Well, youngster {:>), Gregg sounds like
he has the right combination. IF you are going to fly without boost
control (other than the throttle), then you want a turbo with a high a/r
(area/radius) ratio, larger than 1.0 in my opinion.
The same turbo with a small a/r (< 1.0)
will spin up faster with less exhaust/throttle and give you gobs of boost on the
low rpm engine – the problem is you must have some sort of boost control
or at WOT the boost will go high enough to damage the engine.
If you use a larger a/r, the turbo takes
more exhaust gas (read more throttle) to produce the boost, this generally
means low boost at low rpm (so not good for that sports car feel), but more
most and HP at the higher rpm where we generally are interested. If you
either have an example to follow (or can work with a turbo seller who will
permit you to swap in/out different a/r turbine housings), you can experiment
to find the best a/r for your installation and operating environment.
Another benefit of high a/r is that there
is less exhaust back pressure due to the more open channel through the turbine
housing.
But, if you are going to try that route,
make certain you start out with an a/r that you are confident is perhaps a tad
too large. You can always put on a smaller a/r to get more top end
performance – provide you have not blown your engine {>)
Ed
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of shipchief@aol.com
Sent: Saturday, February 13, 2010
11:09 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: N.A.
Renesis to turbo
IIRC the specs on the turbo is .71 A/R
and P trim. I called Turbonetics and told them the application was a 13b used
as a generator in a sound proof box that would have quite a pressure drop at
the air filter to overcome.....and be used on top of a mountain...!?!
The sales guy assured me that a 60-1 .71
A/R and P trim was the ticket.
Later I emailed Greg Richter of blue
mountain fame...he was running his Cozy with a 13b Turbo, and he was using
the same exact turbo?
Anyway, he had some mamoth Warnke 3 blade
that he could overspeed at will, and was looking for more bite.
I indicated that I planned to
use (some specific) blow off valve and waste gate, Greg said
why? do you need it? Don't put that stuff on your engine unless it needs it.
That left me in a quandry. I left them out for lightness and simplicity. I'll
add them if I have a demonstrated need. How ever that manifests it'self??
Remeber, I have a RD-1 with a 4 planet
set, so I should endevor to keep HP at or below 200. I'm supposedly way over
turbo'd. I don't have an intercooler for this reason. Self control will be
required.
Scott
PS. I'm only a few months from turning
55!!
-----Original
Message-----
From: Kelly Troyer <keltro@att.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat, Feb 13, 2010 7:31 am
Subject: [FlyRotary] N.A. Renesis to turbo
Sorry Scott............This was directed
at you !!..................<:)
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
--------------
Original message from "Kelly Troyer" <keltro@att.net>: --------------
Curious what the A/R ratio of your
"On Center" TO4 exhaust turbine housing is ?.............
Most of the recommendations from those of
the group flying ahead or behind the TO4 range
from about .96 to 1.15 A/R
ratio..............Will be interested in your rpm/mp numbers when
you get airborne................
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
--------------
Original message from shipchief@aol.com:
--------------
I'm just a bit ahead of where you want to
go, but way behind on the rest of the plane. I'm wingless in the garage at
home, test running in the yard with the tail tied to a cedar tree.
I'm building an RV-8 with a turbo 13b. I
welded up my own exhaust manifold mounting a Turbonetics 60-1 using an 'on
center' TO-4 turbine housing. The compresor faces forward and a cone
shaped K&N filter is direct mounted to the compressor housing. The exhaust
is an S shaped 2.25" pipe that crosses in front of the firewall and exits
out the center of the cooling air exit (cowl flap area) parrallel to the sheet
metal ramp. The pipe is supported with a clevis to the engine mount plate
(between the block and oil pan) so it all moves in harmony with the engine/turbo,
yet can grow a bit from heat. So far the turbo muffles the engine fairly
well.....but I have not gone to War Emergency Power.....yet.
I 'borrowed' David Leonards radiator advice, and mounted it under the chin,
making a fairly generous scoop, which I tested today.
the oil cooler is mounted on
the right side and uses the entire airflow from the right cowl cheek
opening. Separate air paths for radiator and oil cooler helped solve my
previous cooling failure.
I ground ran for 20 minutes today, building
up RPM as it warmed up, and the temps are stable. I chickened out and held at
3850 RPM for the last 5 minutes, the highest I've gone yet. water temp stable @
154F, Oil stable at 172F. Tracy's
engine monitor gives direct HP readout based on fuel flow, so it varies as you
adjust the mixture, but I ran up to about 50HP with firm temperature
control. This was very exciting for me becuase it's enough power that the
fuselage is starting to buck and shake like there might be some power there,
and promises of more.
I have not done anything with the left
cowl cheek opening yet. Air entering here goes right to the tubo air filter,
and washes over the fuel injectors, turbo assembly, and spills out the bottom
with the heated radiator air.
To keep from choking the heated radiator
air, I'm thinking of making a duct to carry the left cheek air out the left
side of the cowl, where I could mount an intercooler. I've trial fitted a stock
Mazda intercooler here, I would need to remake the air tubes into/out of
it. The important part of this is cooling the fuel system and isolating
the turbo heat from anything it could damage. Dave warned me of this early
on, and I have not forgotten it.
Constructive comments are always welcome!
PS, I'm working very hard to keep this
simple and light. Weight adds up fast!
=