The GM MAT and IAT sensor are both the same right ? Just curious because thats what it said on this site I was going to buy it at. But I also found a IAT sensor at extremepsi for 12$ and I have to order some other stuff from there so I would rather do it all in one spot. Anyone have any idea ?

Thanks.

 

Yes, its a GM IAT sensor, but we're using it in the manifold.

 

make sure to order the open element/fast response type.

 

if you're not bright enough to figure out that SD=speed density, then you probably should not be doing this conversion

 

I am assuming it is ok to use a log i took with the MAF setup to figure out my VE tables. I am trying to get a baseline SD map setup to test out tomorrow. I have a new FMIC coming so i am sure it will change when that is installed.

 

You'll want to get logs of baro & air temp corrected 2-byte load vs RPM and MAP in kPa. I'll post some pointers when I get to work.

 

I appreciate that. I assume 1-byte load will work too?

 

Thank you for porting it over. I look forward to trying this out soon.

I received my Omni-Power 4-bar MAP sensor and the IAT should show up in the next day or two. Would some of you experts help me out on scaling with this sensor?

Here is the information available on their website:
http://www.omnipowerusa.com/calibrations.doc

First, using a 5.00 volt supply, the maximum output of the sensor is 4.8volts=400kPa and the minimum charted value is 0.563 volts=50kPa. Charting out the values at 5V, if I set a linear regression with a y intercept of 0, I find the scaling to be kPa=83.806*volts with an R^2 value of 0.9998. Allowing an offset, I get kPa=82.894*volts+3.0925 with an R^2 of 0.9999.

Second, I've read somewhere that the 5 volt supply line is usually 5.05 VDC? A minor change that makes the maximum output ~4.848VDC instead of 4.80VDC. This is two counts at the maximum provided 0 counts=0 VDC and 255 counts=5.0 VDC.

Finally is the ADC a true 0 VDC = 0 counts, 5 VDC = 255 counts? Or is the actual input range different then 0-5VDC exactly?

 

I have the same sensor on order, so I would be curious to hear an answer to this as well.

 

I've been meaning to get to this, but had been too busy. For the Omni 4 bar MAP sensor, use this "MAP 16bit" scaling:

<scaling name="MAP 16bit" units="kPa" toexpr="x/2.5" frexpr="x*2.5" format="%.1f" min="0" max="450" inc="0.4" storagetype="uint16" endian="big"/>

Populate the MAP (kPa) input axis with values spanning ~10 to 400. As a first step, set the MAP VE load values equal to whatever values you put into the MAP (kPa) list. Some of these VE values will be too high, but its a good starting point. It may be necessary to tweak the MAP (kPA) values to focus on certain MAP ranges.

 

Cool, the car is still down, as I now have to pick up a new radiator and other miscellaneous crap, so it'll be a good few days before I can try anything. Thanks in advance though, good sir.

 

I messed around with the map sensor, a voltmeter and a potentiometer today and was able to answer a few of my questions while also finding a small issue with the Omni-Power MAP sensor.

The map sensor did not work at first. After talking with Steve at Omnipower, we were able to get the problem resolved. It turns out that the sensor pin out is not the same as factory. You will need to swap the two outer pins on the MAP sensor harness connector. I would suggest ordering directly from Omnipower and asking about this so you will know in advance if the wires will need to be swapped as they said they will likely be changing this to the factory pin out. Omnipower was great to work with though and I will definitely recommend others to do business with them. IMO, this is the sensor to buy over the 3bar JDM sensor simply because of the extended range. A stock turbo on E85 can max out the JDM 3bar...

The ADC seems to be a true 0-5VDC input as there was a 0 count until ~10mV and 255 happened at 4.99 VDC on my handheld.

Scaling in evoscan was straight forward, but I'm still trying to sort out the scaling in logworks2.0. It seems that simply writing the equation in the protocol.xml file is not enough to get the logging correct? You need to go into the channel configuration in the logger (and dashboard if desired) and set the range to match the range entered in the protocol.xml file? I haven't verified this with a fresh log, but I was able to get a log that was not displaying correctly to display correctly after making this change.

I'm using (x-52)*0.2368 as my scaling in logworks to get gauge pressure in PSI. The -52 offset is the raw bit count I get at atmospheric pressure (84.77 kPa). I have done this because I feel that because the resolution is in 0.2368 PSI increments with the 4bar that the pressure measurements may remain more stable with this scaling. Atmospheric pressure usually sticks within that range, using the raw bit count instead of subtracting a particular atmospheric pressure may provide a more stable boost reading and was easier as all I had to do was input the raw bit count with ignition on, engine off. Something like x*0.2368-(atmospheric pressure) should also work for logging though if that's easier to use or provides more accurate numbers?

EDIT: I also loaded up the MAP test settings used on the JDM 3bar that Mrfred came up with for 94170015. I'm not real sure what these values do, so I have no idea if they will be effective on thsi sensor. I'll give it a shot though and report back. Reading the requirements of the EGR test to happen though, I wouldn't be surprised if my driving style never even lets these tests run.

 

I am thinking we should have a separate thread for the omni 4 bar sensor that way the masses can find this great info.

 

I guess for those of us with 94170015 we still need to wait for the mat logging patch to be ported over, right ? I searched but I couldnt find anything for my rom.

Im not to sure Ill be going speed density right away but I do want to log my mat with a new fmic install coming up. I will start playing with it though. It seems if Im getting it right its just by changing the VE settings that you can now tune your car seeing you dont mess with your existing maps ?

 

heh. You're right, I haven't done that yet. I'll try to do that this weekend.