2014 / 2017 airbox snorkels

[PowerDubs_imp]

By intake kit, do you mean the tsr metal velocity stacks?


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[jtopiso_imp]

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.

Nice and educative post.

One question: the CB snorkel seems to have two paths for the air. Is there a flap valve downstream, so it's a long path/short path variable intake? Ir is just two different paths, so the engine will breathe through the easier path it can at each rpm?

[teamvisegrip_imp]

Powerdubs... Yes I got both items to install this winter TSR Air Filter Kit and the TSR Intake Velocity Stacks. Already have the Yoshimura full exhaust fitted.

Waiting patiently to see what you get with the mods you do and actual numbers from a dyno.

Of course I will do the reflash but I sure wish I had your resources to measure actual gains. Maybe I will need to find a competent person in my area to do this. I have a guy that does the tuning on my modified carbureted bikes... not sure he does the ones with fuel injection. I will need to ask him some day.

Again... waiting excitedly to see your numbers.

[PowerDubs_imp]

Powerdubs... Yes I got both items to install this winter TSR Air Filter Kit and the TSR Intake Velocity Stacks. Already have the Yoshimura full exhaust fitted.

Waiting patiently to see what you get with the mods you do and actual numbers from a dyno.

Of course I will do the reflash but I sure wish I had your resources to measure actual gains. Maybe I will need to find a competent person in my area to do this. I have a guy that does the tuning on my modified carbureted bikes... not sure he does the ones with fuel injection. I will need to ask him some day.

Again... waiting excitedly to see your numbers.

Check here to see if there is a shop close enough to drive to for you-

http://dynojet.com/dynocenters/dynojet-m...nters.aspx


How does the bike sound without a cat? That is my biggest fear- many cars get raspy and sound like crap when the cat is removed.

I'm not sure I would do the TSR velocity stacks on an otherwise stock engine. Like anything else on a motor- too big is noo good! That is true for intake runners, throttle bodies, cams, exhaust pipe diameter.... really easy to throw money at parts a shop is more than happy to sell you- and make the bike run worse, or be slower in reality even though you 'feel' it is fast (Due to a lighter wallet )

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.

There is a reason I modified the stock ones instead. Modern engines are soo well designed (CAD, flow bench, simulators and actually factory testing) that there typically are no inherit flaws to speak of. No low hanging fruit.

The gains to be made on this engine are removing what the factory put there on purpose- from the simple such as tame final drive gearing, quiet as a sewing machine muffler, to more advanced (regulated) emission stuff like the cat, and lean fueling- which also means really really tame camshafts.

For reference the TSR 'funnel' are 35mm which they proudly proclaim are the same size as the TB. See anything wrong with that? They literally are taking the velocity out of a velocity stack. There is a reason their website says 'race only'. Sure they show a dyno chart- WOT. What happens at partial throttle? Whoops.


Give me a minute- I'll dig around for pics and update the post to show you what I did.
My stacks. Started with-




And then did this-















Unlike the TSR- I am keeping the exact same factory lip shape, same intake diameter, same outlet diameter... just removing what I believe to be an intentional midway choke point.

And since these are available dirt cheap and are plug and play with no modification needed (holes drilled in airbox) I have nothing to loose but time.




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[teamvisegrip_imp]

Powerdubs... I bought the TSR parts after PMing a guy that has installed them. He said the bike ran amazing and smooth power through out the rev range.

Will I install these items? Who knows. I just made sure to get them since they were out of production at this time.

As for the sound of the new pipe... I ran it for @ 2 minutes after I installed it to be sure there were no leaks at the gaskets. I have yet to actually ride the bike. right now I am stuck working on a ship till the beginning of July.

I hated the looks of the big chrome pipe and loved the looks of the Yoshimura pipe. Always loved the looks of these pipes. So it was the first thing I added to the bike.

So time will tell what I do this winter. LOL!

[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.

Nice and educative post.

One question: the CB snorkel seems to have two paths for the air. Is there a flap valve downstream, so it's a long path/short path variable intake? Ir is just two different paths, so the engine will breathe through the easier path it can at each rpm?

No flap valve.
I have only theories on the dual tube design...no facts.

[PowerDubs_imp]

My guess would be sound and velocity.

[jtopiso_imp]

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


Sent from my iPhone using Tapatalk

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.

Nice and educative post.

One question: the CB snorkel seems to have two paths for the air. Is there a flap valve downstream, so it's a long path/short path variable intake? Ir is just two different paths, so the engine will breathe through the easier path it can at each rpm?

No flap valve.
I have only theories on the dual tube design...no facts.

No flap valve.
I have only theories on the dual tube design...no facts.
share it, please!

I'm sure we can learn something.

My makeshift theory (as I've just learnt there is no flap valve), is that two different lengths avoid a resonant frequency at the working speeds (i.e. better sound in the whole range).

My makeshift theory number two is that the two lengths work in parallel* simulating a longer length (some effect of multypling both natural frequencies to the first common harmonic).

(* I always misplace the double "l", if any...)

[chync_imp]

Hard to say.

Smaller ports tend to increase velocity.

Larger ports can flow more ultimate cfm.

Longer runners tune for lower rpm, shorter lengths= higher.

The ‘bowl’ on the end may act like a plenum a bit. Smaller equals throttle response, larger equals better top end breathing.

I don’t expect the difference on the horn to make any drastic difference on it’s own.

I also have the TSR plate that replaces these horns. I will be testing and comparing all 3 on the dyno.




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Please post the results. I replaced my snorkel with a tsr inlet. Curious to know if it makes a difference.


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[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...