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AFR Monitoring Adventure

Discussion in 'Norton Motorcycles (Modern)' started by lcrken, Apr 23, 2019.

  1. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    I've just finished installing a WEGO air/fuel ratio monitoring system on my 961, and had my first ride with it functioning. As I've mentioned in other threads here, I'm at the moment using the original SCS ECU, but unlocked by SCS so I can change settings and maps as I choose. It currently has the 077 map ( for Commando with race exhausts) installed, South Bay silencers, and I have removed the cats, narrowband O2 sensors, and idle air control system, blocked the air passage between the injectors, and have disabled the idle control function in the ECU. At this point the bike idles and runs great, but I'm still curious to see how the mixture looks under different riding conditions.

    I had originally planned to fit bungs to the decat pipes for the larger 18 mm wideband sensors, but had some clearance issues doing so. Instead, I'm using a pair of angled 18 mm to 12 mm adapters in the original sensor fittings. I was worried about them working with the extra distance between sensor and exhaust gas, but they seem to work just fine. That at least leaves me the option of re-installing the original narrow band sensors, although I really doubt I'll ever have reason to do so.

    This is a shot of the wide band sensors installed.

    Lambda Sensors Side 1200.jpg
    And this shows the display zip tied to the bars. It shows the numerical AFR for both left and right cylinders. You can also see some of the extra wiring tied out of the way for now. I can use those later to add rpm and throttle position to the data logging, as well as the USB connection to download the logged data.

    Display 1200.jpg
    And this shows the wiring from the side. The large coil of wire hanging off the headlight bracket is because I bought the system with automobile length leads installed, so I can use it in a blown Studebaker project I'm doing with my grandson.

    Wiring Left View 1 1200.jpg

    So, what sort of results so far? Not a lot, just one short ride. Items of interest I did note are that the two cylinders read almost identical AFRs all the time. At most, they will differ by 0.1, and only temporarily. Also, the AFR at wide open throttle under load seems about right, staying pretty close to 12.5, and steady cruising at most throttle settings is between 13 and 14, where it should be. I did notice that it is quite rich at idle and om low speed, closed throttle, cruising. Usually around 11.5. Under part throttle acceleration it stays between 13 and 14, with an occasional transition reading as the throttle is first cracked open that gets a bit lean, 15 or 16 max. The other interesting feature is getting to watch the fuel flow shutoff for closed throttle deceleration above the cutoff rpm for that function. The AFR reading just goes to it's max of 19.5, or goes out of cal until the rpms drop or the throttle is opened. That's it for now. Next step is to hook up some more connections so I can do some serious data logging.

    After playing with the orginal ECU a bit, I'll be swapping in the D400 ECU to see what I can do with it.

    Ken
     
  2. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    That’s very interesting Ken, thanks for posting.

    Also very interesting to see that, all in all, the set up seems to work well with regards to AFR.

    My layman’s thinking is making me wonder that given how the AFR seems so good, if / what improvements can we expect to see with the ECU changes ?
     
  3. ntst8

    ntst8 VIP MEMBER

    Joined:
    Feb 14, 2004
    Off topic but compliments on the offset mounts for the mirrors.
     
  4. richard-7

    richard-7

    Joined:
    Feb 24, 2014

    Great info. Thank you for sharing.
    Richard
     
  5. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    I look forward to your future reports . Thanks for your feedback .
     
  6. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Thanks. A simpler solution would have been to look for some mirrors with longer stems, but I already had these mirrors and liked their looks, so making the offset mounts seemed a reasonable solution. They give me a much better view to the rear than before.

    Ken
     
  7. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    You sure the real reason wasn't that you’ve got a mill... and found an excuse to do some milling...?
     
  8. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Well, there is always that:).

    Ken
     

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