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Ap1Chief
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Map sensor as a Spare Pressure input

 

So I have a stock honda map sensor connected to my valve cover to start monitoring crank case pressure. I thought it would be easy enough to throw in the max min scalar and offset from the stock map sensor wizard and it would read correctly. But this is not the case. Im using the "spare pressure1 input" and im using ADCR11 pin as the signal wire,grabbing 5v output from c28 which is a 5v sensor output.  Im getting a good volt reading at atmospheric pressure as 2.9v and when i apply Vacuum and or pressure the volts swing in the correct ways, but the map sensor settings must be different on the "MAP" channel the the PRESSURE input channels, cause this is not showing vac unless i start playing with the offset and scalar alot, than its not reading the correct levels.  If anyone can help get this thing to read right that would be awesome!  thanks guys

 

 

 

 

 

AEM_NS
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Joined: 06/06/2014 - 09:31
You're right - MAP and other

You're right - MAP and other pressure inputs are scaled differently.  You can steal the standard Honda MAP sensor scaling values from Infinity Tuner:

Throw that in Excel and you'll get a scalar and offset value and you can do some math to change the units too.  But honestly, since this isn't a MAP input, there isn't any filtering so you're going to see a very noisy signal.  Why not just log the voltage and apply a transfer function with filtering in AEMData?  Do you really need to see a live scaled value in the software?

 

Ap1Chief
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Yep actually was thinking of

Yep actually was thinking of doing that last night, I got to play with aem data on how to show me what i want to see lol but yes, probably just log the voltage and do math in my head or have aem data do it. 
What options do I go into to get data to show me what I'm looking for?

AEM_NS
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https://www.youtube.com/watch
Ap1Chief
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Heres my data i got using the

Heres my data i got using the stock honda map sensor settings in Spare pressure input. trying to see where i can input this to get me a nice reading. .85v = -9psi  2.95v = 0 psi 4.4v = 8.5psi

 

AEM_NS
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You can plot it in Excel, add

You can plot it in Excel, add a trendline to get a slope and intercept which would be your scalar and offset for a math channel in AEMData.

Ap1Chief
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Joined: 04/13/2020 - 17:40
Im in aem data now, trying to

Im in aem data now, trying to figure out what the math equation is with this data I have.. i dont have excel on my laptop :/

Ap1Chief
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ok so we got all the math

ok so we got all the math right in kpa... when trying to convert the display to say inhg its wrong.. at 110kpa which its showing correct kpa, its telling me its 33 inHG its like the display is backwards on INhg

Ap1Chief
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I got it we made another math

I got it we made another math equation and applied kpa convert to PSI and its working... NOW how do i save thise math stuff in AEM data so i dont have to keep doing this lol 

Ap1Chief
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Export found it! lol 

Export found it! lol 

AEM_NS
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Ap1Chief wrote: ok so we got

Ap1Chief wrote:
ok so we got all the math right in kpa... when trying to convert the display to say inhg its wrong.. at 110kpa which its showing correct kpa, its telling me its 33 inHG its like the display is backwards on INhg

KPA is absolute and so is InHg.  110 KPA = 33 InHg so it was exactly right but it sounds like you want gauged so you'd have to apply a -30 offset to get it to read as gauged.