[s-cars] Stock boost levels?

[Calvin & Diana Craig]

Feico,

There is no reason to multiply gauge pressure by differences in ambient
pressure.  Gauge pressure is simply how much pressure on top of your ambient
pressure, i.e. your reference point, you are producing.  if you add the
gauge pressure to ambient it gives you absolute pressure referenced from a
pure vacuum, multiplication should not figure into this at all.

--Calvin

  -----Original Message-----
  From: FvAMI at aol.com [mailto:FvAMI at aol.com]
  Sent: Thursday, June 10, 2004 10:33 AM
  To: calvinlc at earthlink.net; 93UrS4 at rovershack.com; s-car-list at audifans.com
  Subject: Re: [s-cars] Stock boost levels?


  In a message dated 6/9/04 9:52:13 PM Pacific Daylight Time,
calvinlc at earthlink.net writes:



    When driving
    at 6k feet here in the South Denver Metro area, I normally see between
20
    and 21 psig with a stock chip at altitude.


  In your case you are ready "gauge pressure" ... which uses Atmospheric
pressure as its reference - so your "real" boost pressure is

  PSI = 21(reading gauge) * (Your Atmospheric Pressure/Sea Level Pressure)

  For all you folks with the digital stock gauge - if you have a 3.0 bar
sensor the absolute reading needs to be multiplied by the following to get
the approximate value

  Absolute PSI = reading * 3.0/2.5

  Generally - absolute pressure is the most interesting number - Gauge has
it benefits to determine pressure ratios for the turbo - but in terms of
estimated "power" absolute would be the number of interest.

  Best regards,
  Feico van der Laan