Pros and Cons to 2 bar vs. 3 bar map??
2 bar is only up to 1 times atmospheric pressure soo ends up being like 14.7 psi of boost.... if your going over that. U should have a 3 bar. If your not planning on going that high then a 2 bar will give better accuracy....
Pulling this off top of my head soo someone please correct me if im wrong
Pulling this off top of my head soo someone please correct me if im wrong
2 bar can be more precise than the 3 bar for tuning. If it's under 15lbs I'd go 2 bar.
You only have 0-5 volts to tune in with. 2 bar cuts in in 1/2, 3 bar cut's it to a 1/3 on drivability table's.
You only have 0-5 volts to tune in with. 2 bar cuts in in 1/2, 3 bar cut's it to a 1/3 on drivability table's.
2 bar map plugs into stock location/harness. 3 bar usually requires the older style design and different weather pack connector.
2 bar can be used in applications where you run more than 15lbs of boost, but that is up to your tuner.
In my experience I have not noticed a difference in resolution issues when the 3 bar map is mounted correctly vs the factory style 2 bar.
2 bar can be used in applications where you run more than 15lbs of boost, but that is up to your tuner.
In my experience I have not noticed a difference in resolution issues when the 3 bar map is mounted correctly vs the factory style 2 bar.
FormerVendor
Joined: Dec 2001
Posts: 2,444
Likes: 2
From: WWW.SPEEDINC.COM
I always recommend just starting out and tuning it 3bar so you don't have to do it over in the future. Everyone says they'll never run over 15lbs of boost.....until they do 
2 bar is 15 to 210kpa 5kpa per cell. 400-8000rpm, 400rpm per cell
3 bar is 15 to 315kpa, 5kpa per cell between 15 and 105kpa, 10kpa per cell between 110 and 315kpa. 400-8000rpm, 400rpm per cell.
3bar is more resolution than you will ever need. I don't recall ever tuning one and saying "I wish I had another row that split this one by 5kpa".
2 bar is 15 to 210kpa 5kpa per cell. 400-8000rpm, 400rpm per cell
3 bar is 15 to 315kpa, 5kpa per cell between 15 and 105kpa, 10kpa per cell between 110 and 315kpa. 400-8000rpm, 400rpm per cell.
3bar is more resolution than you will ever need. I don't recall ever tuning one and saying "I wish I had another row that split this one by 5kpa".
It also comes down to the fact that any of the 3 bar map sensors out there are definitely less accurate than the 2 and 2.5 bar map sensors which I suppose is just inherent in the design of a sensor with a given range. Some of the calibrations also do penalize you by having a smaller truncated 3 bar VE table (20 kpa breakpoints in boost regions and missing the 20 kpa row all together) compared to the 2 bar like the 04 GTOs and some 03+ calibrations but on an 02-fbody you won't have that issue.
My preference is to use the newer 2.5 bar map sensor out there since it's accurate as hell and run a 3 bar OS.
My preference is to use the newer 2.5 bar map sensor out there since it's accurate as hell and run a 3 bar OS.
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FormerVendor
Joined: Dec 2001
Posts: 2,444
Likes: 2
From: WWW.SPEEDINC.COM
If you can tune a 3bar SD car to have perfect fuel trims in every cell up to 105kpa and then perfect air/fuel ratio at every boost level above that, I see no reasoning to back up any resolution argument.
JMO
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Verdad Gallardo so it seems like the biggest factor is how much boost you run and since i dont plan on going above 15lbs any time soon i should just go with a 2 bar since its also easier to install. does anyone have a part # for a 2 bar that plugs right in?
Good info. i never thought I'd go above 15psi, but saw 200kpa a couple times at 6900rpm with my procharger, well, until #7 ringland let go on the stock bottom end. Now that I am going forged, I'm thinking, hey, what's a couple more pounds of boost lol.
Chances are I'll drive it at this level for a while, but a 2.5 bar sensor does sound tempting as another 7psi of boost would put me at 21 or 22 psi of boost.
I didn't realize that the 3 bar map sensor had normal resolution in vacum, that would make normal drivability just as good as it is now.
Chances are I'll drive it at this level for a while, but a 2.5 bar sensor does sound tempting as another 7psi of boost would put me at 21 or 22 psi of boost.
I didn't realize that the 3 bar map sensor had normal resolution in vacum, that would make normal drivability just as good as it is now.
Good info. i never thought I'd go above 15psi, but saw 200kpa a couple times at 6900rpm with my procharger, well, until #7 ringland let go on the stock bottom end. Now that I am going forged, I'm thinking, hey, what's a couple more pounds of boost lol.
Chances are I'll drive it at this level for a while, but a 2.5 bar sensor does sound tempting as another 7psi of boost would put me at 21 or 22 psi of boost.
I didn't realize that the 3 bar map sensor had normal resolution in vacum, that would make normal drivability just as good as it is now.
Chances are I'll drive it at this level for a while, but a 2.5 bar sensor does sound tempting as another 7psi of boost would put me at 21 or 22 psi of boost.
I didn't realize that the 3 bar map sensor had normal resolution in vacum, that would make normal drivability just as good as it is now.
so hows that build comin anyways?
The duramax sensor is actually a 3.3 bar sensor, it plugs right in and is the stock style, and I would like to know if people are running these as well as I plan on going into higher boost this year and already have a duramax sensor waiting to go in!! The duramax sensor part number is 28074366. That is the delphi number on the sensor.
Dennis
Dennis
