How do you shorten an exhaust? Can it cause issues?

Discussion in 'Mods, Upgrades, Accessories and Products' started by martinowen, Jan 22, 2013.

  1. martinowen

    martinowen Moderator
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  2. phantom

    phantom Active Member

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  3. arthurbikemad

    arthurbikemad A very helpful Gent

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    Think they were also know as mad doctor tails.
     
  4. phantom

    phantom Active Member

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    yup the same ones...so you remember from all them years ago lol
     
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  5. sinewave

    sinewave God Like

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    I always feel that those single Zorts which protrude past the tail piece make the bike look like a Dog with Haemorrhoids squeezin' a shyte out by a lamp post! :eek:


    ........... or even worse a 'Taker' up Canal Street! :eek:



    ............................ or is that just me? :rolleyes:
     
  6. arthurbikemad

    arthurbikemad A very helpful Gent

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    Or the cats bum! :) It's where it should be IMO, balanced in the middle....not stuck out the side dragging in the wind...lol that's why RR7s are so fast, less wind drag.. ;)
     
  7. phantom

    phantom Active Member

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    I prefer the underseat set up too, thats why I had to sell that yoshi.
    it poked out the side like an after thought.
     
  8. Freedom of choice

    Freedom of choice Elite Member

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    I was wondering why are you running a Dublin plate when you live in the Noorf ?
     
  9. phantom

    phantom Active Member

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    and on a repsol instead of a mightly HRC :p
     
  10. JM1

    JM1 Active Member

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    Theoretically, i think this could slightly reduce low/mid range power, although could maybe be recovered by fuel mapping update.
    In reality, you probably won't notice any change.

    P.S. Hoping an expert can come and confirm/deny.
     
    #30 JM1, Jan 23, 2013
    Last edited: Jan 23, 2013
  11. martinowen

    martinowen Moderator
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    Phantom would you mind photoshopping this pic for me when you aren't busy?:) If you wouldn't mind doing it at 2 lengths just to be more cheeky :D
    One so ends at the tip of the rear and one so it finishes at the start of the rear light if that makes sense.
    I have it ago my self but it wasn't very good!

    [​IMG]

    [​IMG]

    [​IMG]
     
  12. kpone

    kpone Moderator
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    A bit rough and rushed Martin, but,

    short pipe 1.jpg

    short pipe 2.jpg
     
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  13. martinowen

    martinowen Moderator
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    Cheers ken that's almost as good as mine, I think I like the shortest one but not sure how much effect this may have
     
  14. phantom

    phantom Active Member

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    just seen your post so threw
    these together...right off to work ;)

    short

    short.jpg

    shorter

    shorter.jpg
     
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  15. kpone

    kpone Moderator
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    Not so much that as, oddly, even with Photoshop I had to cut away a lot of the undertray to make it fit. The shortest version is missing about a third of the can.
     
  16. martinowen

    martinowen Moderator
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    I wonder if I can get it to sit as hi as that as it looks great like that!
     
  17. arthurbikemad

    arthurbikemad A very helpful Gent

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    Agree any changes to the system will have an effect somewhere across the rev range, normally speaking shortening an exhaust will increase top end with a loss of some bottom or mid, but like you say you could only be talking one or two bhp in this case, it can nearly always be mapped out but tbh the graphs will always show the changes in most cases even if small, saying that looking for such a small change like here would be hard. Id fully agree that with the state of tune and the amount that's wanted to be removed no change would be noticed....other than it may be a little louder :D
     
  18. kpone

    kpone Moderator
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    Even if you can make it fit without buggering up the performance, you'd need asbestos balls.

    A friend of mine, a shortarse, shaved an inch off the foam on the saddle of his Firebolt. After about 5 miles he had to jump off it, the muppet.
     
  19. martinowen

    martinowen Moderator
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    Looking at the shorter pic on phantoms, if it would sit like this I would prob have the exhaust end at the light but the tip going past, if I can get it to sit like the short one in ken's pic I will cos its perfect :D
     
  20. Haggler ®™

    Haggler ®™ Active Member

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    If you shorten it too much it,ll melt your rear lens and if it's a clear one it,ll make it go brown..I fitted my Akro the other month and although it sounded great I just could not live with the fact it stuck out massive from the rear edge of the seat unit.A couple of hours later and it now sits about 20mm longer..........I trimed off 50mm all told,it's a tad louder but I can live with that...........as for performance?......dont know yet as I hav,nt got to my mates to get him to Dyno it.
     

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