Differences

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--- sdveadjsdratio [2009/06/14 13:53]
dmertz
+++ sdveadjsdratio [2024/03/15 11:16] (current)
@@ Line 11: / Line 11: @@
 The [[v3mafadjcombft|MAFComp Adjust (CombinedFT)]] page describes an excellent process for dialing in your mass airflow sensor.  Please read through this page carefully and make sure your mass airflow setup is calibrated as well as you can get it before attempting to use the **SD VE Adjust (SDRatio)** function.
@@ Line 21: / Line 30: @@
 ====== STEP 2: Data Capture ======
-To use this tool, you need to capture some data from your ECU while you drive around on the mass airflow sensor.
+To use this tool, you need to capture some data from your ECU while you drive around on the mass airflow sensor, before switching the Base MAF setting to Speed Density.
+**NOTE:**  As normally installed, first generation (not Gen 2 or MAFT Pro) MAF translators get their ground from ECU sensor ground via the Mitsubishi MAF connector and draw a moderate amount of current, particularly when powering the GM MAF sensor at higher airflow, so the pressure and temperature readings seen by the ECU will change a little if you later unplug the GM MAF or MAF translator, upsetting the VE table calibration.  Changing the translator's ground from ECU sensor ground to chassis ground instead will eliminate this effect. Cut the MAF translator's ground wire between the translator box and the Mitsubishi MAF connector and connect the end of this wire coming from the translator to chassis ground. Leave the wire end that remains on the translators Mitsubishi MAF connector isolated and insulated.
-{{  http://www.ecmtuning.com/images/forums/sddata/sdmaploc.png}}
+Add the following log items to your captured values (F10): SDRatio and MAP sensor.  If SDRatio does not appear as an item available for capture, you first need to define the MAP sensor input on the **Pin Assignments for Datalogging (PC-side)** of the **ECU Inputs** tab.
-Add the following log items to your captured values (F10): SDRatio and MAP sensor.  (If SDRatio does not appear as an item available for capture, you don't have the MAP sensor's input pin assignment configured in the display items on the ECU Inputs tab, and you need to do so.)
 **SDRatio and engine displacement:** It's very important to make sure SDRatio's engine displacement preference is set correctly to match your actual engine.  Do this by double clicking on SDRatio in the graph legend.
-The MAP sensor you want to log here is the one you have already configured in your **Manifold pressure (MAP)** field on the ECU Input tabs.  An example of this is shown here.  More details on configuring and installing this sensor can be found on the [[sdsetup|ECMLink - Speed Density Setup]] page.
+{{  https://www.ecmtuning.com/images/forums/sddata/sdmaploc.png}}The MAP sensor you want to log here is the one you have already configured in your **Manifold pressure (MAP)** field on the ECU Input tabs.  An example of this is shown here.  More details on configuring and installing this sensor can be found on the [[sdsetup|ECMLink - Speed Density Setup]] page.
 When attempting to initialize the **SD VE Adjust (SDRatio)** tool, the application will check your ECU Input tab to locate the MAP sensor.  It will then attempt to find this sensor in your datalog.  Using the image above as an example, you would want to log the GM 3-bar sensor attached to the MDP input in order to use this function.
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 ====== NOTES AND TIPS: Things to Keep in Mind ======
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 The downside, of course, is that if you disable the air temp sensor for speed density operation inside the ECU, then you need to make sure your air temperature reading while doing your calibration drive is fairly reasonable (say between 50-90F).  A good working intercooler and some careful attention to your right foot will help immensely with this too.
+Also, since the ECU's Baro input is in use by the Mitsubishi MAF sensor and unavailable for aftermarket-sensor connection, you'll have to use some other ECU input for the MAP sensor (at least until you switch full-time to speed-density and can then move the MAP sensor to the Baro input, if you so choose).
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 As long as the GM MAF stayed connected, the offset simply remained constant and you would never really notice much effect.  But when you switch to SD, you fully expect to disconnect the GM MAF sensor and that's when the offset makes a difference!  Suddenly the pressure sensor output changes relative to what it was when you were dialing the SD setup in using your GM MAF sensor.
-To ensure that this isn't a problem, you have to use one of our newer GM MAF cables that provide a separate power wire for the GM MAF's grounding point or you need to [[gmmafcablemod|modify our older GM MAF cable]] (if that's what you have) to add this wire.  If you're running a GM MAF Translator device, you could probably do the same ground wire modification as we recommend for our older GM MAF cables, but I can't guarantee that.
+To ensure that this isn't a problem, you have to use one of our newer GM MAF cables that provide a separate power wire for the GM MAF's grounding point or you need to [[gmmafcablemod|modify our older GM MAF cable]] (if that's what you have) to add this wire.
+If you're running a GM MAF Translator device, you need to do [[gmmafcablemod|a similar modification]] on their GM MAF connector as was detailed for our older cables.  This modification involves simply cutting the ground wire on the GM MAF connector and running it to chassis ground instead.

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