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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

    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
     
  9. krobi

    krobi

    Joined:
    Dec 31, 2010
    Where did you find those adaptors?( Found them) I have been reading all the related threads on this subject and can't wait to try this with mine. I already own the WEGO 3 2 channel and have contacted SC Delta about acquiring their system. I use this equipment for fine tuning carbs and all the info makes sense. My compliments to all the great investigation work from everyone involved. Thanks Kevin
     
    Last edited: Feb 2, 2020
  10. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    I got them from Innovate Motorsports. The part no. is 3835, and they cost $41 each.

    https://www.innovatemotorsports.com/

    Ken
     
  11. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    Not sure how accurate that o2 adapter is. In the car world those are used to cheat a check engine light when running without cats when a person doesn’t want to tune the ecu.
     
  12. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    A quick update on this effort is that I've collected a lot of data, and recently made my first cut at changing the fuel map. I had a problem with loading in a new fuel map. I never was able to get it to accept a new .cal fuel map file, so I had to change the map one cell at a time. The software does let me save the map to a .cal file after it is changed, but won't let me load it back in the ECU. I need to get back to SCS and sort out that issue, but just haven't got to it yet. I think it has something to do with the ECU being the original Norton item, but unlocked by SCS. When I was using their newer Delta 400 ECU, I didn't have that problem.

    The WEGO software will put the data in a table showing AFR in cells for throttle % vs rpm, which similar to the table in the SCS fuel map, making changes pretty simple. It will display the data in the cells as AFR or as percentage change from a desired AFR, the default 13.2 in my case. The changes I made were mostly in two areas, leaning it out in some of the low rpm, low throttle position cells, and adding some fuel in some of the higher rpm, mid throttle cells. I was conservative, and only changed about half of the calculated amount. I'm now in the process of doing enough riding, in varying speed and throttle positions, to collect enough data to make the next change. It's kind of slow, because normal riding doesn't get data for all the cells. You don't often see 8000 rpm at 5% throttle under load, or a sustained 1000 rpm at 100% throttle. The WEGO has to see a given cell condition long enough to know that it is a stable AFR reading before it will log the data point. A dyno would help for those conditions, but you would encounter them so rarely, that it doesn't really matter if they are off a good bit.

    The biggest change I have noticed so far is that I've got a lot less popping back in the exhaust on a closed throttle. I suspect it will disappear completely with the next changes. It also seems to take slightly longer for the idle to come up to speed (1100 rpm) after a cold start, probably because I did lean out some low speed, low throttle cells. It's not bad, but I can probably fix that later with changes to the cold start settings. Right now, I'm focused on getting it right for normal, full temperature conditions.

    More later.

    Ken
     
  13. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    I worried about that a bit, but the folks at Innovate said they are accurate, and they seem to be working properly for me. I do expect to eventually find a good way to add the 18 mm bungs and not have to use the adapters, just to clean up the appearance, even if for nothing else. And that will give me a chance to compare readings between the two configurations. I have noticed that the sensors take longer to come up to operating temperature with the adapters, compared to other bikes I've used the WEGO on with straight 18 mm bosses.

    Ken
     
  14. BritTwit

    BritTwit VIP MEMBER

    Joined:
    Aug 25, 2009
    Ken,

    Sounds like good progress.
    I'm considering sending my ECU back to SCS to get it unlocked, so would like to hear if they can help the .cal file issues.
     

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