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Discussion Starter · #1 ·
I came across this with a recent tune at http://ARFabrication.com

My Utec was showing a much lower number on my boost then my Defi.

I was hitting 25psi on my Defi, and the Utec had me at 22psi :confused:

Now what Howard is thinking is that the Utec is coming up with boost numbers by equation. Using maf sensors and other info. While the Defi is hooked right into the Turb.

So I'm thinking the Utec is probably of, while the Defi is accurate.....

What do you guys have say?
 

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pwn n00bs
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my defi is pretty accurate, where is yours tapped?

and furthermore, you were tuned you said? well what psi did the tuner tune the car at? don't tell me he didn't tell you...
 

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Discussion Starter · #5 ·
VSGTS14 said:
hmm dunno....that's a UTEC characteristic i'm not familiar with..
it's reading from the ECU right?

Right, whcih is why I'm figuring it may be off. I "assume" its calculating the psi, where as the Defi is tapped right in.

I made the switch today with no prob. Couple of twists and had her back down to 26psi, back on the meth with no knock.

Also, the Utec controls boost by fuel cut off right? Not like a manual set up which bleeds off. Being that when the utec has a programed amount of boost, when it reaches it the Fuel cuts off?

Thanks for the help VS
 

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Sweet I'm glad someone brought this up. I was working on a friend's car and his Blitz guages were reading up to 3 psi higher than the UTEC.
 

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As far as I understand, the UTEC is merely reporting the same boost that the ECU sees. I don't think there is a question of the UTEC being "off" unless you are questioning the accuracy of the stock sensors.

That said, the UTEC does report data in increments, and can miss a momentary (split second) spike. That would mean that the reported data might not tell the whole story of what data the ECU and UTEC are processing.
 

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Discussion Starter · #8 ·
Datadatum said:
As far as I understand, the UTEC is merely reporting the same boost that the ECU sees. I don't think there is a question of the UTEC being "off" unless you are questioning the accuracy of the stock sensors.

That said, the UTEC does report data in increments, and can miss a momentary (split second) spike. That would mean that the reported data might not tell the whole story of what data the ECU and UTEC are processing.
The big questions is how its read. The Utec uses the stock cpu, but its not read from a direct source as a gauge would, its calculated. The computer is using senors from things like the maf. While the gauge is a direct line into your turb.

I may be wrong about this, its just what we came up with, why there's is such a big difference, makes sence to me.

What do you think?
 

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pwn n00bs
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i'm still not sure....my avc-r reads from the ecu and it's the same as my defi reads which is tapped into the bov line.

it may just be the way UTEC likes to figure things out...however, i'd go by the defi instead.
 

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Discussion Starter · #10 ·
VSGTS14 said:
i'm still not sure....my avc-r reads from the ecu and it's the same as my defi reads which is tapped into the bov line.

it may just be the way UTEC likes to figure things out...however, i'd go by the defi instead.
I agree you with you 100%! I think that the Utec may be off in the way it reads the boost. Where as the Defi is a direct inline read, as you said.

Defi has been around for many years and a trusted source for accurate reading among the pros,and major car manufactures. Where as TurboXS is fairly new, not that the quality isn't there.

Anyway good topic, I'm enjoying this discussion with you guys!

So what about by curveball, in controlling the boost, Utec cutts fuel and a Man boost gauge bleeds, right?
 

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wdb said:
Defi gauges are rumored to read a pound or so high by some folks, I think the reason had to do with the elevation of the factory where the sensors are made. A search here and perhaps nabisco should turn up more.
my defi's read a bit high, 1 PSI higher.
 

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there is no such thing as a perfect sensor, every mesuring device is accurate to a specific value, and that mesurement is then sent to an analog gauge for you to try and interpret witout letting any parallax effect your judgement. i would trust the ecu's sensor for no other reason than its what your car can see. and thats what you have to tune with.................... now if they could get the utec to run a defi gauge chain
 
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