Quick question on 2 BAR map charateristics

I know when you load the 2 Bar OS the MAP characteristics changes automatically to Map Sensor linear - 200 and Map Sensor Offset to 10.33.............My 1 Bar original settings are 94.43 and 10.33...........I know there has been this whole debate on whether the Offset should be 10.33, 8, 9.07, etc...........My question is, " does HP tuner software actually change both settings or just the Linear? If I saw them actually change in my setup I would not be asking this question. I know 100% that my 1 Bar settings are dead on with my local barometer...

Thanks, Tony

Ok, I will answer it myself then......The 200 / 10.33 that is changed automatically in HP tuners does NOT jive in my area (NJ). My barometer and manifold pressure were too high. I even tried 207\9 which is shown on other sites for a GM 2 Bar......This was also not accurate and still too high..............I went with 200/8 which changed in HP tuners to 200/8.01 for some reason but it was now accurate.......Maybe I am just too damn anal, but I like things accurate....

What p/n sensor and where'd the data come from? Applying the custom OS doesn't change anything about the accuracy of the settings or data returned from the sensor.

I change the data to match which sensor is installed. Past that if I have to change the offset setting slightly I will. Then it would get closer to where I need it to read for my area.

Like just say I do live right around sea level and it's what you'd call a perfect day. About 72-77 degrees with no humidity or anything. The kpa should be reading right around 99-100ish but my log shows 97kpa with KOEO. I may slightly adjust the settings a hair to get me closer to 100kpa, then I call it good and go on my way.

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Originally Posted by blindsquirrel

What p/n sensor and where'd the data come from? Applying the custom OS doesn't change anything about the accuracy of the settings or data returned from the sensor.

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I used the GM Cobolt sensor part number 1215136.............I know Aaron on here told me to use 200/8 which is what works well for me.....But if you were to load the 2 OS it changes the MAP sensor characteristics to 200/10.33 which is not accurate for my area.....Not sure why HP tuners changes those settings, perhaps its just a canned set of parameters that are meant to be changed.

I was particular about getting my baro numbers for my area.....Its was 1026 hPa........which coverts to 14.8psi......and 30.29 inch or merc.....KOEO is about 102.....I think I am close enough and happy that the car idles and revs nicely.....need to get it back on the road soon...

LOL, the default settings aren't specific to any particular part number sensor, they are just placeholders. The actual specs for however many dozens of "2-bar" sensors there are out there are all over the place.

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Originally Posted by blindsquirrel

LOL, the default settings aren't specific to any particular part number sensor, they are just placeholders. The actual specs for however many dozens of "2-bar" sensors there are out there are all over the place.

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Yes, I agree.....But with the research I did on the "many" forums some folks took the HP tuners 2 bar characteristics as gospel. I was skeptical from the get -go and did try to inquire on this site, but no reply from the HP tuner folks... I do agree the characteristics are all over the place and its just one of those things that always happens when you get responses from folks on the internet....There are a handful of folks that I really trust based upon the info they put out and the accuracy of it...

No, I meant that there is no one single correct answer to the question, "What linear and offset is correct for a '2-bar' MAP sensor?", without knowing which exact part number sensor you're talking about. Once you nail it down to a specific part number, yes, internets being what they are, and opinions being like... you will get various answers to "What linear and offset is correct for the 2007 Cobalt 2-bar sensor, 12615136?", but there IS one single correct answer to that one.

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Originally Posted by blindsquirrel

No, I meant that there is no one single correct answer to the question, "What linear and offset is correct for a '2-bar' MAP sensor?", without knowing which exact part number sensor you're talking about. Once you nail it down to a specific part number, yes, internets being what they are, and opinions being like... you will get various answers to "What linear and offset is correct for the 2007 Cobalt 2-bar sensor, 12615136?", but there IS one single correct answer to that one.

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Yes, I understand .......So what is the correct answer for the part number you show, which I mentioned earlier? And where did you get your data? I tried looking it up via part number and it was not conclusive with the sites I read

I don't use that sensor, I have a homemade cobbled-together thing with a Freescale/NXP 2.5 bar in it, which has an actual real no-BS datasheet available.


(hint: you have a stock MAP and know the stock offset (no reason to suspect those aren't accurate enough for this), you can use that as a tool to find the actual KOEO reading, which can be used to find the new sensor's offset...)

Yes, it seems to be spot on based upon some scans today.....acts just like my original one did in that KOEO is in line with the current baro in my town.....And after I drive for awhile it goes up to 15.1 or so...Did it today and did it everytime with my stock one bar sensor. I have no reason to believe its not working properly......In any event, I am scheduled to see my tuner this friday for a nice SD tune..I did my part to get her ready for the hour and half drive....