[Biturbos4] Bum Turbo??? Help me with the Gutless Wonder!

j y jimnetpa at yahoo.com
Thu Sep 1 12:48:48 EDT 2005

Thanks for the clarification, and accuracy.
For the un-informed, to calculate your boost from VAG-COM readings, you MUST take your given MBAR at a given RPM and subtract 1 BAR (14.7 psi - atmosphere) from that nbr. 
For example, VAG records 1.8 MBAR @2500 rpm, then the calculation would be 1.8 MBAR - 1 MBAR = .8 MBAR (your actual boost at that given rpm). VAG will provide a rough estimate of atmosphere when your S4 is idling (since there should be no load on your engine @ idle), and this will be as close to actual atmosphere (in your location) as possible, take this nbr from VAG Block 115 (mine usually reads 1010 to approximate 1 BAR.) and subtract it from the MBAR nbr that you get at higher RPMs (when there is a load on the engine). 
To get the PSI equivalent (if u don't own a boost gauge), you can use the following website to convert MBAR to PSI.

"j.koenig" <j.koenig at adelphia.net> wrote:
Just to be accurate, "MBAR" is milli-bar. 1 Bar (1000 mBar) = 14.7 psi = standard atmospheric pressure 

----- Original Message ----- 
From: "j y" 

2) If you aren't chipped - log channel 115 in VAG-COM to get your actual/requested boost. Non chiped boost should be less than 1 MBAR (14.7 psi). Chipped S4s can use this channel to see what the ECU is reading in terms of boost too. 
Biturbos4 mailing list
Biturbos4 at www.audifans.com

Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 

More information about the Biturbos4 mailing list