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Thread: Supercharger/cam ignition timing

  1. #1
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    Default Supercharger/cam ignition timing

    So I am using the Diablo sport predator tune that came with my Supercharger as a base tune. So it is not adjusted for the cam that I'm running.

    According to the tune, they quit adding more fuel at 4800 rpm. My question is, now that I have adjusted for the fuel on the high end, do I need to change the spark timing more to maintain a rich mixture? My afr shows that around 5000 rpm it starts to lean out. It gets leaner then 15 at 5800 rpm. Any help and input would be appreciated. Also, do I need to adjust the pulse width of the injectors to accommodate for the higher lift and longer duration?

  2. #2
    Joe (Moderator) joecar's Avatar
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    Add more fuel at higher rpm.

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    I'm already down to a .5 lambda and it's still running lean.

  4. #4
    Joe (Moderator) joecar's Avatar
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    0.5 lambda from your wideband...?

    You said:
    My afr shows that around 5000 rpm it starts to lean out. It gets leaner than 15 at 5800 rpm.

    Post a log file.


    You need to set the IFR table (possibly scaled) and get VE and MAF tables corrected... then the commanded PE fuel will be what you get (measured with wideband).

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    No but the commanded fuel is at. 05. Idle and lower rpm is right around 14.2-15.2. Then under boost it richens up as its commanded to. But high end just kind of quits and starts to lean out. I'll get the tune from the guy that is helping me. He is more of a diesel tuner though...

  6. #6
    Lifetime Member limited cv8r's Avatar
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    Has your fuel system been upgraded? Maybe your just running out of fuel?
    It's all good until it goes "Bang"

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    Right, I thought that I might just be running out but with what I'm running it should support around 525 horse at the flex plate and I don't think that I'm quite to that level of power

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    Lifetime Member limited cv8r's Avatar
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    What is your injector duty cycle & fuel pressure doing? They will be good indicators if you fuel system is lacking & your adding a lot of fuel to the tune & its not helping.
    It's all good until it goes "Bang"

  9. #9
    Joe (Moderator) joecar's Avatar
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    Good point (thanks cv8r)...

    Kmb, describe your fuel system (from rear to front).

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    It is the factory flex fuel pump with factory rails and 42 lb high impedance injectors.

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