Bob,
I have large turbos on my TSIO-550 powered Super Legacy. I
normally fly with the wastegate controller set to minimum boost which has the capability
of giving me 45” of MP at sea level. If I were to set the wastegate
controller to maximum (as I do at the Reno Air Races) it will give me 75”
of MP at sea level.
So, if you have a wastegate controller that you can adjust I
would think you could easily have between 30” and 35” of MP
available at FL250.
Lynn Farnsworth
Super Legacy #235
TSIO-550 Powered
Race #44
MMO .60 Mach
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf Of Bob Rickard
Sent: Monday, July 02, 2012 9:36 PM
To: lml@lancaironline.net
Subject: [LML] IV-P High altitude performance question
Gents -
Looking for your inputs. What has been your experience
with respect to manifold pressure at altitudes above 20,000 feet?
Are you able to keep maximum MAP all the way up, and what is
your critical altitude where you start to see a drop?
And lastly, what cruise settings do you use once you get up
there?
I paid extra money for upgraded turbo's (from a Mirage,
which have bigger turbine wheels) in my engine rebuild, and want to see what my
expectations should be based on your experiences. If you happen to have a
TSIO-550-X from Barrett that has this modification I would be especially
interested in your experience up high. I fly long distance (> 1100
miles non stop) routinely and would love to get in the FL250 range.
Thanks for your inputs -