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Need quiet exhaust, any ideas?

Discussion in 'Riding Gear and Bike Accessories/Parts' at netrider.net.au started by Jewfishy, Jun 1, 2015.

  1. Alright, so some copper pulled me over and told me my exhaust was too loud, I need to go and get it checked (some EPA place, got the paper work and will check later). Right now I have a VTR 250 with a staintune, pretty damn sure it doesn't meet the limit, but I bought a silencer for it anyway.

    Wondering if anyone has a spare stock exhaust for the VTR 250 or similar that I could grab, or know where I can get one. Doesn't need to be easily mounted, I can weld it on and take it off after if need be, just need a real quiet exhaust to pass the test before I swap it back over.

    Cheers.


     
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  2. Well the honda vtr250 is a full one peice exhaust.
    Your old muffled was cut off to fit the stain tune pipe mate!
     
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  3. Yeah I do realize that? I'm not a complete idiot?

    I bought this second hand, I don't have the old muffler. I was wondering if anyone had cut one off a VTR or similar bike and has one lying around that I could weld on to the pipe temporarily?
     
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  4. I get you now mate.
     
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  5. I had to do this for my car years ago and I made up a blocking plate out of tin that went in between the exhaust pipes after the cat. I drilled 3 holes in it and stuffed about 4 or 5 of those round balls of steel before the plate. Car lost prob half of its power but it was quiet as. Same principal should work for a bike. U might be able to just use the steel wool. Before u go there ring them up and ask them what noise limit is and how far away from exhaust the reading is taken from and get noise app on your phone so u can make sure it passes before the test.
     
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  6. Thanks alot mate, not too familiar with how an exhaust is laid out, but I assume that this is before the actual muffler itself? If it's actually inside the exhaust then I have a bit of an issue due to the fact I'd have to cut it open and weld it back up (there's no way to take apart a staintune exhaust, atleast my one anyway). Although, I can just make a removable plate on the exhaust if need be).
     
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  7. easier to make/buy an insert that will make it quiet.

    ones with closed end caps (stops direct exhaust pulse from escaping), longer non-perforated bit toward the end (increases the "buffer" effect) and small holes or slits near the closed end, will work best, like this:
    181553-db-killer-mod-imageuploadedbymotorcycle1366132645.602712.

    steel wool/baffle plates massively kill flow to cut noise, but the above type can still flow quite well, and the exhaust pulses cancel themselves out.. much better solution.
     
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  8. and to tune the sound to your liking, you can play around with the closed end, and have it half covered, like below with straps..
    make straps wider or thinner or longer, or change size of the reflecting bit right at the end, to tune the sound and volume. also, the length of closed pipe makes a big difference, 50-60mm or less is not much effect, 100-120mm long will have much larger effect.. the longer it is, the quieter.
    250 wouldn't need anything more than a 25mm internal diameter pipe to get full flow
    yes, it works..
    5576232740_851420a6d8.
     
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  9. What year is your bike?
     
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  10. 2003 VTR 250

    This seems like a pretty good idea depending on the price, I'll only stick them in on the day of the test anyway so it doesn't matter too much if it kills power, thanks for the suggestion though.
     
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  11. I've heard that in the DECC test that if it isn't stock you'll get faulted, everything on my bike is stock apart from the exhaust.

    If it meets the decibel requirements, will my bike pass the test, or will they fault me because it isn't stock?
     
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  14. Good Luck JewfishyJewfishy just for your information the testing procedure for NSW is detailed in

    National Stationary Exhaust Noise Test Procedures for In-Service Motor Vehicles

    It will be tested at revs determined by the Engine Speed at Maximum Power Or if they are lazy and don't know the maximum power/revs at 3000RPM.

    4.2.3.1 Where the ESMP for that engine has been determined by the testing authority
    the engine shall be brought to and stabilised at a speed as close as the testing
    officer can achieve to:
    (i) 1⁄2 ESMP in the case of a pre ADR83 motor cycle
    (ii) 1⁄2 ESMP in the case of any other motor cycle where the ESMP is
    more than 5000 rpm; or
    (iii) 3⁄4 ESMP in the case of any other vehicle.


    Maximum power in the VTR250 is at 10,500 RPM so it will be tested at around 5000 RPM.
     
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