Home made Snorkel

Discussion in 'GS Boxers' started by rkleen, Oct 13, 2010.

  1. rkleen

    rkleen Adventurer

    Joined:
    Dec 2, 2009
    Oddometer:
    82
    Location:
    Monterrey, MX
    After my amusing experience crossing water, I decide to made a snorkel.

    Here is what I am doing to fit the GSA:

    Connector for air intake that fit the space on the right tank of the GSA:
    [​IMG]

    End connector that has an o-ring that will keep water off when attaching the extension:
    [​IMG]

    Extension attachment, connector and flexible electric tube:
    [​IMG]

    Connectors fited on the air intake:
    [​IMG]

    [​IMG]

    Snorkel with the other connector on one end, the one that will fit the air intake modified:
    [​IMG]

    [​IMG]

    [​IMG]


    And how it will be put on and off:

    [​IMG]

    [​IMG]


    This is the final product:
    [​IMG]

    Now, a final touch of black paint and install on the bike. Lets see how it works...
    #1
  2. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

    Joined:
    Feb 11, 2005
    Oddometer:
    82,412
    Location:
    Alexandria, VA
    I think you will find you just lost decent airflow even with the hose disconnected. You might consider one that, when not in use, leaves the opening more close to stock.

    On the other hand, maybe it wont effect it at all! :dunno

    Jim :brow
    #2
  3. timtimtim2000

    timtimtim2000 Adventurer

    Joined:
    Aug 5, 2009
    Oddometer:
    77
    Location:
    District of Columbia
    Nice snorkel! Let us know how that works for you. I'm interested to hear if airflow is affected when the hose isn't attached.

    Also, do let us know how you plan on reattaching the hose to your vacuum cleaner! :rofl :rofl
    #3
  4. rkleen

    rkleen Adventurer

    Joined:
    Dec 2, 2009
    Oddometer:
    82
    Location:
    Monterrey, MX
    Jim... I tought that also, since the stock has a small conic ending... (very slightly cone shape)

    I select a connector that has exactly the same diameter, taking into account that the air flow must be the same.

    Maybe if I work on the edge of the connector to make some cone shape and make the air go thru more efficiently when the snorkel is not connected...

    BTW... is worth to mention that this is not a vacuum cleaner hose, because vacuum hoses are corrugated and can interfiere with the air flow or make "dirty air". That is why I choose electric hose that is flexible, hot and water resistent and have a smooth finish inside... not corrugated. I have to cover it with black electric tape jus because the spray paint doesn't work on this material and I don't like the gray color :)

    This saturday we on the motorclub (www.2wheelsclub.com) will go for the revenge and will post on monday the result of this modification.
    #4
  5. Wallowa

    Wallowa Diver Down

    Joined:
    Nov 30, 2006
    Oddometer:
    6,078
    Location:
    NE Oregon
    Really want and need a snorkle set-up....could you photo and name each piece individually? And include where you might find one to buy? {not name of store, but type of store}

    I see several plastic parts but can tell what they are...

    Smooth hose ID is golden! Did not know that there was a flexible electric hose with a smooth bore....

    ID of OEM air intake horn seems tiny...perhaps a connector that fit 'over' that bell on the end would enhance flow?

    Thanks!
    #5
  6. Bill the Bong

    Bill the Bong Supern00ba

    Joined:
    Dec 20, 2006
    Oddometer:
    1,411
    Location:
    Kalahari South Africa
    I think that if the Uni-filter pre-filter that I sometimes stuff inside the snorkel has such limited effect, that minute amount of constriction is really unlikely to impact on airflow.

    Nice job!

    Bill
    #6
  7. Wallowa

    Wallowa Diver Down

    Joined:
    Nov 30, 2006
    Oddometer:
    6,078
    Location:
    NE Oregon
    I to have the Oz made UNI filter and I do use the pre-filter in the air horn...was told by Atlanta BMW that the pre-filter loses me 5hp...I could care less about that...fitting a snorkle over the pre-filter is another gig..I would put UNI pre-filter on the intake end of the snorkel...more for dust that water..

    Also the pre-filter will stop splashes of water but not of course a submersion..
    #7
  8. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

    Joined:
    Feb 11, 2005
    Oddometer:
    82,412
    Location:
    Alexandria, VA
    Of course, with the hose attached, significant airflow will be impeded. Ever try to breath through a straw?

    Not attached, hard to say for sure. A dyno may be needed to tell.

    Jim :brow
    #8
  9. Wallowa

    Wallowa Diver Down

    Joined:
    Nov 30, 2006
    Oddometer:
    6,078
    Location:
    NE Oregon
    Jim,

    If snorkel ID matches the ID of the smallest ID of the airhorn [bell at end] and snorkel bore is smooth I am not sure that any great amount of velocity would be lost or that volume over time would be lost or that it would suck up lots of Hp...breathing through a straw would seem a fair comparison if the snorkel ID was smaller than airhorn...for you to breath through a straw the size of your trachea is closer to his set-up...but hey, who knows!
    #9
  10. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

    Joined:
    Feb 11, 2005
    Oddometer:
    82,412
    Location:
    Alexandria, VA
    Venturi effect. If you pull air through a straight tube (meaning same sized for a significant length) you can only get so much air. Have a bell opening, and expanding tube behind it and you can pull in significantly more air at a higher velocity.

    [​IMG]
    See the shape of the opening, and then the expansion pipe behind it?

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

    http://everything2.com/title/venturi+effect

    Jim :brow
    #10
  11. ABuck99

    ABuck99 0.0

    Joined:
    Feb 21, 2009
    Oddometer:
    781
    Location:
    Georgia
    Not an alternate for a snorkle, but if you are using a UNI pre-filter or foam stuffed into the intake: an alternate solution -would be the OuterWears Prefilter for an CRF80- you can simply slip it over the end of the intake and zip tie in place- the pre-filter material repells water, and dirt debris pretty nicely, and has no effect on HP. Retail is about 14.95 but could be found for less Im sure. Mfg part number is HA-1088.

    http://www.outerwearsracing.com/faq.html
    #11
  12. Wallowa

    Wallowa Diver Down

    Joined:
    Nov 30, 2006
    Oddometer:
    6,078
    Location:
    NE Oregon
    Jim,

    Interesting ideas...you are saying that the external bell and restricted ID on the opening of the OEM airhorn creates a better air flow? Wow, that would be fun to test.

    But read the reference you posted....you can speed up gases/fluid through a restriction in ID but the pressure drops and the net is zero in moving more air into the engine..

    This low pressure is used in many applications to pull in fuel or other gases into the main stream of fluid/gases but none of that is applicable to the airhorn...like the sudden drop in compressed gas pressure and acceleration through a venturi [such as a SCUBA tank valve] can cool the gas enough to create crystals but the amount of gas going in and coming out is the same..

    From Wiki:

    "According to the laws governing fluid dynamics, a fluid's velocity must increase as it passes through a constriction to satisfy the conservation of mass, while its pressure must decrease to satisfy the conservation of energy. Thus any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is negated by a drop in pressure. An equation for the drop in pressure due to the Venturi effect may be derived from a combination of Bernoulli's principle and the continuity equation."

    Interesting topics...bottom line is the engine on my bike needs a snorkel to survive deep water crossings or ones taken fast with a bow wave...otherwise it is a huge PITA and possibly a busted engine..

    So I will give up a few ponies for a functional snorkel..and snorkels are in use on BMWs, I assume they are functional or they would not be used.

    Oh yes, the UNI pre-filter inverts into the airhorn bell [yes it uses a zip tie] and is an oiled foam...so it does shed some water...
    #12
  13. rkleen

    rkleen Adventurer

    Joined:
    Dec 2, 2009
    Oddometer:
    82
    Location:
    Monterrey, MX
    I am aware that it surely will kill some HP of power, but since this is a connect/disconnect snorkel, I guess that I don't need so many horses on the water bends!

    This is the final product-instalation:

    [​IMG]

    Lets see how the bike feels off-road, on the water crossings and in the slab.

    I'll come back after saturday, that will be the day of testing.

    Thanks for all your feedback!.
    #13
  14. 1coolbanana

    1coolbanana Long timer

    Joined:
    Aug 25, 2009
    Oddometer:
    5,433
    Location:
    NW Sydney, Australia
    Please let us know the results :D

    How did you clear the Telelever arm, between the tank and arm? Did you flatten out the tubing?
    #14
  15. rkleen

    rkleen Adventurer

    Joined:
    Dec 2, 2009
    Oddometer:
    82
    Location:
    Monterrey, MX
    Flaten the tube was my first choice, but don't wanted to reduce the air flow, so what I did was an curve shape with several connectors (45°, 90°) so they can get thru the little space that have the fuel tank, and between the telelever and the frame.
    That was, in fact, the amusing part!
    In the GS you have more room than in the GSA...
    #15
  16. GeorgeinVA

    GeorgeinVA Beemers Uber Alles

    Joined:
    Nov 1, 2009
    Oddometer:
    652
    Location:
    Warrenton VA
    Jim is dead on with the flow reduction. I was a finisher and used HVLP (high volume low pressure) spray guns. The length of hose is critical. If the hose was too long they restricted flow would result in poor atomization.
    Now how will it effect the bike in "real world" operation? We will have to wait for the ride report. I would guess a drop in top end and sluggish response. I would also guess much better waist deep water performance.
    #16
  17. 1coolbanana

    1coolbanana Long timer

    Joined:
    Aug 25, 2009
    Oddometer:
    5,433
    Location:
    NW Sydney, Australia
    Length causes restriction, absolutely.
    Bends also make a huge flow difference.
    The sharper they are the worse they restrict and cause turbulence.
    eg. large big radius bends affect much less than small radius.
    #17
  18. Tim2007

    Tim2007 Been here awhile

    Joined:
    Dec 7, 2007
    Oddometer:
    167
    Location:
    Oak Park, Ca
    I can tell you first hand that it WILL restrict airflow. I have rune the snorkel for ALOT of miles. But as you said if you are going to take off and put back on as needed, I think you will be ok.
    Bottom line, If this makes ytour river crossings, safer, it will have been worth it.
    Tim[​IMG]Here
    here is a picture of my snorkel. I bought the adapter from an inmate, James 99 or something like that, It worked very well, but it did cut down performance at the top end
    #18
  19. bonox

    bonox Tryin Hard

    Joined:
    Apr 5, 2006
    Oddometer:
    3,009
    Location:
    sydney
    at constant throttle, the ECU will make up for any change to the air intake by using the lambda sensor feedback.

    Let's face it - the GSA is a 100hp bike being used in water, not a 2hp bike being used on a racetrack. In my experience, guys looking for snorkels and riding BMW twins aren't generally the ones bouncing it off the limiter WOT.

    Who cares if you lose a few hp off the top that aren't going to get used anyway. Good luck to you rkleen - it looks like a really neat installation - great job.
    #19
  20. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

    Joined:
    Feb 11, 2005
    Oddometer:
    82,412
    Location:
    Alexandria, VA
    Very true. I wasn't trying to discourage the innovation, just bringing up a possible side effect, and then engaging in discussion. I think we all learned some here, and I am looking forward to the results!

    Jim :brow
    #20