Wind Screen Holes

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by dzrtracin, May 2, 2005.

  1. sakurama

    sakurama on an endless build

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    I bought two of the NACA 2" ducts after reading this post and the endless posts in the GS list (love those guys) and after a short ride today I can say that it works. I'd tried a few things to stop the awful vibration I got with the Arai XD visor all to no avail. This did it. It's quiet - at least up to 80-90 or so but for average cruising it's smooth air. I'll put up some photos tomorrow.
    #41
  2. Pantah

    Pantah PJ Fan from Boston

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    I am glad to hear that sakurama. I drilled a couple 1" holes in my screen and it helped somewhat with the turbulence. But then I didn't really have turbulenced as much as a vibration at Interstate speeds that I thought would tire me on the long trips. After cutting the holes I still have a little vibration (But definitely less vibration) with either my Arai XD (peak removed), or my flip face HJC. If making bigger holes will eliminate the vibration, I'll be cutting some more. Thanks.
    #42
  3. K2m

    K2m ....58....

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    Now this I want to see........ (Some sort of BOUNCE WALL effect)

    2 years ago when I was fuel injecting my R80GS I came across your web sight and that totaly desirable R90s Gregor....... Very insparational!

    Did you ever get around to hoting up the motor? I kept checking back for part 2.

    Have you tryed the 336 cam....... what a hoot

    Blew me out to see you had got a 950..... me to

    And when it comes to cameras....... I have a mint 78 Nikon F2 Picked it up in a bazzar in Tehran city $300 US it's almost new. Iran is a great country for mountain climing.

    Enough waffel...... Please post thoes pictures :thumb
    #43
  4. sakurama

    sakurama on an endless build

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    [​IMG] [​IMG]

    I wrote a little blurb on what I did and put up a page of on the ducts along with some other mods I'm doing to the 950 (hit the "back" button. Not much new to anyone who reads this list since I found most of it here but pictures are nice so hopefully it helps someone.

    As for the ducts: They cured my buffeting problem with the XD thank god. They look kind of cool too. I don't feel much from them under the screen but the air that comes off the top is smoother. Maybe it helps equalize the pressure differential between the two sides and that smooths the air. Works for me though.

    Gregor

    PS No, it keeps getting pushed behine other projects. My friends and teammates are egging me on to get it ready to race at Mid-Ohio this summer... Hmm. We'll see.
    #44
  5. motoman250f

    motoman250f Been here awhile

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    where did you get those ducts from? If you stand up and sloutch down is there dirty air somewhere that your just not in or does the ducts clean up the dirty air? Did the ducts just move the dirty air to a different spot is what Im asking?
    #45
  6. AntWare

    AntWare Lost In Translation

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    have you read pages 1 & 2 :lol3
    #46
  7. sakurama

    sakurama on an endless build

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    Yeah, Antware posted a place to get them. I think I posted the link on my page too. Oh, thanks Antware - you got me going on this.

    It did move the dirty air to a new spot. Can I show you on the doll where the dirty air touched me?

    Sorry.

    No, it seems to be smoother overall. The transition from sitting to standing goes from slow clean air to fast clean air. The buffeting seems to be gone or so noticably decreased as to seem gone. I guess it will take a few more people doing this to really weigh in. I'm happy as I was trying to decide what to do about the cross country trip to the Moto GP in July. I wanted to do it from Colorado to Cali on dirt but I didn't want to suffer with the XD on the pavement sections but now I don't have to. Bliss!

    Gregor
    #47
  8. K2m

    K2m ....58....

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    Thats a great movie.....NAKED......I chose something else instead. .... A FUCKING BIG MOTORBIKE......:evil
    #48
  9. AntWare

    AntWare Lost In Translation

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    ..."Naked" is a brilliant film...but the quotes from "Trainspotting" :lol3

    ...and it's fooking :D
    #49
  10. motoman250f

    motoman250f Been here awhile

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    OOPS,, guess im being lazy. Thanks for the pics. that really gives me an idea of where to place them. I figure on doing this in the next month.. maybe we can get a few to chime in and give a real solution. My laminar lip created more dirty air and didn't work out but these ducts may help that too. if so it would be a perfect setup for me,, no buffeting and little when I want to hit the open road with the laminar lip!!!
    #50
  11. Katoum

    Katoum Adventurer

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    I gave McKinney a phone call and they are sold out and could not give me a date when they would have stock. Also they only available in carbon fibre, (expensive). Would anyone know of another supplier that has stock. I would like to get a set installed by June for a upcoming BC Backroads trip.

    #51
  12. KTMax

    KTMax Ninth of the Nazgul

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    They quoted us some 25 bucks for the 2" carbon duct. That's pretty cheap for carbon I'd say...

    Besides, unless you paint them glassfiber looks horrible too.
    .
    #52
  13. rocker59

    rocker59 diplomatico di moto

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    Hey fellas,

    Thanks for the inspiration in this thread. I've experienced the same problem with my Guzzi Quota Touring Windscreen and decided on a plan of action based on the info in this thread.

    Here's the report on my little experiment:


    Well I bit the bullet and vented the new Quota Touring Windscreen
    today! The idea of drilling on a $200+ piece of plastic had me a
    bit worried! "Action produces results", so I broke out the old hole
    saw and 1/2" drill and got to work.

    Measured and marked first with a ruler and sharpie pen. I started
    with three 1-1/2" holes just up from the bottom Then drilled a 1/16"
    pilot hole 2-1/4", on center up from the bottom of the screen. Next
    I chucked up the hole saw, and with a piece of wood behind the still
    mounted screen, drilled them out to full size. The holes were so
    clean that it will only take a bit of light sanding to smooth them
    out to perfection.

    Now for a test ride. About ten miles at speeds upto 70mph. A
    noticeable difference, but still getting a lot of buffeting about my
    ears. The test ride was done sans helmet to increase my ability to
    feel any changes. A noticeable change but not enough. Back to the
    house, then!

    I decided to add two more holes above the first three. Same size,
    same process of measuring, drilling and sawing. Now on to the
    second road test.

    Same stretch of highway at speeds upto 70mph. An even more
    noticeable reduction in the annoying "popping" type of buffeting I
    was getting around my ears. Edges of "the envelope" seem much
    smoother.

    Don't get me wrong, it's still a bit noisy, but this
    first modification to the touring screen has made a noticeable first
    impression!!! I'm gonna go for a "real" ride tomorrow with ATGATT to
    try and further gauge the effectiveness of this modification.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
    #53
  14. rocker59

    rocker59 diplomatico di moto

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    #54
  15. Tim McKittrick

    Tim McKittrick Long timer

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    Ok, this has nothing to do with windshields but as long as the subject of vorticies keep cropping up I thought some of you might find it interesting...... too bad it takes more air pressure than could be generated by sticking one's head into the windstream or we would all have a cool new way to heat or cool our helmets.

    http://www.visi.com/~darus/hilsch/
    #55
  16. Stephen

    Stephen Long timer

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    Rocker:
    Nice illustration. Certainly easy to visualize riding, oh, say a 2004 Road Glide. Exactly what you feel. Much higher frequency, lower amplitude oscillation on the 95, but IMHO clearly what's going on.

    Tim McK:
    Okay, that's fascinating. Brings out the Mad/Garage Scientist in me!
    #56
  17. sakurama

    sakurama on an endless build

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    Update:

    I rode out to Laguna and back and we did all sorts of riding in all sorts of weather. The naca ducts solved all the buffeting problems I had with the 950 completely. Depending on the surrounding wind or cross wind the airflow was either very smooth or completely quiet.

    I rode 4000 miles with an Arai XD which isn't known as the quietest helmet but I had no problems from 10 - 120mph during the entire trip. Before the ducts I couldn't handle riding with the XD for more than 30-40 miles as it vibrated so bad.

    Great solution.
    #57
  18. pfb

    pfb Riding, not skiing.

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    Where did you get your ducts from? Are they CF or just made to look like it?
    #58
  19. pfb

    pfb Riding, not skiing.

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    Never mind. Looked at your web page and saw the info on where you ordered them...
    #59
  20. FastEddieB

    FastEddieB Been here awhile

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    About 5 days into my ongoing Canada trip, I tried standing on the pegs to get above the buffeting. It was amazing how much things quieted down.

    With the stock shield it was so noisy (I'm 6'1") it was interfering with my ability to clearly hear music/news (via earbuds).

    Anyway, I just pulled the damn thing off:

    [​IMG]

    I considered buying a Dremel tool and trimming it, but I get buffeting if I even slouch a little - I thing even an inch or so of screen would make things worse. For now I've got the stock shield strapped on the back (I don't think it would be worth it to ship it home).

    So far, I don't mind being naked (!)

    BTW, had the exact same situation on my R100GS. Needed either a Parabellum to get behind or no shield at all:

    [​IMG]
    #60