2 bar tuning

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Aug 9, 2006 | 11:50 AM

#21

Lord Aries

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From: Greenville, SC

OK, i'll just go with the 2-Bar and let my tuner guy work his magic...

Aug 9, 2006 | 02:27 PM

#22

FlaBouy

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The only other info I know on the MAP sensors. This info is from the HPT site....

www.SummitRacing.com
PN# MSD-2313 3bar MAP
PN# MSD-2312 2bar MAP
PN# MSD-2311 1bar MAP

or

www.GMPartsDirect.com
PN# 12223861 3bar MAP
PN# 16040609 2bar MAP
PN# 16137039 1bar MAP

heres some other GM stuff

1 Bar
GM part # 2503679
standard part # AS-5
2 Bar
GM part # 16009886
Wells part # SU-129
standard part # AS-4
3Bar
GM part # 16040749

Aug 9, 2006 | 02:45 PM

#23

02sierraz71_5.3

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From: Cornelius, NC

Quote:

Originally Posted by dewmanshu

I ahve been screwing around with this alot lately...yesterday I changed it from 1 to 1.25. I am not having as much luck as everybody else. I do see the trends, but my trims move big time. At "1" I had average trims of -3 to +3 in most areas below 110kpa and when I moved it to 1.25 it went to lots of +'s, +5 to +7 in alot of areas. Then on the way home I turned the bias off. -7 to -12 was what I saw. HOLY crap. All IAT and this truck is pulling some fuel and closer to ECT and it is adding some fuel.

I thought the basis of this was more IAT temps more fuel. Which isn't always necessary. Mine is pulling tons of fuel with no "bias" at all. Hmmm.

Obviously going stft is the fix for anything under 110kpa, the pcm will fix it as per what it needs, but that confuses me as well, cause it isn't doing as the "theory" states with this bias.

I havent experimented with mine yet. I just set it to one and said the hell with it. From what I gathered with more bias towards ect or iat the PCM seems to over correct for fueling I think this is because the model for charge temps is incorrect for vehicles with extensive modifications like everyones on here. I think the means behind the charge modeling is to predict what the actual temp is that enters the cylinder, you would think they would just put the sensor closer and get rid of the modeling.

"airmass = VE.MAP/MAT

airmass = grams/cyl
VE = grams.Kelvin/kPa
MAP = kPa
MAT = Kelvin

MAT is the estimated manifold temperature, which in earlier OS's is simply the IAT, but in later OS's uses the blending of IAT and ECT dependant on airflow. The issue seems to be worse in the earlier OS's due to this fact. If you don;t see the "Use Complex Model" setting then its just using the IAT, even though there may be a bias table shown it's not used."
-chris at hpt

MAT is really the only variable that changes based on weather but its also estimated not emperical WTF? This is where modeling comes into play. And it directly effects airmass. I wish I could walk through the steps but I dont know enough yet.

Last edited by 02sierraz71_5.3; Aug 9, 2006 at 02:56 PM.

Aug 9, 2006 | 07:34 PM

#24

02sierraz71_5.3

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From: Cornelius, NC

Quote:

Originally Posted by trever1t

Just a small (may be way off track) question for you about 2bar tuning. If it deletes the MAF from calculating A/F then what or how does the PCM compensate for IAT's and Altitude changes?

Back to the question I got side tracked. This is a problem with running in Speed density. There is no way to account for the changes you are asking about. Thats why you will see different trims throughout the year between seasons.

Nov 24, 2006 | 04:06 PM

#25

TurboBerserker

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The PCM still accounts for IATs-- you *need* your IAT sensor plugged in and in the air stream. As far as altitude... Opps... Retune

Dec 27, 2006 | 02:14 PM

#26

SRT10KLLR

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From: California

Quote:

Originally Posted by FlaBouy

Quote:

Originally Posted by Wilde Racing

This is a "plug and play" MAP for up to 15 lbs boost:
GM P/N: 12580698 AC Delco: 213-1631

I am a little confused as to which number is the correct one for the 2 Bar MAP sensor. I have seen several different numbers for the same GM part number.

PN# 16040609 2bar MAP
2 Bar GM part # 16009886
GM P/N: 12580698