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Thread: Rich vs Lean (Mixture Adjusting)

  1. #1
    papafoxtrot
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    Rich vs Lean (Mixture Adjusting)

    Hi Folks,

    I know my 07' R12R is running quite lean. The headers have blued in 5K mi. and she pops thru the exhaust on deceleration. I would think with a closed loop FI system this would not be the case, but - is there any tweek I can make to richen things up a bit? Is there a special tool required? I've got a copy of the BMW CD manual for the bike and can't (yet) find any tuning information in it. What's a boy to do?

  2. #2
    riding the bike(s) grasslander's Avatar
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    Quote Originally Posted by papafoxtrot View Post
    Hi Folks,

    I know my 07' R12R is running quite lean. The headers have blued in 5K mi. and she pops thru the exhaust on deceleration. I would think with a closed loop FI system this would not be the case, but - is there any tweek I can make to richen things up a bit? Is there a special tool required? I've got a copy of the BMW CD manual for the bike and can't (yet) find any tuning information in it. What's a boy to do?
    Slight popping on deceleration and pipe going blue is common on the Hex.

    Nothing short of a Techlusion or RapidbikeIII module to piggyback the ECU will probably effect a FI "tuning" change. When we did dyno runs of the stock r1200st , we found the map stock to be quite good and very near stoic. Maybe a touch lean below 4000rpm. If you want to fatten below 4200 RPM you will probably have to eliminate the O2 sensor and remap using a module (closed loop below 4200 so the O2 sensor looks to control the map).

    Have your dealer check it out if you believe you have a problem. Really, the motor and fueling is one area of the power train where BMW got it pretty right.
    Jim Doyle
    Expert M/C road racer and crew chief, owner G-Baby Racing endurance team
    2013 ASRA/AMA Team Challenge GTL National Champions
    2015 US National Endurance Series LW National Champions

  3. #3
    papafoxtrot
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    Quote Originally Posted by grasslander View Post
    Slight popping on deceleration and pipe going blue is common on the Hex.
    Something being common doesn't make it right. I'm not trying to be argumentive. Blue pipes have always been a sign of running hot/lean. I understanding having to meet emmissions reg's but running real lean, especially in a non-water cooled engine can't be good.

    Nothing short of a Techlusion or RapidbikeIII module to piggyback the ECU will probably effect a FI "tuning" change. When we did dyno runs of the stock r1200st , we found the map stock to be quite good and very near stoic. Maybe a touch lean below 4000rpm. If you want to fatten below 4200 RPM you will probably have to eliminate the O2 sensor and remap using a module (closed loop below 4200 so the O2 sensor looks to control the map).
    I did a search on the two units you mentioned. I like the info on the Techlusion unit even though I've gotten mixed information on if they have one for the R12R. Have you (or anyone else) any direct experience with either or both units and/or a recommendation?

    Have your dealer check it out if you believe you have a problem. Really, the motor and fueling is one area of the power train where BMW got it pretty right.
    I do appreciate your input.

  4. #4
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    You bring up an interesting point. Exhaust temperature will peak with a stoichiometric mixture. Running more lean or rich will bring the temperature down. Running too lean is good if you're trying to minimize emissions, but bad if you're interested in maximizing power and engine life. I suspect some concessions have been made to the EPA.

  5. #5
    riding the bike(s) grasslander's Avatar
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    Quote Originally Posted by papafoxtrot View Post
    I did a search on the two units you mentioned. I like the info on the Techlusion unit even though I've gotten mixed information on if they have one for the R12R. Have you (or anyone else) any direct experience with either or both units and/or a recommendation?
    From a thread reply from at another site. This should all apply to 1200GS, RT, ST and your R. Maybe this info will help you a bit with your search.
    Ok been doing a little surf'in and emailing. Here is what I know about chips for hex heads so far:

    DYNOJET Power Commander: $430-500.00 + dyno time
    Supported models have maps available reducing dyno time
    Great tune-ability for lean and rich by RPM and throttle position.

    "There are no plans to develop a unit for the R1200's at this time. We are actually not able to do anything for BMW's with dual O2 sensors at this time as the Wide band PC will only accommodate feedback from one sensor. Should anything change, we will post any updates on the site, but there are no plans to develop this any time soon."

    I appreciate DynoJet's candor but, I would say this means this product is not an option anytime soon...

    WUNDERLICH Power Controller: $349.00 + dyno time for fine tune
    DOBECK Performance FI-1333ST Gen III: $349.00 + dyno time for fine tune if you want. (this unit is used to tuned like a carb see their documentation. Supose to not require dyno time)
    Essentially the same unit. The unit adds fuel on to the existing map can't reduce fuel. I'm not sure that's a huge deal in my situation since I was pretty much lean to a degree everywhere (see below link for dyno charts and fuel map info). When I asked Dobeck about O2 sensor use they gratuitously responded with this information:

    "The BMW GenIII device reads and adjusts fuel for each cylinder individually - in closed loop operation. The open loop fuel adds, yellow and red, are common to both cyls."

    Sounds like you add you fuel to the curve and the O2 sensors do their normal stuff.

    DIMSORT Rapidbike 3 (from evoluzione) $470.00 + dyno time for fine tune
    Full kit with rapidbike3 box, harness, software & cable
    "if your tuner is used to power commander software, he will really like this kit"

    * You can use the o2 sensors but we usually just eliminate then and map accordingly.
    * The O2 sensors work just like the factory setup.
    * You can add or subtract fuel throughout the entire range. you can also add/subtract timing advance.
    * The unit will come loaded with a base map for the r1200rt/st motor.
    * We usually disconnect the o2 sensors because the transition from closed loop to open loop is difficult to make seamless.
    * There is no need for the o2 eliminators (though the o2 sensors can be connected back at any time). (say an emissions test - my note)

    Added bonus. This unit can carry 2 maps and be changed with a the flip of a switch! (you know, core in - core out)
    Added bonus. Buy a new bike, re-flash and new cable loom for about $60

    *** All systems piggy back the ECU - disconnect, back to stock map. Reconnect back to performance settings.

    Constructive comments? Concerns?

    Dyno charts for reference here:
    http://bmwsporttouring.com/ubbthreads/sh...&PHPSESSID=
    All pricing is estimated and this is from March of 2007 info so buyer beware. (For reference, I've never added this stuff and run with a full Remus using the stock map.)
    Jim Doyle
    Expert M/C road racer and crew chief, owner G-Baby Racing endurance team
    2013 ASRA/AMA Team Challenge GTL National Champions
    2015 US National Endurance Series LW National Champions

  6. #6
    Registered User ANDYVH's Avatar
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    Blued header pipes are common on all the Oilheads and Hexheads. The exhaust popping on decel is characteristic as well, and indicates the lean condition of off-trottle decel, which is done mostly to limit decel emissions peaks.

    I installed a Techlusion on my 94 RS and it richened up the mix just enough to fill in the bottom of the power curve and all but eliminate the popping out the exhaust on decel. I have a heavily modified stock muffler which popped even more on decel until I installed the Techlusion. I'm very happy with the results, but it does take some careful methodical tuning steps. Matt at Dobeck/Techlusion rides a Oilhead and he was a great help.
    Get trained! The best "performance" upgrade you can get is YOU. Visit msf-usa.org for training info.

  7. #7
    papafoxtrot
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    Well, I bit the bullet and ordered one of the Dobeck units over the weekend. It was the FI-1333ST Gen III unit grasslander refered to. The price was down to $249.00 with free shipping. I'll add to this thread on my impressions on both installation and subjective performance results. It should be easy to tell if she stops backfiring on decel, the rest may be a bit more difficult to get objective results. Don't know who has a dyno around here anymore. The one place I used to deal with has closed up shop.

  8. #8
    Registered User ANDYVH's Avatar
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    You won't need a dyno, cause your "seat o' the pants" dyno will tell you the bike is running like it should have all along were it not for the emission standards the manufacturers have to adhere to. It should be pretty obvious once you have it dialed in to the settings Dobeck recommends.
    Get trained! The best "performance" upgrade you can get is YOU. Visit msf-usa.org for training info.

  9. #9
    papafoxtrot
    Guest
    Quote Originally Posted by Andy VH View Post
    You won't need a dyno, cause your "seat o' the pants" dyno will tell you the bike is running like it should have all along were it not for the emission standards the manufacturers have to adhere to. It should be pretty obvious once you have it dialed in to the settings Dobeck recommends.
    First Impressions:
    I installed the Techlusion unit yesterday(12/15). The whole process was pretty straight forward. The manual says the install will take about an hour, and that's just what it took. It might have been easier/faster if they gave more info about routing the wires. That took about 90% of the install time.

    After routing the wires, what you have, is two sets of connectors for each cylinder. You disconnect the injector and the O2 sensor and patch the Tech units wiring in between. The bike fired right back up as if nothing had happened but immediately settled into a much smoother idle. Blipping the throttle was much more responsive too. And best of all, when I tok the bike for a test ride, there was no popping or spitting on closed throttle deceleration. I'm very impressed and I haven't moved anything from the initial settings installed in the Techlusion unit!

    It's pouring like crazy today so the tweaking (if any) will have to wait for better weather. I positioned the control box under the seat near the tail light. There was a flat area there on the sub fender and the small brain unit fit perfectly. Tweaking seems a bit complicated yet. I'll have to do more reading, but if you're interested in improving the ride-ability of your bike, this was a cheap and effective upgrade.

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