Like the title says, what MAP sensor should I use if I'll be running up to 18 psi on a turbo build? The duramax MAP looks good, (part # 12623671) but I don't know if that's the best option.

 

You will definitely want to be 3 bar, but I'm not sure which sensor you need exactly.

 

A 2 bar sensor is good for about 15 PSI. A 2.5 bar sensor is good for about 22 PSI. I make the 2.5 bar sensor as GM does not make them. I just finished 2 of them about an hour ago. If you are interested, I sell them for $70 shipped to the lower 48.

 

I used the MSD version of the 3 bar block style map. I would use it again.

 

I'm using Gadetized 2.5 bar map, I can vouch for it.

 

Just to inform people of the problems with diesel MAP sensors. A diesel engine does not create engine vacuum like a gas engine. When you let off the gas on decel, the kPa drops down. The sensor above (12623671) only goes down to 36 kPa, so anything below that is not recognized and will cause a rich condition. You more than likely will not be happy with a sensor designed for a diesel engine. I honestly don't care if someone purchases from me, but just be aware if you want a Duramax sensor.

 

You can also use a cobalt ss map sensor. I'm pretty sure they are 2.5 bar and may even come in a 3 bar, not exactly sure on the 3 bar.

 

No. Cobalt ss is 2 bar

 

Cobalt ss TMAP sensor number 90423637 (2.5 BAR)
Pigtail for TMAP sensor number 88988320

there are two different map sensors that came in the cobalt tc. one was a 2 bar direct plug in for the ls engine and the 2.5 bar is a 4 wire plug which has the ait sensor in it.





not sure if this is correct, but maybe worth looking into?

 

bumping this up... when tuning for the 2.5 bar do you use the 3 bar OS?