wideband tuning, rear or frt cylinder??

Discussion in 'Engine, Fuel and Exhaust' started by 87gtNOS, Apr 14, 2012.

  1. 87gtNOS

    87gtNOS Member

    11
    0
    0
    Hello, I am moving my LM1 Wideband from my Vette to the bike.

    I am thinking I need to put the O2 into the rear cylinder, as it likely runs hotter?

    Thanks
     
  2. 87gtNOS

    87gtNOS Member

    11
    0
    0
    wow, no one has tuned with a wideband....I'll be the first!!
     
  3. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

    4,034
    68
    42
    With my Dobeck Gen 4 they chose that I should tune by the front cylinder.
     
  4. Hoople

    Hoople Account Removed

    7,198
    0
    34
    Interesting thread that I am sure raised attention in many including myself but you didn't say what you wanted to accomplish and how you were going to do it. Were you planing to use the Innovate tail pipe adpater or are you going to install the LN1 where the narrow band is now and force open loop within the entire A/F map? Your going to use a SEST and change the VE tables or force overide using a piggy?
    No info usually = no interest. :)
     
  5. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    Hotter yes due to less air flow, but not leaner persay.

    That is correct, although that might be since it's nearer to the handlebars where the gauge is mounted. " IF " the OP's tuner is manually adjusted to meter read data (as is the GEN 4 as I understand it) then he might would consider the front for the same reason.

    Or does the OP's tuner have some sort of flash hoop cable that is compatible with his bike's ECM so he can look at recordings and/or reflash target values ?

    I could have never worded such specifics but thanks to Hoople, yes ditto on the above. And also is the OP's bike equipted with a CAT, since I read Innovate adaptor works only on "NON" cat'd implemetations.
     
  6. 87gtNOS

    87gtNOS Member

    11
    0
    0
    I have already unplugged the stock 02's using the TFI.
    If you tune on the colder 'front' cylinder, and dial it in, it only makes sense that the 'hotter' rear cylinder could use some more fuel to cool it.

    BTW, I would be tuning with Lambda, not A/F Ratio....
     
  7. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    Tis true that an ability to alter the ratio of the rear "only" would cool it down somewhat. It presents an interesting digression as to how much one could cool it down with fuel alone without running too rich (building up carbon) to alleviate the lessen air cooling ability of it's location.

    However more pertinant is the fact that you are using the TFI which unless I'm missing something it does not have the ability to (at least as far as user input goes) tune one cyclinder different than the other.

    A SERT, SEST or TTS does in fact have this ability but last time I checked they were not dedicated closed loop. Albeit one could concievably attempt to adjust the open loop maps based on input from a closed loop meter so as to attempt to map lookup tables to give you desired deviation from stoich from data inputted from the MAP, ION and TPS in real time.

    But it appears you are using the reports from the LM1 Wideband to manually tune your TFI after reading the meter on LM1 during operation. I kinda tend to think it would be better to use the front cylinder in this scenario since tuning it to the rear could cause to lean a mix in the front (since the TFI cannot separate the two settings).

    Further the ECM ( I assume you're still running an OEM ECM) is set to give the rear a tad more richness to alliveate the lack of cooling induced heat. So if you tune off the front I would "think" the ECM compensation would still effect correct results, but tuning off the rear might cause an undesirable scenario in the front.

    Anyhow that's my take on it, good luck with it. You know what would be cool is to hook it up on the front, read the ride and then switch to the rear and read the ride both before and after you change the TFI settings. Understandably that would be a bit of work but none-the-less interesting to record the data for decipher.

    ---------------------
    (To me) the Air - Fuel ratio is just another relationship to the end scenario, which is stoich or the deviation from it for desired results.

    Lambda does offer a compartmentalized view of this path, but it's all still about the same bottom line.

    AFR = xA/xF

    Lambda = AFR/AFR at Stoich

    Stoich is the scenario at which "all" the fuel is burned up in the combustion process. These is rarely possible and even when it reaches close parameters it can cause the engine to run hot.

    "How hot" it can take is what the EPA shoots for to save our precious environment that has somehow survired all the volcanoes, and organic waste gases since the dawn of time.
     
    Last edited: Apr 26, 2012
  8. 87gtNOS

    87gtNOS Member

    11
    0
    0
    RWB, you are looking too deep into this.

    If I richen up the mixture (tuning on the REAR cylinder) to cool the rear cylinder, it will do the same to the front.
     
  9. Hoople

    Hoople Account Removed

    7,198
    0
    34
    As far as a late model 96 goes... I have played with it. At a stoich ratio (14.6) the engine is hot. Bring it down much below 13.5 or so, and I found you reach a point of diminishing returns. You can have fuel dripping out the exhaust pipe and a 96 still overheat quickly. Now what I call overheating is when the front cylinder temperature reaches 295F. If heat management software is kicking in, your overheating, plain & simple. Bottom line is you just need moving air. Nothing else seems to work on these late model 96's.
    At least that has been my findings.
     
  10. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    Exactly and that is what I just said, you don't want to get the front running too rich. How deep is correct ?