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Thread: 14point7 UAFC fuel piggyback review

  1. #1
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    14point7 UAFC fuel piggyback review

    If you want to make a simple adjustment to your fuel map and not spend much money, this might be what you need.

    The 14point7 UAFC intercepts the MAF or MAP voltage signal and adjusts it according to user defined tables, before passing on the adjusted voltage signal to the ECU. The ECU responds by adjusting the injector pulse width to match the voltage signal according to itís stock fuel map. The UAFC map (actually three maps, switchable on the fly) has two user definable global axes, voltage and RPM, so can be configured to suit your engine characteristics, and values are set as a percentage of the incoming voltage signal. For example, a value of 110 in a cell in the fuel table adds 10% more voltage to the outgoing signal compared to the incoming signal.
    The unit is made in Canada, and sells for $CAD125, which with shipping was about $AUD200 delivered to Sydney. We got it to sort out the fuel map in our stock Suzuki Swift track car, which runs too rich at full load and high RPM, about 0.77 Lambda.



    The good points:

    • Simple to wire in, just splice it into the MAP or MAF signal wire, add RPM signal, power and earth and itís ready to go.
    • Small and lightweight, a little bit bigger than a box of matches.
    • Simple UI for programming from a Windows laptop.
    • Data logging. We were able to connect our wide band and log up to 30 minutes. Itís got an additional analog data logging channel, if nothing else, you could use this unit as a cheap data logger.
    • Switching between 3 maps on the fly. We mounted it so the driver could reach the unit strapped in.
    • Excellent support from the manufacturer. When I emailed explaining I was having some issues, they sent me another unit without me even asking.




    The challenges/shortcomings

    • Itís unlikely to work in closed loop, as the ECU would presumably try to trim out whatever adjustments were made in the fuel table.
    • Not sure if it would work with wide band 02 sensors, again the stock ECU might try to compensate.
    • Definitely doesnít work with frequency type (Karmen Vortex) MAF sensors.



    We had a few issues sorting it out and getting it working as expected. Initially it could not pick up an RPM signal. The documentation says the RPM signal should be picked up from the coil, but with coil-on-plug the only signal we could get that worked was from one of the injectors.
    The next challenge was that the spliced in wires to the MAF were picking up interference, which resulted in fluctuating voltage signals going into the UAFC. This took a while to figure out, to resolve it we had to install shielded wiring, thanks to a tipoff from Jason Broadhurst.
    We also found the screws in the cheap connector that it ships with had a habit of coming loose, which resulted in some erattic behavior by the ECU as it received incorrect voltage signals from the UAFC.

    The result

    The car was dynoíed at Motorsport Wiring in Seven Hills (Highly recommended, the proprietor Chad is super helpful) the end result was we got the mixture sorted out, with the lambda now at 0.88 at max power, picked up a few extra KW, and a new PR at the track.

  2. #2
    Purist, whats that? Jason Broadhurst's Avatar
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    Closed loop wise. The 14point7 or any good wideband, has a programmable output. so if you want to cruise at 15.0, program your wideband controller to output 14.7 when it's at 15.0 so the ECU controls to a process variable.

    It's what I did on my Magna years ago with a few resistors and a PIC micro on the narrowband sensor.
    Jason Broadhurst

    Someone once asked me if they could use my mower. I said "sure, so long as it doesn't leave my yard"

  3. #3
    <3 Gate Rollin's Avatar
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    This sounds like a good patch for jimny owners when they swap the pathetic 1.3 for a 1.5/1.8

    Sent from my GT-I9505 using Tapatalk
    Quote Originally Posted by jmac
    But on seatbelts - I don't think they should be mandatory for adults, but for under 18s. I reckon make them mandatory up till then, and provide plenty of graphic evidence supporting their use to school age children, and then if they hit adulthood and don't choose to wear them, think of the future without these fucken idiots around...

  4. #4
    Registered User E-Z's Avatar
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    caprice nugget.

  5. #5
    What's that whooshing? Aaron's Avatar
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    The DFA works much the same - less resolution considering they're what 15+ years old now? - BTW if anyone wants a DFA I have a mostly assembled one you can have for beer money
    ---
    Shed Project: 1994 Laser Lynx with BP-T

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