I am having difficulty setting up my values for the SOS 3bar in the AEM software for the gauge.

I can't seem to get anything even remotely accurate.

Any help, suggestions would be great.

 

What are the settings in the sensor setup screen?

You can start with the settings included in the instruction sheet then adjust the load offset with the igntion on (and car not running).

I checked the last car that we tuned and the settings were:

min: 0 V
max: 5 V
filter: 5
load offset: 3.5
scalar: 3.19

Try this, then check your reading with the engine off.

Cheers,
-- Chris

 

use the settings that Chris@SOS posted into the AEM PRO software so that the AEM itself is reading the MAP correctly. now in the PRO Gauge software scale the engine load with 0 = -15 and 255 = 29.4 and it should display correctly.

basically the AEM needs those other values to correctly see what's going on but the gauge doesn't use those settings. the gauge justs sees 0-255 from the ECU then displays a value that you enter in the table.

the gauge is a little annoying to set up but once it's set you'll love it

 

off topiuc qurestion, is this the oem direct replacement one?

 

Yes, it fits just like a factory sensor does.

http://www.scienceofspeed.com/products/eng...eed/MAP_Sensor/

-- Chris

 

Thanks guys, I REALLY appreciate the help.

I look forward to testing this out as soon as the rain stop!!

Thanks again!!

 

So I'm assuming b/c I set the parameters from -15 to 29.4 that it will show in psi and not percent?

I am a little confused as to how the guage works, and how it knows..

How do we know the lowest voltage it sees is -15 and the highest voltage it sees is 29.4?

Not that I don't believe ya, I'm just trying to understand how/why it works

 

The sheet of paper I got with the sensor wasn't working when my tuner tried to set it up.

Both the drop down boxers were supposed to be set to none, but we changed the top box to Map voltage and it seemed to work.

Your settings aren't like mine...mine are currently

min: 0 V
max: 4.75 V
filter: 0
load offset: 0.0
scalar: 3.00

Map Analog Input: Map Voltage
Map Period Input: NONE

 

a 3 bar sensor only shows 2 bar worth of boost. each bar = 14.7psi. so the first bar is atmospheric pressure. when you are full throttle in an na car, thats 0psi, or 1 bar.

so the 2 bar that it shows in boost is 14.7*2 = 29.4psi. the map sensor at full tilt or 5volts, which it is a 0-5 volt sensor, is 29.4psi, and at 0volt it is 29.4-3*14.7, or -14.7psi, which i suppose was rounded to -15psi.

 

yeah it's weird till you get used to it, 3 bar is from absolute 0 up to 3 bar over absolute 0 which is 44.1. what we're used to seeing as boost is just what's over 0 at sea level which is 14.7psi. so a 3 bar would show 2 bar over the pressure at sea level, so 44.1-14.7=29.4psi.

with the gauge it's a little weird, I can see why AEM does it this way but they should do a better job of explaining things with the gauge software. basically the sensor only outputs 0-5V and the AEM needs all those other settings to interpret what the voltage translates to in terms of engine load. 5V on the stock MAP sensor is supposed to be about 10.9psi and 5V on your new sensor would be 29.4psi, slight difference side note, I've seen a few stock MAP sensors not read past 9.5psi so if you're getting close to that number you may want to swap your MAP to make sure you're seeing the right stuff.

once the AEM is seeing the right thing you have to set up the gauge to interpret what the ECU is sending it. the ECU takes that voltage from the MAP (and any other 0-5V sensor) and scales it to a value from 0-255 which is 8 bit resolution, 256 steps including the 0. now the AEM just spits out 19 channels of data ranging from 0-255 to the gauge. the gauge software just tells the gauge what to display when it sees all that data.

it's kinda a lot of crap to set up initially. AEM makes it easier giving you base cals if you use their MAP sensors, or any other 2, 3.5, or 5 bar MAP sensor. otherwise you have to scale the MAP sensor part of the gauge cal before you'll see boost correctly.