouths but was concerned that they might get pulled into the throttles. Thought about some foam filters but seems such a shame to cover those beauties up...

Sorry, I’ve hijacked your thread something rotten!
So... the cams? ;-)


Sent from my iPhone using Tapatalk
You say you are running a little lean after taking the air box off? There is a setting in the autotune for how much you will allow it to adjust the mix. I'm wondering if you need more fuel than the setting will allow until you apply the changes and run again.
The trims are asking for single figure adjustments and none in some places. Just off the throttle is weakest.

I've got the trims set to +/-20 I think, although I had better check that... thanks for reminding me.

Running lean is bad. I’d adjust the trims immediately after any major changes affecting airflow.

Cams are still being made. I’m currently on a tour of several countries in Europe so I in no rush.

Sucking anything into an engine is bad, but I’d definitely have something. There- oiled foam socks would be best, but for short term I would be ok with pantyhose.


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'Lean-er' I should have said. Not dangerously so, I would say. Just more Lean than before. Which is not surprising. I have the Target AFR's set from 13.2 -13.6 across the range, so not set overly lean to start with.

That said, as Chync said, if the Autotune was doing it's job then then I shouldn't see a difference in the MPG I guess.... unless it's holding back the adjustment and I've set it lower than +/-20. That's how it's set from Std.
I'll check it out tomorrow and let you know...

Fine wire mesh? I've heard it can mess with the airflow, but agreed I'm not altogether easy with them just open...

When you've finished your 'Grand Tour' I'll be very interested to see how you get on with the new cams.