From: kenpowell@comcast.net
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] today's turbo musings
Date: Wed, 24 Sep 2003 02:15:56 +0000
Message-ID: <auto-000002600975@logan.com>

Rusty, just as a sanity check; the companies makeing centrifugal superchargers 
for the Ford Mustang go up to 5 lbs of boost without an intercooler.  All of 
the units developing more than 5 lbs use an intercooler.

Ken Powell
> Howdy all,
>  
> Well, I took a couple intercoolers to the hanger, and tried them on for
> size.  The FC model would probably go in the right cheek, without too much
> effort, though I'm worried that I'll pressurize the back of my radiator and
> oil cooler if I let too much air flow through it.  What to do, what to do...
>  
> I also did some more research on charge temps, and intercooler
> effectiveness.  It seems that 70F is about the best temp drop that you can
> hope for with a good intercooler, at high boost.  Unfortunately, size
> counts, and neither the FC nor FD intercooler is what would be considered
> "good".   Adequate might even be a stretch, especially for the FD model.  In
> the scheme of things, <=70F really isn't a deal breaker, and I'm starting to
> believe it falls in the category of refinement, more than necessity, when
> talking about 10 psi or less of boost, particularly when the higher boost is
> only used at frigid altitudes.  Turbo Tom considers it a necessity, but I
> have to wonder what his criteria is.  If I had a car, and were limited to X
> psi of boost, I would consider intercooling necessary to make the most power
> possible.  Since I should easily have more power than I could ever need, I
> don't see the intercooler being quite as essential.  
>  
> What does this all mean.  Well, I'm going to fly it like it is, and use up
> to 5 psi for takeoff.  At altitude, I'll go for the gusto, but will try to
> limit myself to 50" MAP, or 12 psi of boost over ambient, whichever comes
> first.  This should make a world of difference, and I can move on to
> something else.  
>  
> Cheers,
> Rusty 
>