Initial chip settings

Discussion in 'All Topics, Chips, and Tech for Buicks' started by Tom Kelly, Apr 17, 2019.

  1. Tom Kelly

    Tom Kelly Active Member

    Eric, my chip is #12277 marked for 60lb injectors/alcohol/ timing 23/21 and less than 25 psi boost. I am going to be tuning with powerlogger and wideband sensor soon. I have been reading up on tuning and before I get started Ihave a question. The chip user guide indicates that for all four parameters "128" represents "base setting" I assume that for timing, this would be 23/21 for 1-2/3-4 gears. But as to fuel, does "base" refer to a predetermined lambda? Is it different for all cars or is it a conservative starting point (e.g. lambda of 83%). The reason I am asking is so I can get a feel for how much adjustment might be in order. The guide shows adjustment to fuel of +/- 20% which to my untrained eye seems ginormous. What can you tell me about the fuel starting point (128)?
    Thanks again for all your help to all of us.
    Tom
     
  2. Tom Kelly

    Tom Kelly Active Member

    I should have added that the reason I am wondering about what is a "reasonable" adjustment is that when I got the car, the TurboTweak installation guide was marked with a check next to "144" on the WOT fuel adjustment column. This would amount to a 12.5% positive change to fuel at WOT. Is this reasonable? I mean is an adjustment that large not unusual? Thanks
     
  3. EricM

    EricM Administrator Staff Member

    The chip is set up differently for different cars and combos. In your case the chip was set up to supply enough fuel at full throttle for approximately 25psi boost when using alcohol injection (usually target high 10's for AFR when using alcohol injection). The user adjustable parameters can add or subtract from the default fuel curve. There is quite a bit of adjustment, but if someone needs to add a lot of fuel then it needs a closer look. In other words, is everything working right (fuel pressure, MAF, alcohol, etc), and was the proper info given when the chip was made.

    The user parameters are there so the user can fine tune things if they so desire.
     
  4. Tom Kelly

    Tom Kelly Active Member

    Thanks. That makes sense. So it should be more or less fine the way it is but the proof will be in the pudding. Once I get to run it with the wideband and powerlogger I will know. And if I have to add/subtract a ton then something could be wrong. You mentioned fuel pressure. If a lean condition is detected during a WOT run (by lean I mean a/f well above your target of high tens) do you go right to the chip or do you look at fuel pressure? In other words, when do you suspect fuel pressure? When everything else doesn't help? Thanks so much for your patience on this.
     
  5. EricM

    EricM Administrator Staff Member

    Usually I would try to add some fuel using the chip parameters, and if it doesn't get any richer, then check the pressure at full boost to make sure its rising 1:1 with boost. Also, it's not uncommon for the alky pumps to get weak over time, which will also cause it to be too lean.
     
  6. Tom Kelly

    Tom Kelly Active Member

    Got it. This all makes sense. Thanks again.
     

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