Digifant II Performance chip (with actual gains) - Who'd be interested?

Discussion in '8-valve' started by NateS2, May 6, 2020.

  1. NateS2

    NateS2 Paid Member Paid Member

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    Yeah that's the bit than confuses me. The hall sender data is processed by the main processor first before being sent to pin 24 on the ECU and the second timing board. All I can think is he's changing the logic of the main processor to "fudge" this RPM signal. So maybe the engine is at 3000 RPM, but his code makes the output to the second board pulse as if the engine is it 4000 RPM for example, so you can gain rudimentary control over the timing that way.
    But you could do that with any version of the timing chip, so maybe the "two letter" ECU's have timing maps on the second chip that are more aggressive to begin with, or if you pretend the engine is at some crazy RPM like 9000 you get access to more timing values. I'll have to investigate.
     
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  2. watercooled Forum Member

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    Total novice here but used name brand chip and felt slight gain with RV 8v Diji on Neuspeed mild street cam ,the maker said 5hp for the chip,next engine swap was with Techtonics cam and their cam chip ,really hauled with a more developed 2.0 litre 3a audi engine ,but really think the gains on a standard motor are somewhat limited.
    Seems if a motor is modified the gains seem to be better....
     
  3. NateS2

    NateS2 Paid Member Paid Member

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    Yeah I thin realistically that's always going to be the case. The standard engine and ECU were tuned at the factory to give almost the max output and good driveability, and with NA there's obviously only so much more you can extract. But when you start modifying the hardware the ECU calibration will no longer match up, so having a chip that's more suited to your mods will help a huge amount, that's hopefully what I want to do.
     
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  4. NateS2

    NateS2 Paid Member Paid Member

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    So ignore my previous post, after looking further there is no way at all the main fuel processor can adjust timing. I have no idea what Digifast does but it isn't anything to do with timing. Below are the pins that connect the two boards. Green are pins that are connected to the fuel board ADC, aka no output can be commanded on these pins. Blue are interrupts, so again, no output. Red is output from the ignition controller so again not relevant. Finally, the knock sensor is not connected to the fuel processor at all, and the DIAG line is not connected to the ignition processor in most ECU's.
    AN7 isn't used normally, its just tied to ground, but I believe its designed for internal MAP sensor. Maybe Digi 2 was once intended for boost operation? Or maybe just better control of NA engines?
    upload_2021-6-3_22-28-58.png
     
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  5. Mario_Marques New Member

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    Hello Nate, any new update on your work?
     
  6. Mario_Marques New Member

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    Hello Nate, still looking for your updates. :⁠-⁠)
     
  7. Mario_Marques New Member

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    Just another thumbs up for Nate, I hpe he didn't quit.
     
  8. KeithMac Forum Junkie

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    Would you not be wise to look into coding in a routine to use a decent free flowing MAF?, I use a Hotwire MAF sensor on my GTO with good effect.

    You mentioned TPS based load mapping earlier (alpha-n), a proper mass airflow sensor is better all round imho.

    I re-wrote a fair bit of MegaSquirt firmware (in ASM) a long while back, the more you look at it the easier it gets.

    My 16vG60 never liked the Digi 1 ecu, maybe due to low vacuum using the Kent 1602r cams.
     
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