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MAP Sensor Limitations..

Discussion in 'Forced Induction' started by livinnvtec, Jul 30, 2005.

  1. livinnvtec

    livinnvtec Junior Member

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    Can a p28(Uberdata) Safely run a turboed car? The main reason why I ask is temperature:

    1: Map sensors calculate lbs/min, they don't actually measure it

    2: We use the IAT to calculate the temperature part in the requirement

    3: These sensors(I would imagine) would have a usuable range of temperatures (Think O2 sensor Wideband vs Narrowband). Would the air coming out of the compressor, or past the intercooler, fall in this range?

    How accurate would it be? I live in Pembroke Pines Fl, and over here, the winter in the day gets to 90F and in the night 55-60F would I have to run two chips?
     
  2. Slo86GT

    Slo86GT Super Moderator

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    What you wonder is exactly why there is an IAT sensor on the motor.

    The IAT is good for everything from Canadian winter climates to desert heat plus engine bay added to it, so I wouldn't worry about it's range of operation.

    The air coming out of an efficient intercooler should be within normal temperatures. If it goes outside these ranges, you're asking for trouble from inferior intercooling, which can be worse for a motor than a simple (yet effective) tuning method.

    My intercooler setup has IAT's now that stay within 10-15 degrees above ambient temperatures. Meaning, no matter how hot the air coming out of the compressor is, I can grab the piping at the throttle body and it's only slightly warmer than normal air, barely warm to the touch, whereas at the compressor outlet, the piping will boil water that's dripped on it.

    Airflow is calculated by the P28 using tables that are assigned by Hondata, Uberdata, Turboedit, whatever program you are using. The factory p28 figures are thrown out the window, even though the same tables are used.

    Load/RPM is an excellent tuning strategy. The only time it WON'T work well is when boost comes on hard at part throttle. The car may go rich because of airflow limited by the TB even through the MAP will still see max boost. Oh, wah. Clean off the plugs with a good WOT run, and you're good to go. ;)
     
  3. livinnvtec

    livinnvtec Junior Member

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    Awesome about it being clsoe to ambient temperature. The only thign I was wondering is the equation that the ecu's use to calculate to get lbs/min can you correct the value given based off temperature? Doens't look like there would be anything practical for it(My curiousity that is)
     
  4. pissedoffsol

    pissedoffsol RETIRED

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    with my big-ass FMIC, i was actually seeing LESS than ambiant on the DYNO.

    meaning, just the big-ass fan for air flow.

    it was about 103 in the shop that day, and my iat's were in the mid 90's.


    the map sensor converts load pressure in milibars into a voltage. it sends that voltage to the ecu.
    the ecu is smart, and looks to the iat and other sensors, and will adjust what needs to be adjusted for you.

    50 to 90 isn't a big jump at all, and i wouldn't even worry about it.

    at the most, some folks do a winter tune, and a summer tune.
     
  5. livinnvtec

    livinnvtec Junior Member

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    Thanks alot to both of you!
     
  6. Slo86GT

    Slo86GT Super Moderator

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    Sorry B, but with an air cooled intercooler, without any additional cooling source other than ambient air, that isn't feasible. It might have been REALLY REALLY close to ambient air temp, or the thermostat that was used for ambient readings was in a hotter area of the shop or something. I'm thinking the ambient reading they used was jacked by surface heating from the sun or something.

    Just think about it. You'll get what I mean.
     
  7. pissedoffsol

    pissedoffsol RETIRED

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    could be... but the temp on my dyno showed 103 i think it was, and the hondata datalogs showed 93-98 at the iat.

    who knows...
     
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