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Old 10-23-2002, 05:20 PM   #1
codean
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Default Utec boost reading, how good is it?

Looking at some of the logs that I took I never reached over 14.1 psi. However my boost gauge is reading higher (15-15.5 psi). So which one should I trust more. The utec or my gauge.

BTW. My gauge is a 52mm defi link hooked up to the BOV line.
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Old 10-23-2002, 05:49 PM   #2
SpeedRacer-X
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My Defi V1 gauge is 1PSI off...

Shawn
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Old 10-23-2002, 06:19 PM   #3
8Complex

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Always trust the sensor... it's much more accurately calibrated then a mechanical gauge is.
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Old 10-23-2002, 09:15 PM   #4
jjunior887
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I'm having the same problem with mine, I was reading 14 or so stock now I'm reading about 1.5-2 psi higher than the Utec is seeing.-James
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Old 10-24-2002, 04:43 PM   #5
RiftsWRX
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Default Re: Utec boost reading, how good is it?

Quote:
Originally posted by codean
Looking at some of the logs that I took I never reached over 14.1 psi. However my boost gauge is reading higher (15-15.5 psi). So which one should I trust more. The utec or my gauge.

BTW. My gauge is a 52mm defi link hooked up to the BOV line.
Trust the UTEC... but make sure you've gone through the MAP calibrations in the manual.. a deltadash works GREAT for that.

Jorge (RiftsWRX)
www.ProjectWRX.com
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Old 10-24-2002, 04:45 PM   #6
JenisonWRX
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the stock sensor uses absolute MAP ... no reason to distrust it.

unless its a bad sensor
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Old 10-24-2002, 05:55 PM   #7
jjunior887
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anyone around Northern Va have a Delta Dash I could borrow for a few minutes?-James
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Old 10-24-2002, 06:09 PM   #8
radwrx
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My OEM boost guage is spot on with the UTEC.
-Mike
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Old 11-28-2002, 07:48 AM   #9
sdecker
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Bump for more info...

My UTEC reads consistently 1-2 psi less than my stock boost gauge. For now, I'm going to use the numbers that the UTEC shows...

I have a dyno appointment with Nathan this Saturday, so I'll try to get the definitive answer from him.

Anyone else have any info?

Scott
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Old 11-29-2002, 12:10 AM   #10
pace
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Like Jorge said, you need to calibrate your MAP sensor via the Gradient and Intercept constants as described in the manual. The stock values supplied with the unit are for a sea-level calibration, and as such your MAP will report low readings at any elevation above sea-level.

Once your MAP is calibrated it will report manifold pressure that is zero-referenced at your specific elevation. This information was gleaned through my observation of it zeroing at -4.5psi up here at 8000ft, and my subsequent experimentation with the calibration process.

Statements like "the stock sensor uses absolute MAP" are somewhat misleading. The UTec provides a functional transformation that translates the absolute MAP voltages to a relative PSI reading, using the Gradient and Intercept constants. These PSI readings only appear 'absolute' for Gradient and Intercept values that were configured at sea-level. Essentially these two constants provide you with a mechanism to zero-reference your specific MAP sensor at your specific location. Once calibrated, the MAP PSI values you see in the logs will then corroborate your relative boost readings shown on your gauges.

-Pace
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