re: V6 intake

[James Montebello <jamesm@domain.elided>]

On Tue, 12 Nov 2002, Joe Elliott wrote:
> This overlooks the fact that the narrowest opening in the intake
> system is inside the airflow meter--considerably smaller than the AFM

Actually, the smallest area in the intake system is usually valve area.
I don't remember the valve sizes of the V6 off the top of my head,
nor have a measured port area, but in the majority of engines I have
measured, or seen measurements for, these usually restrict flow more than
throttle area or the area of the any part of the intake system upstream
of the throttle.  Increasing the area of any of these parts will have
no effect unless it's really the smallest part, and the throttle body
and AFM are rarely the smallest parts.

One should remember that inlet restrictors are a common form of power
limiting used in some classes of racing.  The restrictor used by the
DTM is a mere 28mm (1.1"), and these normally aspirated V8s make around
450bhp.  Peak power basically hinges on air intake, so increasing the
throttle body or AFM area beyond that of a 25mm round hole will make no
difference to peak power on a V6 until you make enough other modifications
to raise the power above 300bhp or so.

james montebello
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided