Boost pressure help

m444ty p

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• Nov 27, 2009

• #1

I have a 2000 model s3, the only mods are a cone filter. The car had a new turbo a few months ago before i bought it. My snap on tool dealer let me borrow a solous pro scanner for the weekend. With the scanner you can take live data readings. So i pluged the scanner in and off down the road i went.

In 3rd gear the scanner showed the car was holding 1740 mbar boost pressure.

According to this site http://www.sensorsone.co.uk/pressure-units-conversion.html

I am running 25.237 psi !!!

I have had cossies, skylines etc and know what high boost feels like and my car dosent feel that quick.

please help

 

jm-baker

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• Nov 27, 2009

• #2

That will be absolute pressure (Gauge pressure + Atmospheric pressure).

The Gauge pressure that you are interested is that value minus just over 1000 millibar. so 0.74 bar for example.

 

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rossbrownlee

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• Nov 28, 2009

• #3

Sorry mate but JM baker is right...

You are running 1740 mBarA (absolute) NOT 1740 mBarG (gauge)

atmospheric pressure is 1013 mbarG so unless I am way off the mark here then you are running 1740 - 1013 = 727 mBar.

this is equal to roughly 10.5psi.

 

m444ty p

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• Nov 28, 2009

• #4

So how much boost is the car running?

 

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rossbrownlee

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• Nov 28, 2009

• #5

rossbrownlee said:

atmospheric pressure is 1013 mbarG so unless I am way off the mark here then you are running 1740 - 1013 = 727 mBar.

this is equal to roughly 10.5psi.

Click to expand...

 

m444ty p

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• Nov 28, 2009

• #6

sorry didnt see that post, is that boost ok?

 

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rossbrownlee

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• Nov 28, 2009

• #7

not sure to be honest mate, i don't have anything to compare it against.

sounds quite low to me but someone else will be able to tell you better.

 

S3 Nattie

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• Nov 28, 2009

• #8

Well my AMK spikes to about 14 psi and hold 11.5 psi till about 6000 rpm.

Dont know if that is right for a AMK but thats what mine is doing.

 

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Essflee

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• Nov 28, 2009

• #9

m444ty p said:

sorry didnt see that post, is that boost ok?

Click to expand...

A standard S3 should boost aprox 1 bar / 14psi, natties seems about right then dropping and holding 11.5psi, so yours could be a little low possibly...