2009 GS lean mixture, harmful???

Discussion in 'GS Boxers' started by carlesonra, Jan 7, 2013.

  1. roger 04 rt

    roger 04 rt Long timer

    Joined:
    Nov 9, 2011
    Oddometer:
    2,715
    Location:
    Massachusetts
    I'm interested in your comments on exhaust and intake lengths, thank you. Makes sense, though it seems like the realm for an expert. The R1150RT has shorter larger diameter tubes compared to the R1150GS which has longer narrower intake tubes.

    I saw the UKGSER stuff and there is a thread here too on someone who sent their ECU for remapping.

    My opinion is that most who use a power commander and get improvement do so mainly because the vast majority of tunes add fuel. My Wideband O2 project showed that if you add 4-8% more fuel by changing the lambda set-point you get good torque gains throughout the RPM range but especially good between 2000-3000 RPM.
    #21
  2. Marki_GSA

    Marki_GSA Long timer

    Joined:
    Sep 6, 2011
    Oddometer:
    1,454
    Location:
    Scotland
    Yes I agree it is mostly by adding fuel. The downside of the wide band route is that it doesn't really have much affect outside closed loop simply because the ecu doesn't look at them. Maybe not a problem for yourself and a lot of other riders especially on a big GS that isn't exactly a race bike. For some users though the retune is better if they are on the WOT a lot, generally driving hard. It's all preference and many will scoff saying it's not needed and a waste of time and money, others will see it as life saving and worth every penny/cent.
    #22
  3. roger 04 rt

    roger 04 rt Long timer

    Joined:
    Nov 9, 2011
    Oddometer:
    2,715
    Location:
    Massachusetts
    Actually when you richen the Closed Loop mixture with a wideband controller, it also adjusts the fuel in all Open Loop areas including WOT and Warm-Up through a process called adaptation. The 1150s and 1200s have that for sure and I suspect the 1100 does as well but haven't measured it yet. As an example if you set the wideband lambda to 0.94, WOT gets 6% richer and the warmup gets 6% richer after an adaptation period, I've measured the effect and presented recorded WOT and warmup AFR data.
    #23
  4. def

    def Ginger th wonder dog

    Joined:
    Feb 28, 2004
    Oddometer:
    13,599
    Location:
    The woods and mountains of Alabama
    Remember, reading plugs these days is different than from days of old when we had tetraethyl lead in our fuel. Also the old fuels were not blended with oxygenates. Also, many dirt bikes were 2 strokes...different animal altogether.

    As for megaphones, (reverse cone megaphones actually), cam overlap and Manx engines on old Brit bikes, they were dealing with completely different flows and had no EPA to deal with. Also Hailwood, Agostini and the boys were often limited to engines half the size of the current boxer displacement.

    Today, engines must comply. To do so, the state of tune is much milder, compression is lower, bore-stroke ratios are different, EGR is prevalent and we have engine fueling managed by computer, not the needle position, throttle valve cutaway and main jet size of the old Amal or Dellorto carburetors.

    Those days are gone unless you tear off the EFI and install carburetors.

    Aftermarket exhaust and fancy air filters do little more than lighten your wallet. If you want big performance, the boxer is not where it is at unless you're thinking turbo....

    To extract meaningful additional power from a boxer, you'll need major engine work. To improve driveability and engine manners, follow roger04rt's suggestions. His work is backed up with charts, AFRs and other sophisticated measurements that are meaningful.

    When you have spent north of $1000.00 on a fancy exhaust, your butt dyno is already biased towards at least 10 BHP gains before you even start the engine.

    Installation of fancy air filters carry slightly less butt dyno increases.

    Want a few free HP from your boxer? Change oil viscosity to 10w-30 or 5w-20. You gain several HP by reducing rheological losses.
    #24
  5. Marki_GSA

    Marki_GSA Long timer

    Joined:
    Sep 6, 2011
    Oddometer:
    1,454
    Location:
    Scotland
    Mmm turbo :thumbup: but no your right. If you want 180bhp go buy a K1600
    #25
  6. Disco Dean

    Disco Dean Long timer

    Joined:
    Jul 17, 2007
    Oddometer:
    1,387
    Location:
    The Great White North
    I agree totally, this is really great to understand but it has all been gone over before in much more detail by much smarter blokes than me.

    What I am saying I guess in a very verbose way is that the addition of an aftermarket air filter or pipe will retune a bike (for sure) but the bike ECU will retune it back and will change the mixture of the bike back to the prescribed parameters - as that is what the bike is constantly trying to do based on load, throttle, and sensors. Now if the bike is capable or not... I think so - some think not.

    Everything that we have been talking about has been covered in minute detail here.

    And if you are interested in the ECU reprogram (which will give you huge HP gains and other changes and combined with an exhaust and filter...) info can be found here.

    One must either trick the bike or change the mapping. At least thats what I believe. And I am done here... no more room in my brain for anything but this.
    #26
  7. roger 04 rt

    roger 04 rt Long timer

    Joined:
    Nov 9, 2011
    Oddometer:
    2,715
    Location:
    Massachusetts
    On this point, you're right and I've measured it. In the R1150 and R1200 documentation, there is clearly description of the Adaptation Values that would allow the fueling to get back to the settings of the Lambda sensor after an Adaptation period.
    #27
  8. def

    def Ginger th wonder dog

    Joined:
    Feb 28, 2004
    Oddometer:
    13,599
    Location:
    The woods and mountains of Alabama
    Nothing sounds like a big Matchless, AJS or BSA single on the pipe. I get weak in the knees when I hear one (which these days is rare).

    My Triumphs and BSAs used to spray fuel on my legs at idle from cam overlap but, my B'ville T120 would spin up to just short of 10,000RPM on pump fuel with a lightened rotating assembly, T&M 6 and 9 grind cams and aftermarket compound wound valve springs. Those were the days.
    #28
  9. def

    def Ginger th wonder dog

    Joined:
    Feb 28, 2004
    Oddometer:
    13,599
    Location:
    The woods and mountains of Alabama
    Now yer talkin'.

    But, that is an ugly bike too however, the power is impressive.
    #29
  10. Disco Dean

    Disco Dean Long timer

    Joined:
    Jul 17, 2007
    Oddometer:
    1,387
    Location:
    The Great White North
    Sigh... yes I know. Nothing quite like it. No amount of sound tuning by computer will ever get that wonderful sound of a big british single.... Goldstar, Manx.... Commando(twin)...or my nice little Ducati 250 with an open megaphone. Yummy to say the least if that is an appropriate word for it.

    I was recently at the Vintage festival in Hockenhiem and they warmed up a Honda 6. I don't care what anyone says that is one of the magical wonders of the world - someone figured it out and someone made it happen. Magic.

    Now if I can just read the fault code or write some new programming for my GS.... There is no virtual reality in a Honda 6.

    Yes "Def" Those were the days.
    #30