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Hmmm, only 16 hours and it is already not fast enough! :>)
The Renesis is not turboed from the factory. I think the reason might be
that the rotors are 10 to 1, not 9.7. I suspect that you should change
rotors if you turbo.
I am not flying and am amazed that you would want to jump back into building
so soon after getting in the air....but
If you want more performance, I suggest you go with a 20B instead of a
turbo. You could continue to fly while you build the engine on a mock up
firewall. As soon as everything is done, you could do a quick engine swap.
Probably take less than a couple of days and you would be back in the air.
This time with real horses...which within, maybe, 20 hours, will be too
slow! :>)
Bill B
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Don Wallker
Sent: Saturday, February 06, 2010 9:22 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] N.A. Renesis to turbo
Dear list, Turbo flyers and especially David Leonard,
I've 16 flying hours on my RV-8 with a Renesis and all of Tracy's stuff
and a Catto 76/88. The airplane flys great, just like an RV, no gliding
time, and about 36 hours on the ground.
SPECS
Full throttle 8,000' 174 mph indicated, 2450 on the prop, water 185,
oil 205,
Climb out 110 mph, rate of climb, 1250'/min. Field elevation 5046.
These are not bad numbers, but I would like better. I've been influenced by
some of the the local jet jocks who say that there is no
such thing as too much horsepower and they are right! N113BR seems to
be performing about like a 160-170 HP RV. So I am investigating turboing
it! The idea is to have a little better than sea level performance on take
off (designed for 210HP N.A.) and turbo normalizing at cruise. Up to 12000'
would be nice.
During the air races this year, Dave Leonard showed up and I was very
impressed by his airplane. He was able to turbo and inter cool it and have
it all inside an RV cowl, so I'll likely base my installation on his.
Plus, he has been through the learning curve of 3 or so turbos so he knows
what to do, what not to do and what would be better if he were to do it all
over again.
I've spent the afternoon looking through the archives, reading as much as I
can find about turbos, and downloading all the photos I can. Here is what I
am tentatively planning on doing.
Get one of Techwelding's Renesis exhaust flanges made from 304 SS and have
my local waterjet guy copy it and make one out of 321SS. I'll weld
321 SS and manifold it together and run it into the bottom of the turbo
that will sit right in front of the exhaust. The turbo will have additional
support. Run the turbo outlet air from it through a stock
RX-7 inter cooler sitting in front of the left cheek opening and then out to
the right side of the engine, probably routing it under the PSRU and then up
to a throttle body and manifold. Then four al tubes over the top of the
engine into a cut down and welded up stock RX-8 intake manifold. The
exhaust out of the turbo will run down and out in the usual center of the
back of the cowl opening. I am thinking of trying one of Burns Stainless
all SS mufflers. It is basically a glass pack, but instead of glass, they
are using stainless steel wool and they say it is holding up for the rotary
racers. They make it any length you want and is about 4 lbs with their SS
vs 9 lbs with the hushpower 2 I'm using now. The combustion air intake to
the turbo will be on the aft left side of the cowl via an NACA duct opening
as Dave's is.
The oil cooler will have to be moved to under the engine. I will build up a
fiberglass scoop, probably based on Van's scoop and modify it to have a
bigger opening and be farther forward, closer to the prop. I will probably
have the oil cooler made a little larger (Techwelding) than the one I have
now.
That's the basic idea at this point. I'll finalize my plan, prebuild as
much as possible before tearing the airplane apart and try for as little
down time as possible. I'm looking for the list's critique here, plus
questions that I will have missed. The following are a list of questions
that I have.
1. Which turbo should I use, which orientation and who should I use to
do the work, plus what is the approximate price? TO4 hybrid? Dave and
Steve Brooks mention BNR turbo as a modifier. Who manufactures the turbo?
2. What is the ideal situation with a waste gate? Full open or not, or, or?
3. I read about a N.O.oil line solenoid to the turbo bearings. I assume
that if the Turbo fails, you turn it on to the N.C. position to prevent oil
from being pumped down your exhaust? I assume the oil that is used is
routed back to the sump.
4. What size exhaust is optimum? It seems Dave is running 2.5 inch.
5. What size throttle body should I use and what would be a good one?
One throttle body or two?
4. What size injectors should I use, and where should the secondaries
be placed? Dave is using 480cc and staging is at 32 inches. Are you
using the same for the primaries and is there an idle problem with the
larger injectors?
5. Anyone out there turboing a Renesis? Anyone flying one?
6. My compression is 9.7 to 1. Any problems with this higher
compression ratio as long as I use an inter cooler and keep the boost no
higher than 35"?
And lot more questions, but that's all I can think of now.
So If any of you can add any thought, let me know.
Don Walker
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