1. After 20+ years it's time to pass the torch. If you are interested in acquiring this forum please contact support@cv-performance.com for details. Any spam will be reported and blocked.
  2. Welcome to Bike Talk, a forum for all bikers and motorcycle enthusiasts. If you are new to Bike Talk, be sure to register for free and join the conversation.

    There's always someone around willing to help out with questions or give a friendly wave back. All Harley and metric riders are welcome.
Bike Talk Motorcycle Forum is For Sale Welcome to Bike Talk

Velocity stack

Discussion in 'Motorcycle Tech Talk' started by fxrsrules, May 20, 2007.

  1. fxrsrules

    fxrsrules New Member

    Joined:
    Jan 3, 2005
    Messages:
    61
    Likes Received:
    0
    Location:
    Sacramento Ca.
    I have a fxr with a S&S 124 in it with a K&N air cleaner on it. I was reading here a while back and sombody was saying how much more performance they got out of a screamin eagle air cleaner kit. I don't know if he/she/everybody was talking about a K&N air cleaner a velocity stack or somthing new that came out. I have been wondering for a while if I was geting enouph air and if changing to a velocity stack would make a huge diferance in all round riding or if they are good for wide open only. Anybody got any suggestions.
    fxrsrules, May 20, 2007
    #1
  3. maxpower_hd

    maxpower_hd Active Member

    Joined:
    Jun 16, 2004
    Messages:
    466
    Likes Received:
    0
    Location:
    Massachusetts
    Air Cleaners

    I have a K&N filter on my 99 Fatboy with a Sidewinder, forward facing air cleaner assembly. I wouldn't call it a "velocity stack". I was always under the impression that velocity stacks did not utilize air cleaners, which I would not recommend. I could be wrong.

    I noticed an improvement when I added the Sidewinder to my MickyRooney (Mikuni) carb. However I wouldn't call it a huge improvement. I mainly liked the look and wanted something that didn't contact my knee at all. This one sits forward so there is no contact what so ever. You also have to take care to keep it clean since it is right out there in the elements.

    My buddy has a Hypercharger on his Softail and it's right, smack dab in the way and my knee basically rests on it. I have a bad knee so this is basically intolerable for me. He doesn't seem to have an issue with it. His is also a Mikuni carb. I'm pretty sure it is even worse on a S&S. They stick out a bit more than the Micky.

    Hope that helps.
    maxpower_hd, May 21, 2007
    #2
  4. kenfuzed

    kenfuzed Administrator Staff Member

    Joined:
    Jan 1, 2005
    Messages:
    10,513
    Likes Received:
    140
    Location:
    Las Vegas NV
    I'm not a big fan of velocity stacks. They are better suited for racing and choppers with enough stretch to get it out of the way your knee. For regular street use I've never seen any advantage to using them.

    SE, similar air cleaners (Arlen Ness, etc), Forcewinders, and hyperchargers are probably the better breathing assemblies out there. Filters like the K&N run a close second and more than adequate for most street use. I'm assuming you already have an S&S carb and air cleaner, in which case the S&S backing plate w/K&N is as good IMO as any screamin eagle kit.
    kenfuzed, May 21, 2007
    #3
  5. fxrsrules

    fxrsrules New Member

    Joined:
    Jan 3, 2005
    Messages:
    61
    Likes Received:
    0
    Location:
    Sacramento Ca.
    Thanks for the comeback Kenfused and Maxpower on my question. Yes I do have a S&S carb, backing plate, face forward and K&N filter. I need more power like I need another hole in my head anyway! Once again this bike is ruling my life as stated in my name here.
    fxrsrules, May 22, 2007
    #4
  6. Ted

    Ted New Member

    Joined:
    Feb 4, 2007
    Messages:
    90
    Likes Received:
    0
    Location:
    Sebastian Fl.
    Ted, May 23, 2007
    #5
  7. cowboy

    cowboy Moderator Staff Member

    Joined:
    Apr 19, 2006
    Messages:
    9,926
    Likes Received:
    50
    Location:
    Alvin TX
    ted look's to be a good read , I checked out the prices $299 for the complete set up & $69 if you have the stage one set up already, they say 100% money back if your not happy with it
    :cool:
    cowboy, May 24, 2007
    #6
  8. skull2007

    skull2007 Active Member

    Joined:
    Feb 5, 2007
    Messages:
    731
    Likes Received:
    0
    Location:
    middleburg, pa
    wait and see

    i'll be waiting to see if it really works. i note that with the "money back thing" you have to send them dyno results:puke: i'm more interested on what happens on the road. I have bad vibes about this one. sounds like another gimmick. good luck, and please share the results. promise i won't say "i told you so":rolleyes:
    skull2007, May 24, 2007
    #7
  9. kenfuzed

    kenfuzed Administrator Staff Member

    Joined:
    Jan 1, 2005
    Messages:
    10,513
    Likes Received:
    140
    Location:
    Las Vegas NV
    Interesting... if its true. I had the opportunity many years ago to visit a lab doing flow tests on various intake systems, both carburetors and throttle bodies. While I'm not an engineer or physicist it was fascinating to see how they could take measurements of everything conceivable when it came to air flow. This setup was designed to test every aspect of the intake and fuel atomization as it passed through.

    What I found to be of the most interest was no matter how they swirled the incoming air it made little difference once it passed the venturi and reached the intake manifold side. The only real difference was when a blower was used to maximize the inbound air to a velocity greater than that of air normally entering at maximum speed. However I don't think that would ever apply to our motorcycles in any practical application.

    I was told that the design of the venturi or throttle body is the greatest determining factor for how air flows into the intake manifold. How turbulent the air flow is before entering had a very small part, as once it passes through the controlled environment of the venturi it takes on its own turbulent pattern.

    As far as the fuel becoming atomized, changes in the actual spray pattern, pressure, duration, and intake manifold design and vacuum had far more to do with this than the pattern of air entering the air cleaner.

    Ken's crazy analogy:
    You are riding down the road at 60 mph. A bee traveling at you rebounds off your headlight, into your mouth, bounces left to right off your teeth, hits the back of your throat, before you swallow it?
    That same bee comes straight at you, into your mouth, slams into the back of your throat, before you swallow it.

    In either case, did you swallow the bee any faster or with any more efficiency? Not likely, though the bee sting on the back of your throat may have felt more intense :roflmao:
    The point is that no matter how fast or turbulent that bee entered, your throat still controlled how the bee would be swallowed.

    Thats just my 2 cents with a bee sting thrown in :p
    kenfuzed, May 24, 2007
    #8
  10. Slimjim

    Slimjim Active Member

    Joined:
    Jul 22, 2006
    Messages:
    433
    Likes Received:
    4
    Location:
    Georgia
    Even I can understand that one.
    Slimjim, May 24, 2007
    #9
  11. maxpower_hd

    maxpower_hd Active Member

    Joined:
    Jun 16, 2004
    Messages:
    466
    Likes Received:
    0
    Location:
    Massachusetts
    Thanks for dumbing that down for us Ken. :roflmao:
    maxpower_hd, May 25, 2007
    #10
  12. Ted

    Ted New Member

    Joined:
    Feb 4, 2007
    Messages:
    90
    Likes Received:
    0
    Location:
    Sebastian Fl.
    Now Kenfuzed
    Think about it, If you had that little screen in front of your teeth. You would just lick your teeth and swallowed and never lost a breath stroke. We have Love Bugs in Florida. After a wile they tast like fish. I think Ive been riding to long. .Later Ole Ted.
    Ted, May 25, 2007
    #11
  13. chucktx

    chucktx Moderator Staff Member

    Joined:
    Jul 5, 2005
    Messages:
    12,545
    Likes Received:
    10
    actually, ken, your anology actually points out something else......the first bee took longer to get to the back of your throat,because of all the twists,turns,ect. than the bee with the direct flight in. now, back to old school.........put a scoop, with no restrictions on the ol streetrod.....more power, and preformance. anything put between the intake and outside air is a restricter.......anything! we allready have a filter of sometype....why add more restrictions of airflow. i would spend my money on hiflow filters instead of some "snakeoil".........jmho
    chucktx, May 25, 2007
    #12
  14. fxrsrules

    fxrsrules New Member

    Joined:
    Jan 3, 2005
    Messages:
    61
    Likes Received:
    0
    Location:
    Sacramento Ca.
    Thats right! The more restrictions the less air flow.. so why would putting a screen on my mouth that is turned sidways to the direction that I'm going and taking off my face forward air intake filter make the bees, love bugs, dirt ect... flow into my throat any faster while most of it (air and bees) are all flowing past it and on their way to parts unknown. Air is not being ramed into it as a scoop or blower would do. If it was in a closed in area like under a hood of a cage I could see it. I was looking at what's new at S&S It's called a single bore tuned intake. $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ but then again would it realy make that big a diferance?
    fxrsrules, May 26, 2007
    #13
  15. bikerjim1

    bikerjim1 Moderator

    Joined:
    Feb 16, 2005
    Messages:
    794
    Likes Received:
    0
    Location:
    Liberty Hill Texas
    Well,

    I don't know about alla that hooplah bout' bees, screens and the taste of fish (well that one I may:p ) but I can attest to when I changed my stock air cleaner out with a Forcewinder, there was a noticable difference with performance. Never had her dynoed, but I like the difference.
    bikerjim1, May 29, 2007
    #14
  16. kenfuzed

    kenfuzed Administrator Staff Member

    Joined:
    Jan 1, 2005
    Messages:
    10,513
    Likes Received:
    140
    Location:
    Las Vegas NV
    All very good points. Anything that replaces the stock air cleaner will certainly increase flow, including Forcewinders, Hyperchargers, scoops, etc.
    However placing a screen type device in the air path to allegedly alter the flow and reduce turbulence I think is just snake oil.

    Increasing overall flow should be enough to improve any ride, but attempting to condition the incoming air pattern is a bit overboard when it comes to street use.
    kenfuzed, May 29, 2007
    #15
  17. whacker

    whacker Active Member

    Joined:
    May 7, 2006
    Messages:
    276
    Likes Received:
    0
    Location:
    Newaygo,Mi.
    I had one of those screens "fuel atomizer" on bike bike,took it off this year,seems to run better without it,I think they are just snake oil too.I think your valve has the biggest restriction in the flow pattern...My two cents....
    whacker, May 30, 2007
    #16

Share This Page

XenPorta © Jason Axelrod from 8WAYRUN.COM