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  1. #1
    Gold Member mik's Avatar
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    Default muffler mods

    I purchased a muffler from an R and I plan to slice it open.

    I also want to modify, through software, the operation of the exhaust muffler servo.

    Apparantly the valve opens at idle and low rpm, closes midrange and opens back up in high rpm for better flow. After I modify my muffler, the 'open' condition will be significantly louder so I'd like to keep it closed at low rpms.

    I found a helpful link

    http://badweatherbikers.com/buell/me...tml?1228060924

    and in it I found a sub-link

    http://www.badweatherbikers.com/buel...38/375761.html

    and of course

    http://www.ecmspy.com/eeprom_info.shtml


    sekalilgai on bwb
    "Region 1 is defined by the values in 0x208 and 0x209. Region 2 is defined by the values in 0x20A and 0X20B and finally region 3 is defined in 0x20C and 0X20D. So each address give you one 8bit value that translates to RPM (by multiplying by 50). That is how the 'table' is stored. It is more like an array of six, byte-wide values than ...say an Excel-looking table. Sorry for the misunderstanding. Take another look at the ECMSPY page, it'll make sense."
    Last edited by mik; 02-06-2014 at 05:17 PM.

  2. #2
    Wonders How Big It Is piratius's Avatar
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    Ok. what I took from that is that there are three values, and the data ranges determine the RPM's that the valve opens/closes at.

    Region 1 (open, idle/low) is 0x208 & 0x209
    Region 2 (closed, midrange) is 0x20A & 0X20B
    Region 3 (open, WOT/high) is 0x20C & 0x20D

    You take the desired RPM (Let's assume 1000rpm for right now as an example) and divide by 50. 1000 / 50 = 20. HOWEVER, THIS IS STILL IN DECIMAL NOTATION! YOU NEED TO CONVERT THE VALUE TO HEX!! 20 notated in Hex is actually "14" - you probably don't need to get down to the nitty gritty now, there are free conversion tools online, like found here: http://www.rapidtables.com/convert/n...mal-to-hex.htm

    So, to change the table, you need to set Region 1 to be very small (and low in the RPM range), Region 2 to be very broad (from idle until it's normal place), and leave Region 3 alone (for starters).

    The cells located at 0x208, 209, 20A, 20B, 20C, and 20D should all be adjacent. I would do the following:

    FIRST - back up your file!
    SECOND - write down the values from 208 through 20D that you're going to be changing!
    Then, in ECMSpy...Load the EEPROM, then navigate to the tab that says "EEPROM". Scroll down to row 200, and then find column 08.

    Set 0x208 to "01" (Muffler valve opens when the engine is at least 50rpm)
    Set 0x209 to "02" (Muffler valve still open when the RPM reaches 100rpm)
    Set 0x20A to "0A" (Muffler valve closes at 500rpm)
    Set 0x20B to "0B" (Muffler valve still closed at 550rpm)
    Leave 0x20C alone (Muffler Valve reopens at 5000rpm)
    Leave 0x20D alone (Muffler Valve stays open at 5050rpm)

    -Brad

    EDIT: Pictures!
    Stock EEPROM:

    EEPROM Cells highlighted that control the muffler valve:

    EEPROM Cells edited to have the muffler valve closed from idle to 5000rpms:
    Last edited by piratius; 02-07-2014 at 01:41 AM.

  3. #3
    Gold Member mik's Avatar
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    That's about what I got out of it too.

  4. #4

  5. #5
    Gold Member mik's Avatar
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    been doing some thinking and more browsing and planning.

    I'm kinda liking a little something like this....

    http://www.badweatherbikers.com/cgib...77&page=605711

    http://www.buellxb.com/Buell-XB-Foru...t-exit-exhaust



    The second one just has nice diagrams to reference. Basically, instead of having a triple pass stock muffler, making it into a dual pass muffler with no rear exit at all. Remove the rear cap, cut out the stock tailpipe, add a U-bend between the two top pipes, make a hole in front of the muffler valve in the front chamber, put back together.

    For ease of fabrication I wouldn't take it apart completely and add all new internal piping, nor remove that third pipe at the bottom, I'd just leave it as somewhat of a balance tube between the front most and rear most chambers. One of the two top pipes has some holes in it that basically let it use the middle chamber of the muffler as a resonance chamber to break up the pulses a bit. I've heard rumors that there is batting or something inside the middle chamber, but have yet to find pictures as evidence.

    Now for the front exit pipe, I had planned on making it not like just a vent hole like these others, but more like a pipe that almost connects to the internal valve in the muffler. That way when the valve is open it just shoots straight out. However, I would also drill many holes around the pipe so the exhaust that has made the full path through the u-bend and dumped into the front chamber gets the pulse broken up and has to get through the holes to exit the muffler. I certainly would make sure the cross sectional area of those small holes added up is greater than the cross sectional area of the internal tubes, but not by a ton as I do want it to be a little restrictive/muffling for when the valve is closed and I want it quieter.


    Now I just need to cut it opened and find a 2-3/8" radius, 1-5/8" u-bend on the cheap.


    Goals:
    Reasonably simple to fabricate
    Smooth flow, but reasonably quiet when valve is closed and going through the 'full' two passes of the muffler
    free flowing when the valve is opened (yes it'll be quite loud), and I'll be modifying the ECM to have the valve only opened above 4000-4500 rpms.


    edit:
    piping
    1-5/8", 2.44" radius.... might be close enough http://www.summitracing.com/parts/sum-621002/overview/

    edit: http://www.buellxb.com/Buell-XB-Foru...-exit-exhausts
    Last edited by mik; 06-03-2014 at 09:47 PM.

  6. #6

  7. #7
    Gold Member mik's Avatar
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    Quote Originally Posted by ezblast View Post
    Drummer.
    EZ
    Thanks for trying, but a drummer exhaust clearly does not fall into the lines of everything I have talked about in my posts for goals.
    Last edited by mik; 06-03-2014 at 10:13 PM.

  8. #8
    Super Moderator ezblast's Avatar
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    Best all around exhaust you can get, after that the Keda - doing mods on an a stock exhaust - if you don't know what your doing will just depress the heck out of you.
    EZ

  9. #9
    Gold Member mik's Avatar
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    There's the good ole positive, motivational spirit that gets people to reach outside the box and try new things. You're supposed to be a leader and innovator, but me thinks you're stuck in the mindset that everything has been done and thus you have all the answers. I'm interested in tech, theories and first hand experience, not canned responses on ways to spend money. My friend (levi) and I did major surgery to an 1125R muffler with specific design goals. We achieved exactly what we wanted in a dual mode muffler. Have some faith in peoples' ingenuity.

  10. #10
    Super Moderator ezblast's Avatar
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    No, not true - if you want to go there, you'll have to hook up a portable unit like Lee does with his phone. I was teasing you about the other exhausts though they are not hard to copy - the plans are out there on the net. A nice Force exhaust with the welds redone would be ideal - lol - but your just working the can - then why not a turbulator style - exhaust - I myself would ditch the stock exhaust in the search for power, because loosing all that weight will add a couple of horses by itself. The Turbulator idea was actually thought to be pretty sharp idea by the badweb engineering group. Playing with the stock one though may be a good mind exercise - and you could probably get a few more ponies out of it. That whole valve thing is a hi tech version of what chopper riders did long ago though.
    EZ

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