Rick / Craig,
I have not had any compressor stalls with
the turbos on my aircraft. However, I don’t fly above FL 180 either. I
don’t use any special procedures for power reduction, but my normal power
reduction for descent from altitude is a stair step procedure. That is, I start
down, reduce 2 or 3 inches of MP, continue the descent a bit then pull off a
couple of more inches of MP.
Lynn Farnsworth
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Craig Berland
Sent: Thursday, May 31, 2007 11:35
AM
To: lml@lancaironline.net
Subject: [LML] Re: Sonic Valves
Rick, hopefully someone like Lynn Farnsworth will
comment. I have a IV-P that is not done/not flying. The input
I forwarded came from when I designed and machined new intercooler "end
caps" for some new intercoolers I decided to use. The input I got at
that time was…..Machine the boss but don't drill the sonic port hole in
the angled end cap because the end caps could be used in the Super
Legacy. I am very "engine" knowledgeable but I am NOT a turbo
expert. Frankly, just the opposite. It is possible the input I
received was aimed at the Reno
racers.
Craig Berland
Craig,
Thanks
for the info! Some follow-up questions...
Who
set up your engine? Lancair? Did you (they) get any
"official" input from TCM? Is there anything different in the
waste gate (slope) controller or turbos?
Do
you have any special power reduction procedures? (i.e. reducing MP slowly to
let Upper Deck Pressure bleed off)
Do
you have much experience with it up high (i.e. 25,000 ft)?
Perhaps
the banter regarding compressor stalls with the sonic nozzles plugged is OWT
(Old Wise Tale). However, know of several straight IV's
(non-P)
that still have sonic nozzles because they were told they needed them???
Rick