How do i convert a DSMlink to speed density

Posted by turboglenn, Apr 5, 2008

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  1. turboglenn

    turboglenn Proven Member

    Joined Nov 5, 2007
    RIpley, West Virginia
    Just as the title says. What do i need to do to convert my friends MAF setup running DSMlink to speed density where he only needs a 3 bar MAP and IAT sensor instead, or can it be done?

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  2. gsxtasy

    gsxtasy Proven Member

    Joined Oct 17, 2002
    Lincoln, Nebraska
    Can't be done. Yet. When V3 comes out, it will support speed density, and it will natively run a gm maf(no transator needed). Will be awesome, if it ever comes out.

    Can i ask why he want's to? The maf setup is very good, and if you over run it, or rev too high, it is capable of a simulated speed density pretty much. Use a map sensor and fake maf signal and it will extrapolate the figures for you.
    My DSM:
  3. absolute_DSM

    absolute_DSM Proven Member

    Joined Jan 29, 2006
    Boise, Idaho
    If hes running a 1g, Glenn, he could run DSmap for cheaper and run speed density. ^ But Aaron is correct.
  4. JeffGST

    JeffGST Proven Member

    Joined Mar 9, 2002
    Las Vegas, Nevada
    V2 has Speed Density features already. I use it.

    All you need is a MAP sensor (no intake temp), but you still need to use a MAF for idle and part throttle conditions. You activate "Fake MAF" + "Use MAP" and there you have it, Speed Density.

    You tell the ECU at what MAF Hz that you want to ignore it and instead use the MAP sensor to calculate injector duty cycles.
  5. Steve93Talon

    Steve93Talon Proven Member

    Joined Jan 20, 2005
    Philly Burbs, Pennsylvania
    Tom and Dave have said V3 "might" have speed density support, but the last thing I've heard from them indicates it isn't going to happen.

    You could theoretically use a MAFT-pro to run speed density with DSMlink, but why would you? A 2G or EVO MAF works flawlessly, and as Jeff said, you can clamp it and use a MAP sensor to effectively go SD if you overrun the MAF.
    My DSM:
    1993 Eagle Talon TSi

    11.784 @ 115.120 MPH
  6. MarsaGSX

    MarsaGSX Proven Member

    Joined Feb 15, 2004
    Czech republic,, Europe

    Do I need calibrate GM Maf when use "USE MAP" +"USE MAP"
    just click on this two fautures and tada..done??Cus I did that calibrating.. and my Boost est is way off my GM3Bar Map..
    How do I tell the ECU what MAF Hz I wants ignore MAF??
    My DSM:
    1995 Mitsubishi Eclipse GSX

    Drag Race Build

    GT42   automatic
    1995 Mitsubishi Eclipse GSX

    11.170 @ 129.270 MPH
  7. 1992awdlaser

    1992awdlaser Proven Member

    Joined Dec 5, 2004
    Wallace, North Carolina
    I would think you have to calibrate the maf if the ecu is going to be going off of its readings at all when full throttle.

    Go to ecu/logfile and click on airflow. You will see on the right side of the box that opens a spot that says "switch over".
  8. snowborder714

    snowborder714 Moderator

    Joined Oct 15, 2006
    Mechanicsburg, Pennsylvania
    Here's how to calibrate the MAF-T using a map sensor:
    maftcalibrationbyloggedboost [ECMTuning - wiki]
    My DSM:
    1995 Mitsubishi Eclipse GST

    12.529 @ 110.820 MPH
  9. 2gGSX

    2gGSX Proven Member

    Joined Feb 15, 2004
    St. Louis, Missouri
    This is correct. The FakeMAF feature is dependent on airflow metering at the switchover point, meaning if your metering is off at the switchover then it will be off by that much for the rest of the RPM band.
  10. spoonman

    spoonman Supporting VIP

    Joined Jul 20, 2007
    Omaha, Nebraska
    DSmap is the best and cheapest way to run speed density.

  11. turboglenn

    turboglenn Proven Member

    Joined Nov 5, 2007
    RIpley, West Virginia
    I was just wondering that's all. drdouglas had asked me about the difference and if his could be changed to MAP instead of MAF, so i am just doing some leg work to find out how. But it's nothing we are too worried about
  12. JeffGST

    JeffGST Proven Member

    Joined Mar 9, 2002
    Las Vegas, Nevada
    Yes, you need to calibrate the MAF up until the switchover point. Just as stated above, if your airflow calibration is off at the switchover point, it will also be inaccurate by the same amount once in SD mode.

    I switchover at 2400Hz because there is an airflow slider right at that frequency. Therefore it is very easy to calibrate right at that frequency.

    Did you do the correct math regarding your calibration. All you need to do is plug in the BoostEst and Actual boost data, into my formula on my website. I can calibrate a MAF with one 3rd gear datalog.

    Here is my log with Fake MAF + Use Map activated. Notice how the AEM5Bar and BoostEst are lined up perfectly at my 2400Hz switchover and then it begins to diverge as VE drops when you get closer to redline.


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