Zip Corvettes

testing the interest in a 2 bar map sensor for the 05, but it will also work on the 97-04. The calibration of the sensor would not go negative like the current 2 bar GM sensor so you could use it in the LS1B and E40 ECU's. The retail price would be $69.95.

DSteck

The GM 2 bar MAP sensor doesn't have a negative offset. The E40 TBSS I'm driving right now has one.

12580698 is $63.34 shipped from GM Parts Direct.

Zip Corvettes

I thought I looked at that sensor a couple of months ago and it had a negative offset. What was the factory application for that.
Thanks

DSteck

It's a Cobalt MAP sensor.

5 Liter Eater

It's the 3 bar sensor that will plug in but won't work with the E40 as the table maxes out at 2.5 bar which is why I made one and DSteck makes/made them.

DSteck

I have a 3 bar core too that doesn't have a negative offset.

Zip Corvettes

That number doesnt appear to be a good number anymore.

Zip Corvettes

Just pulled a file for a 05 Cobalt, the MAP table is 270.59 kpa with a -3.30 kpa offset.

DSteck

That's the 2.5 bar TMAP. This one is a baro sensor. I don't know the exact application.

Zip Corvettes

Why would they make the baro sensor go 2 bar? Not really asking the question because I know you didn't design it, but odd. Also if it is the baro sensor how do we know it does not have an offset. I don't see it's calibration in any software.

JDS99

I have the one you made me in my '99. Works great. 3 bar, positive offset, good transient response. Even customized to bolt into my Ls3 intake manifold but be plug and play in my C5.

DSteck

How do we know? God invented data sheets.

Zip Corvettes

???

lt1z

Listen to Steck on this one

DSteck

There's a manufacturer data sheet for the 2 bar. I think it was also used on some Grand Prix GTPs. I know I found one on an early NA Cobalt at the salvage yard.

Zip Corvettes

Have you actually confirmed in the car that it is right on. Correct me if I am wrong but all the sensors are from 0-4.5 (5)v. The offset is what is required to get the sensor reading the correct MAP in the car. So really or very low voltage should be 0 kpa but it's not so there is an offset to get this correct. My question to you on this sensor is that part number came back as a baro sensor, not sure why it would be 2 bar, but hey GM has done some odd stuff before. The manufacture's data sheet would get the linear reading from 0-4.5 volts, my question is does that need an offset?
The MAP sensor in the cobalt shows an offset but it does not give one for a baro sensor. I do not have any factory Cobalt files to go look and find the baro sensor offset.

Zip Corvettes

I would prefer to be dead on. It used to be said to just blow the numbers up at 101KPA and all would be well, but we know that is not the case. Just trying to make a sensor that would be dead on. If there is one that exists that would even be better than me having to spend money to make one.

DSteck

I'm totally wrong and have no idea what I'm talking about. Good luck.

Zip Corvettes

Dsteck,
Don't be smart about it. I am trying to find a solution and you are saying to just go with it. That is just like me telling you to go with the cheap 60# injectors and they work.
My question is where does the offset come from then and have you tested that MAP you are using to see how accurate it is? I don't remeber where I saw the offset on the Cobalt at but I think it was a -3 kpa, do we even need to worry about 3 kpa difference. If I can find a GM cal I will look and see what the cal is on the baro sensor.

DSteck

Instead of insisting I'm wrong, do your research.

All the Delphi 2 bar sensors use the same internal core element with the same calibration curve. 200kPa linear value, 8kPa offset value.

http://www.powerandsignal.com/Products/Pressure.aspx

Yes, I've tested it. I've tested it on the numerous cars I've tuned. I've tested it my personal TBSS which runs one. I've tested them on my own bench testing equipment that I have built (which is used for verifying my 2.5 and 3 bar sensors). I've done my homework. I'm not a shoot from the hip clown.

Why rely on trying to hunt down a calibration file when you can get the information needed STRAIGHT FROM THE MANUFACTURER'S DATA SHEET.

Sorry if I'm not cheery and bright when somebody repeatedly posts that I'm essentially talking out of my ***.