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jovanny

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Posts posted by jovanny

  1. I by no means covered it all but just to get an idea and if I am off on the numbers a little bit its just examples LOL----

     

    To be kinda brief, which I don't think there is a way to be LOL... 2bar and 3bar are measurements of atmospheric pressure but the definition of mapping gets less detailed as you go up in bars... Just as an example, lets say Atmospheric pressure is 100KPA,(105KPA I beleive stock sensors go up to) thus a standard NA vechicle will be equiped with a 1bar MAP sensor... Now if you are supercharged, or turboed and forcing more air/oxygen than what the engine naturally can suck, then you will be reading above 100KPA and a 2bar (200KPA) MAP sensor is needed to accuratley read boost pressures... For instance at 10PSI boost you may read 175-185KPA while at 20PSI you will read maybe 250 or little more KPA... Thus a 2.5BAR MAP would be required for more accurate tuning since it will read up around 250KPA... A 3BAR most likely will never be needed for most people except in very high boost applications...

     

    As far as Speed density goes, for a short answer :rolleyes: , SD takes readings from the IAT sensor, MAP sensor, and RPM TPS... Thus not needing the MAF Sensor if your IAT is relocated... In general a SD is used on more aggressive FI motors that go above the boundries of what a MAF can read... Generally anything above 10-12PSI of boost is maxing out a stock MAF sensor and a SD tune or larger aftermarket MAF is required, but the only way to know if it is, is to do a data log and measuring MAF in HZ to see if it is going above the maximum HZ allowed by the stock MAF... SD is also said to be more affected by drastic weather changes and elevation changes because of the set programming in the PCM required to run SD since a SD tune has know way of reading actual air intake... Thus used only for Higher horsepower and higher Boosted motors which are NOT normally driven as DD's or cross country... Some will say its fine and others say absolutley no, also you can justify it if you live in a climate that has a fairly steady climate year round unlike me where it goes from 100's in the summer to -50 below in the winter, Fortunatley I have another DD and only drive my SSS in the summer and I also run SD Tune due to pushing the limits of my stock MAF and wanting to eliminate it all together LOL... Here are a couple of reference pages I quickly found....

     

     

    http://www.pcmforless.com/index.php?option=com_content&view=article&id=126:speed-density-sd-vs-mass-air-flow-maf-&catid=34:tuning&Itemid=56

     

    http://ls1tech.com/forums/pcm-diagnostics-tuning/1195505-maf-vs-speed-density.html

    It would be cool to know what all that means !

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