Date:         Fri, 23 Jun 2006 13:43:03 -0700
Reply-To:     John Bange <jbange@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Bange <jbange@GMAIL.COM>
Subject:      Re: Fw: Re: ? for our mechanical wizards
In-Reply-To:  <014d01c69701$7ae49500$6501a8c0@mike>
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>
> > Assuming 100% volumetric efficiency, which no naturally-aspirated engine
> > can have...........
> >


Well yeah, but we're already thrust almost completely in the dark as the the
actual quantity of incoming air because we know the displaced volume, but
not the temperature and pressure (P1V2T2=P2V1T1, and suchlike). The ECU uses
TempI to get an idea of air temperature, and pressure integrates nicely with
volume from deflection of the AFM vane well enough, but without access to
any of the hard engineering numbers from the original VW flow bench tests
they used to generate the ECU fuel map it's hard to say exactly how many
pounds of air at STP are going through at any one time. I think all we can
definitively say is that it's something less than 525cc of STP air per
intake stroke (given  that a NA engine runs a bit of a vacuum in the intake
tract).

--
John Bange
'90 Vanagon - "Geldsauger"