CIS airflow meter limits HP?

[Bruce Bell]

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Javad, It is just an interesting reference point, and it only addresses one
small part of the system as you point out. I just got curious and decided to
put a measuring stick to the claims of 1200 cfm or not more than 250/280 hp
due to air flow restriction in the meter.   Nothing more.

I used an estimate of 1.5 cfm/hp so by way of example  WR urq would require
about 300 cfm for 200 hp.

For those who haven't seen them, the series on "Negative Boost" at autospeed
is very good and quite relevant to this discussion. Especially when we look
at the plumbing of the whole system as Javad correctly wants to do.

Bruce

 -----Original Message-----
From: JShadzi at aol.com [mailto:JShadzi at aol.com]
Sent: Thursday, May 09, 2002 9:04 AM
To: bbell at surview.com; quattro at audifans.com; urq at audifans.com
Subject: Re: CIS airflow meter limits HP?


  Bruce, while the simple formulation is an interesting reference point, to
have any real idea of how much the airflow unit can actually flow, we'd have
to not only run some air through it on a flow bench, but also pressurize the
fuel dist to ensure proper control pressure is being enacted.  Also, with
the proper airboot in place, etc.

  My BTDT just doesn't support those kind of power levels (though I'd love
to believe it), at one point I was running 5 EFI injectors in addition to
the CIS system, so I was way past the fuel problems.  The fuel issue is
EASY, I wouldn't say the air flow discussion is officially over.

  Anyone have acess to a flow bench??

  Javad

  In a message dated 5/8/2002 10:20:07 PM Pacific Daylight Time,
bbell at surview.com writes:

   ....snip..bcb

    The question is, how much flow area is there... never mind I just got
off my
    a** and measured the Urq. 80 mm sensor plate 13 mm clearance on short
side
    and ~23 mm on the big side for an average of 18 mm for the flow area
around
    the circumference of the plate. This computes to 731.2 cfm or ~486 hp.
If
    you drop the velocity to a conservative 300 fps there is still nearly
500
    cfm or enough to easily clear 325 hp.

    I'll leave the issue of enough fuel to someone else...

    Bruce




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