How to tell if i have a 3bar map sensor?

[dsm10o0]

I got 2 gm MAP sensors as im piecing together my speed density stuff.

How do i know/tell if these are 3-bar map sensors? I got one of them from a 4 cyl. saturn and the other is from a v6 buick.

numbers on them are
103 7259
on top:
466
back:
35
17406

other one is
039 5051
top:
466
back: AA-5


let me know, thanks

 

[prove_it]

I'm pretty sure if you pulled them from non turbo gm products they will not work. Only turbo model GM cars came with sensors capable of reading postive pressure.

Again, I think so, could be wrong.

 

[dsm10o0]

oh ok. thanks. also, which one do i need? 3 bar map or a 4 bar? I plan to boost around 18-22 psi

 

Bar is just another form of pressure reading. I didnt realize it at first myself.

click

3 bar is 43.51 psi. So a 3 bar map sensor would work fine for you unless you plan to run more than 43.51 psi of boost.

 

[dsm10o0]

alright cool. thanks. Now i gotta figure out what this sensor is.

 

[mikus]

+1 for needs to be a turbo application.
I recall hearing that only the illustrious 89 trans am turbo had one that's a fit for ECMlink/SD, but I would guess others out there could work (but not those you have)

 

just a quick note...yes 3 bar = 43.51 psi however you have to subtract atmospheric pressure from that (14.7 psi) which equals about 28.8 psi of boost before the map sensor is maxed out....just fyi :-D

 

Thanks chevyracer, I was unaware of that.

 

not a problem /ubbthreads/images/graemlins/smile.gif....I didnt realize it myself until I got bored and looked it up........basically its just absolute pressure - atmospheric pressure = gage pressure......the 14.7 psi is "standard" atm pressure but it is a little different (+/-) about 1 psi depending on where you live.

 

[prove_it]

^agreed

I believe that all sensors are sold advertising their range. Always subtract 1 bar for your vacuum readings. Also to note, the GM 3 bar sensor reads great down to 18-20in vac, however there is a 3.3 bar sensor, but that one is rumored to be only good to 10in vac.

I would just pick up a GM 3 bar sensor. You'll be good up to 30lbs of boost, with good idle readings. Search the internet, but be sure its a genuine GM sensor. Also you'll need the pigtail, which I recommend getting a new one so you won't have any voltage drop.

 

[dsm10o0]

alright, thank you guys for the help. Figured out 1 of the sensor is 1 bar, but the other, cant find anything about it.

 

[prove_it]

I'm pretty positive the sensors will not work. You need a sensor from 1989 pontiac trans am turbo.

You'll have to bite the bullet and spend some cash. Check dsmtuners, you might snag a used one.