DCOBALTSS

iTrader: (1)

Boosted 2.4s which map sensor are you using?

DFZ24

iTrader: (5)

I think is the lsj 2 map sensor

heathkidder

iTrader: (20)

Stock

OttawaMark

iTrader: (3)

The 2 bar from ZZP: - 2.4 LE5 MAP Sensor #10-01-00786

I believe they are out of the old 3800 GTPs, listed as 2 bar but from what i've heard it is actually 2.5

I also use this one for IATs: Home ť Shop ť Sensors ť Pressure Sensors ť Bosch 3 Bar TMap Map Sensor with IAT

ZZP one is connected to nipple on manifold according to ZZPs SC kit and the 3 bar is bolted onto manifold and spliced into MAF for accurate IATs

DCOBALTSS

iTrader: (1)

right now im using stock but sometimes i get P0121 throttle positioning sensor..

and at begining during tuning i was having with the map where it would just stop working i think..

So which one are you using now?
the zzp or the 3 bar one?

i want to get iat2 temps too

OttawaMark

iTrader: (3)

Both. The 3 Bar has an IAT sensor embedded and thats all I use that one for. I use the 2 bar ZZP one as the actual map sensor. I suppose I could have just used the 3 bar for both functions but was too lazy to recalibrate.

OttawaMark

iTrader: (3)

How are you guys using 1 bar maps in boost? AFR under boost needs to know the air charge with accuracy, I'm curious how you get around this.

hhrfreek

iTrader: (6)

I am using this one:

Home ť Shop ť Sensors ť Pressure Sensors ť Bosch 2.5 Bar TMap Map Sensor with IAT

I spliced the temp wires from the MAF so I just read IAT2 now. This sensor mounts in the stock location on the top left of the IM.

DCOBALTSS

iTrader: (1)

The max i had at full wot was 11psi

hhrfreek

iTrader: (6)

To read 11psi of boost you need a 2bar map sensor though. 11psi is actually ~25.5psi (14.5psi + 11psi). The stock 1 bar map sensor reads up to ~100kpa. At 11psi of boost your map is 176kpa which is beyond what the stock sensor should be able to accurately read.

...at least that is how I understand it.

OttawaMark

iTrader: (3)

1 Bar is between 12-15psi of atmospheric pressure depending on altitude. BOOST is anything above this, so if you are properly reading boost and showing 11psi you are actually between 13-26psi above zero atmospheric mass, which a 1 Bar does not read.

Atmospheric pressure - Wikipedia, the free encyclopedia

So, while a 1 bar measures up to 14.7...14.7 is what air at sea level already weighs, anything above this, as in BOOST will not be measured by a 1 Bar MAP sensor. And because it won't be measured, it can't be accounted for when the PCM is trying to inject the proper ratio of fuel to the actual amount of air entering the cylinders, which means under boost with a 1 Bar sensor you'll run lean, possibly even dangerously so.

2 Bar minimum, that way you'll be able to read up to 14.7psi of BOOST.

Correct.

heathkidder

iTrader: (20)

Im gonna use my stock one since many others have

noorj

iTrader: (17)

im pretty sure its done by straight maf tuning and not ve tables

DCOBALTSS

iTrader: (1)

Wow i dont understand.. maybe thats why i had some issues with my map when i was tuning the car.. well im gonna upgrade the map to another one which one u guys recommend if i want iat2

Dragonsfire12345

iTrader: (1)

I use the lsj map sensor

OttawaMark

iTrader: (3)

It is a hybrid, "VE" and SPEED DENSITY ( the E67 PCM no longer calculates old school VE, using GMVE instead which uses funky math like 5 dimensional polynomials). But, when going into POWER ENRICHMENT, which is where the BOOST usually comes on it uses the MAP sensor and engine RPM to enable PE mode.

Bottom line, they make 2 bar and up MAP sensors for boosted applications. USE THEM!

I'd recommend the one in freeks link, 2.5 bar. Using HP Tuners go to

ENGINE DIAGNOSTICS->AIRFLOW

You'll see under MAP sensor: MAP Sensor Linear and MAP Sensor Offset

Change to these values
Offset -> 20 kPa at 0.40V
Linear -> 250 kPa at 4.65V

The IAT curve is close to stock, I didn't touch mine.

Doomstar

Basically, just by rewiring the LSJ's 2.5 with this Diagram :
https://www.cobaltss.net/gallery/fil...ingDiagram.jpg
You end up reading IAT2 through an Interceptor? Nothing Tuning wise? Never saw an actual Proof,
Just some talk again..

hhrfreek

iTrader: (6)

I switched to this setup to help me tune. We call it IAT2, but your PCM is still reading it as IAT(since all you did was move the sensor). This allows you to add/pull timing based on actual temperature of the air when it enters the engine. IATs are almost always ambient at the MAF so that info does nothing for us since we slapped on a SC. My IAT2 are always 30* more than ambient and after a few pulls just watch them climb...I can bring my IAT2 up 80* over ambient after 3-4 gear pulls and that is only 10-15sec of WOT...if your not compensating for the increase in temp by pulling timing you're going to have kr issues.

OttawaMark

iTrader: (3)

IAT2 is an LSJ/LNF thing, the LE5 only reads IAT so as freek says you need to read it post boost (where the heat is) so the appropriate spark advance correction can be made. Up to 6* of timing can be pulled using stock IAT Spark Advance Correction tables, enough to stop KR before it starts hopefully.

mmcgee123

iTrader: (1)

Stock

DCOBALTSS

iTrader: (1)

So you dont have any issue since its a 1 bar sensor..

OttawaMark

iTrader: (3)

Well he did blow a sleeve and fubar a block on only 12psi of boost. Who is going to be tuning you anyways?

One more reason to use a 2 bar, if your MAF craps out you'll revert to SD and you want a MAP sensor that reads properly if you drop the hammer. Usually, if the MAF does crap out it throws a code but I've seen enough vids with Check Engine Lights, likely those guys don't know what codes they are throwing and no way of knowing if another one gets triggered with the light already on.

mmcgee123

iTrader: (1)

Trifecta tuned n im sure i blew a sleeve bc of that right Not the running 15psi multiple times and having a 100 shot of nitrous for over a year and a half

DCOBALTSS

iTrader: (1)

Im tuned with trifecta too..

And sometimes i get a P0121 code, and my idle is ****. When im driving and go to a stop gear to neural, the idle would go down like 400 then bounce to 600 then 500 then like finally stabilize to approx 900

that really pisses me off..

do you guys know what could be the problem,

mmcgee123

iTrader: (1)

I've never had that issue we had some idle things to figure out when I went e85 bur no problems now