MAC 2 into 1 exhaust questions

Discussion in 'Airheads' started by R90pilot, Mar 10, 2012.

  1. R90pilot

    R90pilot Adventurer

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    My R90 needs an exhaust and I was wondering how the Mac 2 into 1 system sounds. With and with out baffels. How did they fit? And did you need to jet the carbs different?

    So if anyone has any info on these i would really appreciate your feedback

    Tom
    #1
  2. bereahorn

    bereahorn Long timer

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    Good questions. I have a kit still in the box that I haven't installed on my 90/6. :ear
    #2
  3. DoktorT

    DoktorT BigBrowedNeandereer

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    Used one years ago on my 90/6. Sound was louder/deeper but not offensive. It did not have removeable baffels. Adjustment for mixture was very small if at all with stock jets. Certainly within stock range of adjustment. MPG was unchanged, still excellent. No seat of the pants difference in power.

    I bought it for less weight and cost over stock.
    #3
  4. craydds

    craydds Long timer

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    Had a set on my old R90/6. Sounds great with baffles - not too loud (loud pipes save lives). Never ran it with baffles removed. Good fit, easy to install and remove. No need to re-jet (Bings) although with your bike at your elevation it might be an option. I think I still have the Mac's out in the barn - might be a bit beat up. Let me know if you want 'em.
    #4
  5. R90pilot

    R90pilot Adventurer

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    Goood to know guys, I am mid restore of mine and I was thinking they may be a nice addition to the restore while still saving some money over new. I do not want it to be too loud but I do enjoy the sound of a nice motor.

    CrayDDS,
    How beat up are yours? I amy be interested in them if I can make them look good.

    Thanks
    Tom
    #5
  6. dlrides

    dlrides 1:1.618

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    Good sound minimal adjustment if any :



    [​IMG]
    #6
  7. craydds

    craydds Long timer

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    Tom, I might get up to my barn next weekend (it's 250 miles away, on my folks farm). I think they have a few dings, I'll make some pic's. If they're not too fugly, I'll send 'em to you.
    #7
  8. gsd4me

    gsd4me 90% bluff

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    I had a two into one on an R100S many years ago, it looked and sounded great, but the pipes had to be removed to change the oil filter; not good in my book. That would be one thing to look out for.
    #8
  9. Boxer Metal

    Boxer Metal Mad Scientist

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    They are a 5-7 horsepower robber.
    #9
  10. wirewrkr

    wirewrkr the thread-killer

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    EggZackly True.
    #10
  11. supershaft

    supershaft because I can

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    Man. 5 to 7 hp on most of these bikes is around a 10 to 15% reduction in peak power. Very noticeable yet the people with experience with the pipes on this thread didn't notice it? Of course, they didn't notice any such gains in lower rpms either. Typically, two into ones just like crossovers cost a bit of power on top for a bit more power somewhere else. In my experience with Luftmeister two into ones, the trade off isn't nearly so grand. From the looks of all the airhead race bikes I see running two into ones, a lot of people like the tradeoff as far as getting around tracks the fastest is concerned. Of course, some opt for more top end. It all depends on your priorities.
    #11
  12. Boxer Metal

    Boxer Metal Mad Scientist

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    #12
  13. dlrides

    dlrides 1:1.618

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    Depends on the type of oil, bars, seat, and maintenance spreadsheet.


    :wink:
    #13
  14. R90pilot

    R90pilot Adventurer

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    Got my exhaust today and I am not very happy with the first fit. One side will rub the center stand and the rear brake lever also hits the side. My brake lever is somewhat tweaked from the PO dropping it so maybe that will help. Wish now I would have spent the extra money and went with stock
    #14
  15. bmwrench

    bmwrench Long timer

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    While I have given up on MAC, a new stock system will set you back $1236.51 at MSRP. Stunning.
    #15
  16. Hawk Medicine

    Hawk Medicine Coyote's Brother

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    Yep!

    As the next few years unfold a lot of guys are going to be priced out of the chance to ride Airheads.

    Kinda sad really...
    #16
  17. supershaft

    supershaft because I can

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    IMO Mac's have always been just a cheap, bad copy of the Luftmeister two into one. Those were good exhausts.
    #17
  18. R90pilot

    R90pilot Adventurer

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    I worked on the fitting of it last night and it seems to be ok now and not rubbing anything. My brake lever was the main issue and I tweaked it back to normal however it feels as if the mounting is somewhat soft and may bend again. I also am concerned if my rear storage cases will clear the bigger pipe
    #18