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Discussion Starter · #1 ·
Hi, I just got a dice unit and I was able to monitor boost pressure via VIDA. The reason I bought DICE was to fix a mystery issue after installing phuzzy's tcv (speed sensor reading missing, oddly after clearing the DTC's and logging the sensors nothing is wrong).

Anyhow my boost pressure @ idle is set at 1020HPA which translates into 14.7 PSI. At half throttle it is running @ 1240 HPA which equals 17.9 PSI. I have not tried WOT but I am guessing it would be around 20 PSI.

I find this odd because my car is not tuned, just a DP and intake. Does anybody else have the capability to compare my numbers to theirs so I can make sure everything is alright? Also is VIDA the correct tool to figure out boost pressure, a buddy of mine has a boost gauge and at idle it reads 0 or -.

Thanks in advance :thumbup:
 

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The intake resonator delete is all I've done and my stock boost peaks between 9-10psi.

At idle, it's all vacuum pressure and it tends to fluctuate based on outside temp and how hard the cars been running.

Not sure if that helps any :confused:
 

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uh you should have about -17psi vacuum at idle and a max of +10psi WOT. If you rev in park or N its should go to 0 and stop. Anything outside those parameters is BAD.
 

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i was having more or less the same issues as yours....
 

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Anyhow my boost pressure @ idle is set at 1020HPA which translates into 14.7 PSI. At half throttle it is running @ 1240 HPA which equals 17.9 PSI. I have not tried WOT but I am guessing it would be around 20 PSI.
That is your manifold pressure, and it's atmospheric, i.e. zero boost. Boost is the delta above atmospheric, and untuned you should see 9-10psi, or about 24psi absolute, under a hard pull. You will not see boost pressure rise much by revving the engine without load.
 

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Discussion Starter · #6 · (Edited)
Is VIDA an accurate way to read boost from the turbocharger or am I reading vacuum. In vida I monitor ECM ---> Boost pressure. Boost pressure could be a number of things lol. Doesn't make sense I would have boost @ idle

Edit: I have to measure multiple things to get the boost pressure. Taken from volvospeed:
Max Pressure Sensor Reading 1850 hPA = 26.83psi
Barometric pressure = 995 milbar = 14.4psi
26.83 - 14.4 = 12.4 psi Max Boost @ 4,400RPM

I figured the numbers were to high lol
 

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Looks like you figured it out, but just a note that you will never read vacuum with VIDA, because the MAP sensor is before the throttle flap. If you install a boost gauge to the manifold nipple, you'll be able to see vacuum - although I can't imagine why anyone would need to.

That information "from volvospeed" is incomplete btw. Barometric pressure varies by weather and elevation. You, in RI near sea level will generally see a higher baro, and you can read it with VIDA, btw. Also, I don't understand why it says "max pressure sensor reading". I guess these were observed values on a given day by some person? Did you see 12.4 boost from a stock tune? If so, was it sustained?
 

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Discussion Starter · #8 ·
Looks like you figured it out, but just a note that you will never read vacuum with VIDA, because the MAP sensor is before the throttle flap. If you install a boost gauge to the manifold nipple, you'll be able to see vacuum - although I can't imagine why anyone would need to.

That information "from volvospeed" is incomplete btw. Barometric pressure varies by weather and elevation. You, in RI near sea level will generally see a higher baro, and you can read it with VIDA, btw. Also, I don't understand why it says "max pressure sensor reading". I guess these were observed values on a given day by some person? Did you see 12.4 boost from a stock tune? If so, was it sustained?
I'll have to run it again, those numbers were somebody's from volvospeed, my max HPA is higher than that. If I am sustaining 12PSI on a stock tune is that bad? I will wait till my buddy comes by so he can work the computer while I drive otherwise it's a mess and a distraction
 

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isn't stock boost supposed to be around 9.2 psi - 10 psi?
 

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isn't stock boost supposed to be around 9.2 psi - 10 psi?
Yes but I've hit 12 to 15 before and it held for a while in 3rd and 4th gear going 40+mph

Sent from my iPhone4S using Tapatalk while on the toilet.
 

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If I am sustaining 12PSI on a stock tune is that bad?
Not necessarily, but it's on the high side and could indicate a TCV or wastegate issue. That said, it's not really a bad thing, if the car's doing ok otherwise.
 
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