Message-ID: <40854A2F.9080808@bellsouth.net>
Date: Tue, 20 Apr 2004 12:05:03 -0400
From: Mike Robert <pmrobert@bellsouth.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: intake ideas?
References: <list-3180765@logan.com>
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Tracy Crook wrote:

> One more comment on intake manifolds & race results.   Do not ignore 
> the benefits of a really clean air inlet with ram air recovery BEFORE 
> the manifold.   At 1125 ft  msl, 220 IAS, I saw manifold pressures 
> around 31.8" Hg.  Ignore this factor and you throw away about 6% 
> "free" horsepower.
>  
> Al,  I forgot to comment on your last note about your MAP tap in 
> manifold.  I think it is highly possible you were seeing errors 
> induced by air stream eddies or some other unpredictable factors 
> caused by that location.   It is a challenge to get MAP 
> measurements when you have no real plenum, only runners with high 
> velocity air.
>  
> Tracy

I have personally encountered this problem in a ground-bound rotary. 
Solved by connecting taps from each runner and running the resulting 
single line through a cheap plastic generic fuel filter(C) and MIG 
jet(R) before the MAP sensor. Basically, a physical RC network.

    -Mike