Bob,
I am waiting on a clarification from "Turbonetics" as to what size turbine wheel
would turn the least rpm as altitude increases.............I know the turbine housing
a/r ratio is a big factor effecting turbine rpm as we climb but it is not clear to me
how the turbine wheel diameter and trim factor in.............Air density lessens with
altitude but I am not smart enough to know if the larger or smaller turbine wheel
will have the highest rpm because of this factor as we climb ??.........
Perhaps I am being anal about this but and you are probably correct that that the
effect of a 3mm diameter difference between the two turbine wheels is slight and
probably inconsequential...........If any of our multi-talented group members would
like to shine some light on this please jump in here !!..........
On another note do you happen to have any photos of your 13B/turbo installation
during construction that you would care to share with the group ??..........You have
a beautiful (to Rotorheads) and well thought out installation which from your report
is working very well and I am sure others of the group would like to plagiarize.....<:)
Best Regards,
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
From: "Rogers, Bob J." <BRogers@FDIC.gov>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Fri, August 13, 2010 11:49:06 AM
Subject: [FlyRotary] Re: Turbo Questions
Kelly,
I do not know which wheel is in my turbo. I expect the larger wheel (68 mm) to turn a little more slowly, since it has a larger surface area to absorb the exhaust, but it should not make much difference. Either one should be OK. The Turbonetics people can probably explain the performance differences between the two wheel sizes.
Bob
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Kelly Troyer
Sent: Thursday, August 12, 2010 3:44 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Turbo Questions
Thanks much for the info.................Just one more question..............Info from "Turbonetics"
says the 1.15 a/r turbine housing is limited to the F1-65 mm or F1-68 mm turbine wheel.......
Do you have info as to what turbine wheel was installed in your 60-1 turbo ??..............
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
From: "Rogers, Bob J." <BRogers@FDIC.gov>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, August 12, 2010 1:39:26 PM
Subject: [FlyRotary] Re: Turbo Questions
Kelly,
I limit my takeoff power to no more than 42 “ of manifold pressure (“MP”), usually just 40” . At altitudes of 5,000 feet and above, I generally run no more than about 36 “ MP (15 GPH) and 180 knots. Engine RPM is about 5,800. The turbo is capable of considerably more boost than this, but I have to watch engine water and oil temps at higher power settings. I do not want to run more than 200 degrees on oil or water and prefer 180 degrees. I can maintain these temps (even on hot days) with cowl flap settings from closed to full open as long as I keep the power settings at or below those described above. One day, I climbed to 11,000 feet and my GPS groundspeed (with a slight tailwind) was 213 knots. MP was 36”, RPM 6,000. I have a 68” diameter x 84 pitch
Prince P-tip fixed pitch prop coupled to the RWS 2.17/1 reduction unit.
Bob