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Cat's Meow

Discussion in 'Exhaust System & Fuel Delivery' started by sxcR12RS, Dec 31, 2017.

  1. sxcR12RS

    sxcR12RS New Member

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    2016-Granite w/ 2400 miles.

    This formula serves simply as (1) data point.

    RemusHeaderPipe + OEM_Muffler + BoosterPlug = Wow

    - 2-mpg better than stock (45 vs 43)
    - no pops in flog-mode
    - much throatier than stock w/ no rasp just sounds solid like a weldment should
    - noticeable improvement in low-end on/off/on power delivery
    - less shifting required
    - improved low end torque not yet evaluated for 2-up mode which was the driving element for change

    Been in lurk mode for several weeks since acquiring said bike - thanks to this forum for the good topic discussion which swayed how one spends their hard-earned money.

    Doing the happy dance.

    /Steve (Portland, OR)
     
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  2. Rocky R

    Rocky R Active Member

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    Why would you not add a freer flowing air filter? Removing the cat and even though using the restrictive OEM muffler you are still capable of flowing more air which the Booster Plug can compensate for on air/fuel. You can only exhaust out as much air as you can take in...
     
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  3. Aussie Import

    Aussie Import Well-Known Member

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    Is the restriction in air flow really the filter? If there is one it may be in the airbox design. There was a very deliberate restriction in the R1100S where the air intake wrapped around the rear of the airbox. Best guess is BMW wanted to increase air velocity leading into the filter. After all, exhaust gas is much greater in volume than intake.
     
  4. Rocky R

    Rocky R Active Member

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    A paper filter element may filter particles better, but a gauze filter such as a K&N definitely has less restriction/greater air flow.
     
  5. sxcR12RS

    sxcR12RS New Member

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    Indeed. Big but is the difference with better breathing will only be recognized north of 6k steady state which is too intermittent for me to make such a change. I'm w/ you in understanding however if you run your bike that hard...I feel shamefully slow in comparison (your flog > my flog). It's all good - the tweaks are human nature whatever we chose for them to be. /Steve
     
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  6. Allan "redfox"

    Allan "redfox" Active Member

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    I don't want to get into the "right or wrong" game here.
    But I only want to share my experience.
    Did some data logging with air pressures and airspeeds inside the airbox and intake pipe for a project long while ago (wanted to build a ram-air system onto my race bike) because I wanted to know what exactly happened inside.
    At the lower rev range the pressure drop at the engine side of the air filter compared to the acceleration of the air speed inside the intake pipe are quite a bit when you open the throttle. Stock versus open aftermarket air filter element. Engine reaction to this is noticeable and measurable.
     
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  7. RNINETRAT

    RNINETRAT New Member

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    I bought a BMC air filter for my Racer and if you look closely at the stock air filter and compare it to the BMC , you can see the difference. The stock air filter has a lot of paper media restriction.
     

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  8. sxcR12RS

    sxcR12RS New Member

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    I still think at lower rev's w/ modest horse power demand the difference between OEM and K&N air filter is negligible but stand corrected regarding effectiveness when one demands the horse power at any rpm not just steady state.

    BTW - absolutely no hint of lean running - the sound is everything expected from this gem of a motor and mileage is settled at 43mpg same as before the Cat removal - zero signs of hot-spots / bluing at this time. More practical use of the 2500-3000rpm range seems to be the biggest benefit to me and no, for 2-up the power is somewhat lacking still at the low end to what is desired but the bike is getting easier to ride 2-up from suspension preload/damping improvements made.

    Thanks for the discussion points raised regarding the air cleaner upgrade - this RS bike sure is a stable runner for me the way it is - not thinking of any further tweaks just piling on the miles.
     
  9. ray2

    ray2 Well-Known Member Contributor

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    (Just to keep it in perspective, we are all slow in comparison. You're new - check this out, if you haven't already stumbled across it.)
     
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