Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Exhaust Core Size?????? quick help please

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by slickncghia, Jul 14, 2008.

  1. G'day Guys



    Since the canary i need to fix my exhaust. Once i opened it up it was a real mess in there.

    Long story short im planning on getting some new perferated core to replace the rooted stuff insite and re-welding the end piece to the core.

    Its a Big Single. Suzuki Dr 800 to be exact.

    The mufler needs to be quiet enough to pass a noise test by Vicroads but i dont want it to restrict the horses.

    I am thinking 1 3/4" core is about right?

    anyone with a single or knowlege about zorsts would be really handy. need to get it sorted ASAP

    Cheers
    Ben
     
     Top
  2. anyone? its a 2" midpipe. but 2" might be over kill for the bike and just addind noise
     
     Top
  3. just make up a noise tube. Solid piece that bolts to the can's exit area that travels into the can by about 3" that should do enough so it passes the test.
    Then when you are at home, unscrew it and you are back to normal.


    Or Ring Ken at Megacycle and get him to rebuild it for you.

    He charged me $50 for a perforated inner tube for each yoshi.

    Easy
     
     Top
  4. just spoke to matt there. he said theyre normally around 1 3/4". however he didnt think they would be able to expand it to 2" as the core is pretty brittle.
     
     Top
  5. ok ive ordered some 1 3/4" from a car zorst place as they were cheap and helpfull. they reckon they can make it fit as the inlet pipe is 2" outside diametrer. might also see if they can weld up the connection to the end cap.
     
     Top
  6. Get some of this stuff. it is 2mm perforated steel. It is easy to hand roll, and is great for making the guts of a muffler. use insulwool or similar, for the sound deadening material. Cheap to do. easy too.
    Pq16Pgp9.
     
     Top
  7. it ended up coming down to 1 5/8" or 2". i went the 1 5/8" because it should be quieter and i have to pass the test.

    and it really should still be a big enough core for the ammount of air this thing should be pushing out. if i find later that its restrictive i can always try a 2". hopefull ill have it back from the exhaust guys on mon or tues.

    by the way. this is the "performance core" that was in it already
    th_can1.
    th_can2.
    [​IMG]

    and this is what im invisioning

    th_cancut.
     
     Top
  8. If the airbox has been opened up then a 2" core pretty good for expelling the amount of gas a big single puts out otherwise 1.5" is sufficient. Biggest thing I've found with my motard and noise was to make sure the exhaust was well packed because as soon as the packing started to let go the noise increased quite substantially and there wasn't a chance of passing any noise test.

    As someone mentioned at the start, just stick a smaller baffle into the end of a 2" pipe, secure with a self tapper and remove when its passed the test. Even the 1 5/8" might have problems with the noise test depending on how long the silencer is....
     
     Top