Help me understand this

Discussion in 'Engine, Fuel and Exhaust' started by 11bdad, Jul 8, 2011.

  1. 11bdad

    11bdad Member

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    Bought a new 2010 FXDC which ran as expected.
    1. Added XIED's. Ran fine, lower temps, no decel popping.
    2. Added Rush Slash Cut slip on's (1.75 baffle) Runs great, sounds great, but decel popping (not horrible, but noticeable).
    3. Disconnected XIED's. Same as above, but with less decel popping.

    Why is the decel popping more pronounced with the XIED's? I've gone from the lean factory AFR (14.7:1) to a richer AFR (13.8:1). There are no exhaust leaks. I cranked the bike up in my garage with the lights off, covered the headlight with a towel, and went over the entire exhaust system with a big smoking cigar and a flashlight. Had a buddy working the throttle, and there are no leaks. I've already resigned myself to the fact that I'll need another AC and some type of tune. Is a 13.8:1 AFR still too lean in closed loop?

    Thanks
     
  2. dbmg

    dbmg Experienced Member

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    Its a byproduct of aftermarket exhaust. Had Rush 1.75 on my EG and did same thing. The bikes burble a bit with OE exhaust on decell also, just not as noticable.
     
  3. glider

    glider Veteran Member

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    dbmg hit it on the head. When you use lower restriction mufflers the popping can be more pronounced. Has more to do with the mufflers than the IED's.
     
  4. Hoople

    Hoople Account Removed

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    Granted I have never measured the difference a set of XIED's would make using an Infra-Red exhaust analyzer, but I would bet you won't see a swing of 14.7 to 13.8 in your A/F ratio..

    Think about it. A narrow band O2 sensor's ENTIRE operating window is from 14.1 to maybe 14,7. How can you offset the window beyond it's operating perimeters? I really think you would be lucky to actually see a shift of .3 of 1 point.

    Don't misunderstand me. I like the Nightrider website and he has a lot of interesting info to share.
    But I also think you need more of a shot than they can provide. They also will provide you with NO (absolutely none) enrichment during wide open throttle. Indeed something you want no part of.
     
  5. 11bdad

    11bdad Member

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    I wasn't aware of the operating range of the stock O2 sensors. Thanks for that bit of info. That makes me wonder about the claims made by Nightrider concerning the XIED's. Well, the XIED's did work well with my stock exhaust since there was a noticeable drop in temps and low end throttle response. I hooked the XIED's back up, and am able keep the popping to a minimum with the throttle and gear selection.

    Thanks guys
     
  6. glider

    glider Veteran Member

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    There are many that bought into the XIED's and soon after went to a tuner never the less because they just don't do too much. For stock config, they'll "get by".
     
  7. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    I wonder if a call to Dobeck would solve your problems.