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!
=