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Two into One Exhausts

  • Retroman
    Retroman
    6 years ago

    RB racing LSR come highly rated with many "options"

    Quite an interesting website to boot !

    Once again the forum will not let me attach or post links ?




  • FXDF08
    FXDF08
    6 years ago
    For what it's worth, I had Fullsac stepped header pipes on my FLTRX. Ceramic coated, two into one into two. Had 254e SE cams and fairly standard SE Protuner tune (no dyno time) with K&N filter. SE mufflers. Bike ran pretty bloody amazingly and would do an honest 190+ kph. Speedo showed over 200. 
    Doesn't help your question I suspect, but I subscribe to the physics of stepped headers.  I'll watch this post with interest. 
  • speedzter
    speedzter
    6 years ago
    I don't really go along with the stepped header theory .

    When you increase the diameter of the pipe by "stepping" up the size, what happens to the gas velocity and temperature, not to mention turbulence.
    The gas velocity slows (bad) due to the increased volume, the temperature decreases (bad) , and it creates turbulence (bad).
    Now if you were to do it by increasing the diameter properly (taper, with no steps) it may be a different story.
    The one thing a stepped pipe can help with is reversion.

    Anyway, that's my theory !

  • Ratbob
    Ratbob
    6 years ago
    I'm overseas so don't have access to my ref papers but there are plenty of interesting sites, google up exhaust calculators etc.
  • Retroman
    Retroman
    6 years ago

    Should have mentioned in the last post.

    I have worked on a couple of bikes , one Softail and one Dyna , each with a different LSR 2:1 system.

    Both very well made , and one was not too loud at all. Not "legal" but way less likely to get an EPA notice.

    They are rare in WA , only 2 I've ever seen in the metal.

    Saw plenty at Daytona Bikeweek in 2011

  • Krash Kinkade
    Krash Kinkade
    6 years ago
    hilly, a lot of people swear by stepped headers, but I have not had much time to test that out so can't say.
    just as your in Queensland and I remember gonzo made lots of pipes for mark hacker when he drag raced twin cam Harley's they spent a lot of time at track and with dyno and gonzo was making and designing the pipes, should look him up. if you just go with what everyone else use you just get the average result. go your own route and have a special set up no one else has.
  • Gunsou
    Gunsou
    6 years ago
    Check out the dyno page on the Hammer Performance web site  Patriot Defender 2>1 makes huge power and they are tuneable quiet when you need and deep when you can
    http://www.hammerperf.com/xlexhaust.shtml

    I have a set on with a big breather air cleaner and ThunderMax and it beats the mates SE stage 2
  • MMVTwin
    MMVTwin
    6 years ago
    Hilly how are you?
    from my experience with my SPF stepped 2;1 
    With my 120rx it made the best power and torque figures from any 120rx that had been wheeled onto Deano's Dyno. His comment was that the pipe is what had made the difference, it kept making power when he kept pushing the rev limiter out
    now with the same pipe on the Streetbob with the stock 103 in it made 95 tor and 80hp( no tune just a power run) this was a very linear torque curve and HP turned back at 5500rpm, not like the 120rx it made power all the way to the stops.
    I thought that on the 103 it would be like doing a lung function test but it wasn't the case. this pipe that is stepped to 2" didn,t affect a stock motor at all and certainly works with the 120cuber
    so what is see is that these type of pipes don't do any harm to the smaller cub motors and only work better the more you throw at them.

    Have a mate over here building some nice 2;1 stepped header exhausts and did a comparison against a V&H pipe in just a cam'd 103 and it showed gains over the off the shelf pipe, but I believe if you were to compare the same two pipes with on one of my 107 builds you would see the gap between the two pipes widen
    Ando

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