Active Exhaust Module

Discussion in 'Dyna Models' started by DynaBob09, Sep 24, 2010.

  1. DynaBob09

    DynaBob09 Active Member

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    I bought the Service manual for my 2009 Fat Bob. In the section on exhaust it explains and shows pictures of the active exhaust module. It is an electric servo that contols a wire that opens and closes a damper that is built into the exhauset collector. Well, my bike does not have the servo, wire or damper illustrated??
    Any thoughts?
     

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  2. blademan

    blademan Active Member

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    I went through the same thing with my 07, after research I found out it is a system used in Europe. It is not on US bikes.
     
  3. DynaBob09

    DynaBob09 Active Member

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    I've heard about these on cars. Suppose to help low end torque with back pressure. I wonder if it has the same effect on the bike? Why in europe and not US. Unless it is a sound dampening system?
     
  4. Hoople

    Hoople Account Removed

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    I think that is what it is. Has nothing to do with power.
     
  5. DynaBob09

    DynaBob09 Active Member

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    I found this that explains what it does. We are not missing anything.
     
  6. DynaBob09

    DynaBob09 Active Member

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    Forgot the link....

    Cheap Bike Parts
     
  7. biscuit

    biscuit Junior Member

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    That's a feature on International market Harleys only.
    These bikes have what can be described as 'active' or opening Butterfly valves in the Air intake AND Exhaust systems.

    Basically,the valve opens at a certain rpm to increase intake/exhaust flow;and closes at about the rpm point that exhaust decibel measurements are taken.With the Exhaust valve in the closed position,the bike basically has a very restrictive 2into1 system.It closes off flow to the front cylinder muffler just AFT of the balance pipe.

    Seems to be a bit of a gimmick;if one fits an aftermarket A/C,the intake valve becomes superfluous;and so will the exhaust butterfly if one fits a Thundermax.Then it defaults to permanently open.
     
  8. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Kinda reminds me of ol' school testing tricks for meeting sound and emissions test ONLY at the points being tested and let the rest of the law be...uhumm..."COMPLIANT."